CONGENITAL MYOPATHY
&
CONGENITAL MUSCULAR
DYSTROPHY
BY- ABDUL QAVI
SR NEUROLOGY
Outline:
Congenital myopathy: Definition, classification, clinical
features, differential diagnosis, investigations,
management.
Approach to a case of floppy infant
Congenital muscular dystrophy: Definition, classification,
clinical features, investigations, management.
Recent advances
Summary
Definition of congenital myopathy:
The term “congenital myopathy” is applied to muscle
disorders presenting in infancy with generalized
muscle weakness and hypotonia followed by delayed
developmental milestones.
Neurol J Southeast Asia 2001; 6. Clinical and pathologic aspects of
congenital myopathies Ikuya NONAKA MD
Background:
 First report of a congenital myopathy was in 1956, when a patient
with central core disease (CCD) was described.
 In 1969, Dubowitz clarified the classification with his delineation of
new myopathies later termed congenital myopathy.
 The myopathy has been differentiated diagnostically on the basis of
their morphologic characteristics.
 With the advent of electron microscopy, enzyme histochemistry,
immunocytochemistry, molecular genetic analysis , a number of
morphologically distinct congenital myopathies have grown.
 The mode of inheritance and gene loci are variable.
Epidemiology:
Worldwide:
Incidence:6 per 100,000 live births or 1/10th of all
neuromuscular disorders. (wallgreen peterson 1990)
0.06% of all muscle diseases( ischizo nishino 2007)
Regional studies in Northern Ireland and Western
Sweden suggest prevalence between 3.5–5.0/100,000
in a pediatric population (Jungbluth H. Orphanet J Rare Dis
2007;2:31. )
India:
 1.12% of the muscle disease( Deepali jain,
Rohit Bhatia 2008)
Characteristic features:
 Onset in early life with hypotonia, hyporeflexia, generalized
weakness that is more often proximal than distal,
 Poor muscle bulk
 Dysmorphic features
 Relatively non-progressive
 Hereditary
 Unique morphological features on histochemical or ultrastructural
examination of the muscle biopsy sample that originate within
the myofiber
 Some cases have been reported as adult onset or as a progressive
Classification:
North K. What's new in congenital myopathies?. Neuromuscul
Disord. Jun 2008;18(6):433-42
1. Myopathies with protein
accumulation
a. Nemaline myopathy
b. Myosin storage myopathy
c. Cap disease
d. Reducing body myopathy
2. Myopathies with cores
a. Central core disease
b. Core-rod myopathy
c. Multiminicore disease
3. Myopathies with central
nuclei
a. Myotubular myopathy
b. Centronuclear myopathy
4. Myopathies with fiber size
variation
Congenital fiber type disproportion
Congenital Myopathies with identified gene loci:
Disorder inheritance Protein/gene chromosome
1. Nemaline
myopathy
a. NEM I
b. NEM2
c. NEM3
AD
AR
AD/AR/Sporadic
α-tropomyosin 3
Nebulin
alpha-actin
1q22-q23
2q21-q22
1q42.1
2. Central core
disease
AD/Sporadic Ryanodine(RYR1) 19q13.1
3. Core rod myopathy AD Ryanodine(RYR1) 19q13.1
4. Congenital
myopathies with
cores
AR Ryanodine(RYR1) 19q13.1
5. Myotubular
myopathy
X linked Myotubularin Xq28
6. Multi minicore AR Selenoprotein N 1p36
7. Hyaline body
myopathy
AD Cardiac myosin heavy
chain
14q11.2
Incidence of congenital myopathy
(1979-2000: National Center of Neurology and Psychiatry)
Neurol J Southeast Asia December 2001
Types of congenital myopathy Number of patients (%)
Nemaline myopathy 121 (27%)
Severe infantile form 43
Benign congenital form 53
Adult onset form 25
Central core disease 27 (6%)
Myotubular (centronuclear) myopathy 42 (9%)
Severe infantile myotubular myopathy 30 (7%)
Congenital fiber type disproportion 89 (20%)
Congenital myopathy without specific
features
31 (7%)
Miscellaneous 109 (24%)
Congenital myopathies: A clinicopathological study of 25 cases
Deepali Jain, Rohit Gulati
IJPM 2008
Type % cases
Central core disease 24
Multiminicore 20
Nemaline 20
CFTD 16
Centronuclear 12
Desminopathy 8
Congenital myopathies: Clinical and Pathological Study.
Annals of Indian Academy of Neurology, 2007 by N. Gayathri, A. Nalini, F.
Thaha
Type of myopathy No of cases (total 39)
Centronuclear 18
CFTD 15
Nemaline 2
Central core 2
Multiminicore 1
Tubular aggregates 1
Floppy infant
Clinical signs in a floppy infant
 Observation of a ‘frog-leg’ posture.
 Reduced spontaneous movement, with the legs fully abducted and
arms lying beside the body either extended or flexed
 Significant head lag on traction or pull-to-sit manoeuvre and
excessively rounded back when sitting (>33 weeks)
 Rag-doll posture on ventral suspension
 Vertical suspension test – feeling of ‘slipping through the hands’ when
the infant is held under the arms
 Various associated examination findings such as flat occiput or
congenital dislocation of the hips, arthrogryposis
Hypotonia pith frog position
Hypotonia
Differential diagnosis
Indicators of hypotonia of central
origin
• Social and cognitive impairment
• Dysmorphic features
• Fisting of hands
• Normal or brisk tendon reflexes
• Features of pseudobulbar palsy
• brisk jaw jerk
• crossed adductor response or
scissoring on vertical suspension
• Features that may suggest an
underlying spinal dysraphism
• History suggestive of HIE, birth
trauma or symptomatic
hypoglycaemia
• Seizures
Indicators of peripheral hypotonia
• Delay in motor milestones with
relative normality of social and
cognitive development
• Family history of neuromuscular
disorders/maternal myotonia
• Reduced or absent deep tendon
jerks and increased range of joint
mobility
• Frog-leg posture or ‘jug-handle’
• Myopathic facies (open mouth with
tented upper lip, poor lip seal when
sucking, lack of facial expression,
ptosis and restricted ocular
movements)
• Muscle fasciculation
Investigations
Laboratory Studies
 Creatine kinase level
 Normal or mildly elevated.
 Moderately in central core disease (CCD) and also in asymptomatic
carriers of the ryanodine receptor mutation in CCD.
Other Tests
 Electromyography and nerve conduction studies
 Nerve conduction study is normal.
 EMG is normal or shows myopathic pattern.
 Rule out other diseases such as spinal muscular atrophy, congenital
myasthenia, and hereditary neuropathy.
 Electrocardiography (ECG)
 Imaging: Ultasound, MRI of the muscle may be helpful.
 Procedures
 Muscle biopsy: Gold standard
 Light microscopy(H/E stain), Gomori trichrome stain, enzyme
histochemistry, immunocytochemistry.
 Ultrastructural examination of muscle is often necessary, since several
of the pathologic features are based on the EM appearance of muscle.
 Genetic analysis:
 Not required for diagnosis
 Very sensitive and specific in CCD
 Only a research level tool
Nemaline myopathy:
 Shy et al and Conen et al first described the disease in 1963
 Classified into 3 major forms including the
1) severe infantile (congenital)
2) benign congenital (mild, nonprogressive or slowly progressive)
3)adult onset forms
 Incidence: 0.2 per 1000 live births
 More common in finland and 1 in 500 in Amish community
 o.53% of all muscle disease and 22.6% of all congenital
myopathies. (MC Sharma, S Gulati Neurology India 2007)
 6 Genetic types
Genetics
Disorder inheritance Protein/gene
1. NEM I AD α-tropomyosin 3
2. NEM 2 AR Nebulin
3.NEM 3 AD/AR/Sporadic alpha-actin
4. NEM 4 AD β-tropomyosin
5. NEM 5 AR Troponin T1
6. NEM 7 AR Cofilin 2
Severe infantile
(congenital) form
Benign congenital form Adult onset form
•Muscle weakness and
hypotonia at birth.
•Facial muscle
involvement
•elongated,
emotionless expression
•high arched palate
•usually die before 1 year
of age
• respiratory failure or
infection ccommon.
•Cardiomyopathy rare
•Seizures rare
•Floppy infants
with delayed
developmental milestones
•Neck flexor weakness is
prominent
•95% patients
generalized
or predominantly proximal
muscle weakness
•5% weakness
predominantly distal
non-progressive or only
slowly Progressive
•Respiratory muscles
•Non progressive
minimal facial muscle
involvement
•Minimal proximal muscle
weakness
•Benign course
Head lag
Investigations
 Sr CK normal o minimally elevated
 Increased echogenecity in affected muscles on muscle USG
 Myopathic pattern on EMG
 Muscle MRI reveals patchy fatty degeneration of muscle
groups
 Histopathology diagnostic
 Genetic analysis
Nemaline bodies
Gomori trichrome stain H/E Stain
Electron microscopy
Central core disease:
 Term coined by Greenfield in 1958
 Mutation in the ryanodine receptor(CH 19q12.q13.2)
Typical presentation
 Autosomal dominant inheritance.
 Onset is at birth or in early childhood
 Nonprogressive limb weakness, mild facial weakness,
and hypotonia.
 Skeletal abnormalities include congenital hip
dislocation, kyphoscoliosis, and foot deformities.
Other presentations
Autosomal recessive (and autosomal dominant) inheritance
have been described with several different presentations.
Presentation in infancy includes generalized weakness and
atrophy, external ophthalmoplegia, and bulbar and
respiratory weakness.
Asymptomatic individuals may also present with a high
creatine kinase (CK) level or malignant hyperthermia.
About 25% of patients with CCD are susceptible to malignant
hyperthermia
Investigations
 Sr CK- Normal to mildly elevated
 Muscle ultrasound- increase in echogenecity
 Muscle MRI-selective involvement of following thigh muscles-
sartorius, adductor magnus, gastrosoleus, peroneal group.
 Muscle pathology:
 Oxidative stains: cores are hypostained
 Electron microscopy: excessive disorganisation of sarcomeres in
the cores, severe fragmentation and decrease of Z bands.
 Genetic analysis: PCR for CCD-RYR1 gene mutation(>60% positive)
Oxidase staining: Central cores
Central core disease - ultrastructural disorganization (Z-band
streaming).
Centronuclear myopathy
 Defined pathologically by the presence of central nuclei in
increased number of fibres.
 First reported as myotubular myopathy by spiro et al in 1966.
 AD, AR and X linked forms
X linked form
The most common is the severe X-linked form due to a mutation in
myotubularin.
At birth, severe weakness and hypotonia, feeding difficulty, and
respiratory distress are present.
Bilateral ptosis, facial weakness, and ophthalmoplegia are
common.
Skeletal features include pectus carinatum, knee and hip
contractures, elongated birth length, narrow face, and
macrocephaly.
Systemic features may include cryptorchidism, pyloric stenosis,
gallstones, hepatic dysfunction, spherocytosis, renal calcinosis.
The prognosis is poor
 At least one third of those affected dying in the first
year of life.
 Seventy-five percent of survivors older than 1 year
need ventilatory support
Most carriers are asymptomatic.
AR variant
Mutations in amphiphysin 2.
Features include hypotonia, proximal weakness, facial
weakness, ptosis, and ophthalmoplegia.
Other features can include contractures and dilated
cardiomyopathy.
The course is slowly progressive, with more than 50%
of patients surviving childhood.
AD variant:
Mutations in dynamin 2 (DNM2)
Most patients have a mild phenotype
Onset in adolescence or adulthood
Axial as well as distal more than proximal limb
weakness and slow progression.
Facial weakness, high-arched palate, ptosis,
ophthalmoplegia, joint hyperlaxity, and contractures
are common.
Benign couse
MUSCLE PATHOLOGY IN
CENTRONUCLEAR MYOTUBULAR
Minicore (multicore) myopathy
 So named because of the presence of core structures in the muscle
fibres.
 Autosomal recessive
 Around half of cases caused by a genetic error in one of two genes-
Selenoprotein N1 (SEPN1) and Ryanodine receptor 1 (RYR1).
 4 Variants:
 Classic form
 Progressive form with hand involvement.
 Antenatal form with arthrogryposis multiplex congenita (AMC).
 Ophthalmoplegic form
Prognosis: variable course
Diagnosis :
Histopathology:
• More type 1 fibres than type 2.
• Within these fibres, there are structures which are called ‘cores’;
which can be seen under the microscope.
These structures are not specific to minicore myopathy, and so
the clinical signs must be considered together with the muscle
sample to give a diagnosis of minicore myopathy
Congenital fibre type disproportion:
 Rare disease first described by Brooke
 Autosomal recessive
 Genetics: mutation in TPM3(75%), Selenoprotein N(1O%) and
ACAT1(10%)
 Child presents as presents as hypotonia, delayed motor
milestones and dysmorphic facies.
 Other clinical features can include facial, bulbar, and respiratory
weakness; short stature; low body weight
 Multiple joint contractures; scoliosis; long, thin face; and high-
arched palate.
HISTOPATHOLOGY:
Summary:
Type Facial
muscle
ptosis Ext
ophthalmo
plegia
Respirator
y
Skeletal
deformity
cardiac
Nemaline +++ +++ - +++ ++ +
CCD ++ + - + +++ +
Core rod + + - - ++ -
myotubular +++ +++ +++ +++ ++ -
Centronuclear ++ ++ ++ +++ +++ -
Multiminicore +++ + + +++ +++ ++
CFTD ++ - - + +++ -
Sarcotubular ++ - - - - -
Reducing body ++ ++ - +++ ++ -
Special clinical features:
Clinical feature Congenital myopathy
Cramps CCD
Myopathy with tubular aggregates
Calf hypertrophy Centronuclear myopathy
Myasthenic fatures Myopathy with tubular aggregates
Malignant hyperthermia CCD, Core rod
Multimini core
Neonatal lethal form X linked myotubular
Nemaline
Cardiomyopathies associated with congenital myopathies
Cardiomyopathy Myopathy
Hypertrophic
Nemaline myopathy
Multicore myopathy
Cytoplasmic body myopathy
Desminopathy
Myofibrillar myopathy
Danon’s disease
Dilated Nemaline myopathy
CentronucIear myopathy
CFTD
Desminopathy
Restrictive Desmin myopathy
Myofibrillar myopathy
Multicore myopathy
Floppy infant with pred proximal
weakness, hyporeflexia,
dysmorphic facies
Nemaline
Ptosis,
ophthalmoplegia,
respiratory
involvement
Cramps, ptosis,
cardiomyopathy
Congenital
myopathy
Facial muscle &
neck flexor
weakness,
respiratory
Contractures ,
Bulbar,
respiratory
weakness
CFTD
Myotubular
and
centronuclear
Central
core
disease
Clinical suspicion
of Cong myopathy
NCS normal/EMG
Myopathic
Confirmation of
diagnosis
Muscle Biopsy:
LM, IHC, EHC,EM ,
Genetic analysis
Sr.CK,
NCS/EMG Sr CK elevated
in Central core
disease
Treatment:
• No definitive treatment.
• Physiotherapy, occupational therapy
• Use of splints, braces and orthosis
• Contracture release, corrective surgeries.
• Chest physiotherapy, prevention and management of
aspiration pneumonitis, non invasive ventilation.
• Nutrition and gastrostomy feeding.
• Management of heart failure.
Congenital muscular dystrophy
• 1903, Batten described 3 children who had proximal muscle weakness
from birth whose biopsy showed chronic myopathic changes
• In 1908, Howard coined the term congenital muscular dystrophy
(CMD) when he described another infant with similar features.
• Ullrich first described the combination of joint hyperlaxity and proximal
contractures in 1930 in the German literature; which is known as
Ullrich congenital muscular dystrophy.
• In 1960, Fukuyama et al described a common congenital muscular
dystrophy in Japan that always had features of muscular dystrophy and
brain pathology.
Congenital muscular dystrophies are characterised by
 Autosomal recessive disease
 severe proximal weakness at birth
 slowly progressive or nonprogressive.
 Contractures are common
 CNS abnormalities can occur.
 Muscle biopsy shows signs of dystrophy
Muntoni and Voit 2004
Group Disorder Gene locus Gene Protein
I Laminin α2 deficiency 6q2 LAMA2 Laminin a2
II.1 Fukuyama MDC 9q3 FUKUTIN Fukutin
II.2 MEB disease 1p3 POMGnT1 Omannosyl GlcNac
transferase
II.3 Walker Warburg 9q34 POMT1 Omannosyl
transferase
II.4 CMDIc/LGMD2I 19q13 FKRP Fukutin related
protein
II.5 CMD1B 1q42 ? ?
II.6 CMD1D 22q LARGE Glycosyl transferase
III.1 Rigid spine muscular
dystrophy
1p35 SEPN1 Selenoprotein N
III.2 Ullrich CMD 21q22 COL6A1,A2 Collagen 6a1,a1
IV Integrin a7 deficiency ? INTEGRIN a7 Integrin a7
V Rare forms ? ? ?
Genetic defects
• The incidence of CMD has been estimated at 4.7 x 10-5 and its
prevalence at 6.8 x 10-5 (Mostacciuolo et al. 1996 Genetic
epidemiology of congenital muscular dystrophy in a sample from
north-east Italy).
• The estimated prevalence is approximately 7-12 cases per 100,000
children.
• In Japan, Fukuyama congenital muscular dystrophy is fairly common.
It is approximately 50% as common as Duchenne muscular
dystrophy.
• Few cases from India. ( Merosin negative congenital muscular
dystrophy: a short report. Ralte AM, Sharma MC, Gulati S, Das M,
Sarkar C)
DIFFERENTIAL DIAGNOSIS:
 Congenital Myopathies
 Dystrophinopathies
 Emery-Dreifuss Muscular Dystrophy
 Limb-Girdle Muscular Dystrophy
 Metabolic Myopathies
 Spinal Muscular Atrophy
Congenital muscular dystrophy with laminin-α2 deficiency
(MDC1A, classic CMD, merosin-deficient CMD)
 Accounts for 40-50% of all MDC.
 Mutation on chr 6 in the LAMA2 gene that codes for laminin-
α2.
 More than 90 different missense, nonsense, splice-site, and
deletion mutations have been described.
 Expression of laminin-α2 is related to disease severity.
 Laminin-α2 is expressed in the basement membrane of
striated muscle, cerebral blood vessels, Schwann cells, and
skin
• At birth or in the first few months of life, patients may have severe
hypotonia, weakness, feeding difficulty, and respiratory insufficiency.
• Contractures are common.
• External ophthalmoplegia may occur late.
• Most infants eventually sit unsupported, but standing is rare.
• Weakness is static or minimally progressive
• Complications are related to respiratory compromise, feeding
difficulty, scoliosis, and (in approximately one third) cardiopulmonary
disease.
• A sensory motor demyelinating neuropathy is present in many
patients, but it may not be clinically relevant.
CLINICAL FEATURES
• CNS manifestations may be present.
– Mild mental retardation or perceptual-motor difficulties
– Seizures occur in up to 30% of patients.
– White-matter changes, most often in periventricular
– Structural brain changes include enlargement of the
lateral ventricles, focal cortical dysplasia, occipital
polymicrogyria and/or agyria, and hypoplasia of the pons
and/or cerebellum.
Investigations
 Sr CK- moderately high
 Brain MRI- T2 Hyperintense white matter changes.
 Histopathology: Variable fibe size
Increased endomysial connective tissue.
Increased internal nuclei, hypercontracted
fibres.
 Muscle laminin staining: Specific.
Images:
Merosin + Merosin - Somewhat
Merosin -
Fukuyama CMD
• Autosomal recessive disease
• Mutation in the fukutin gene on 9q
• Most common in Japan and rare elsewhere in the world.
• Fukutin is a putative glycosyltransferase. .
• Patients with Fukuyama congenital muscular dystrophies have
complete loss (or nearly complete loss) of glycosylated α-
dystroglycan in the brain and muscle.
• Present in utero with poor fetal movements.
• Characteristics: generalised weakness, abnormal eye function,
mental retardation and seizures.
• Progressive weakness and respiratory failure ensue, with death
usually occurring in the mid teens.
• Cardiac disease develops after age 10 years, resulting in dilated
cardiomyopathy and congestive heart failure.
• Severe cases may cause retinal detachment, microphthalmos,
cataracts, hyperopia, or severe myopia.
• Cerebral changes are always present.
Type II lissencephaly is the characteristic finding in this
disease, as in all other glycosyltransferases.
Abnormalities range from cobblestone polymicrogyria and/or
pachygyria to complete agyria due to neuronal migration
abnormalities.
Dysplasia of the pyramidal tracts is common.
Ventricular dilation, if present, is mild.
Delayed myelination is noted on MRI.
Cerebellar cysts are common.
Brain imaging in FCMDAjay Garg, Sheffali Gulati Neurology India December 2004 Vol
52 Issue 4
Fukuyama CMD
 severely retarded, had many
seizures
 marked contractures of the
limbs.
 too weak to support her own
weight.
 disease was nonprogressive.
 Her two brothers also had the
same illness
Investigations:
• Moderate to marked elevation in Sr.CK
• Myopathic EMG
• MRI Brain
• HISTOPATHOLOGY AND IMMUNOHISTOCHEMISTRY:
• Histology of muscle: Essentially a picture of dystrophic
myopathy.
• Immunohistochemistry: Decreased staining for dystrophin-
associated proteins and for merosin.
Muscle eye brain disease
• Mutations in POMT1, POMT2, POMGnT1, fukutin, and FKRP can cause
this syndrome.
• In a series of 92 patients with congenital muscular dystrophy, 14 were
found to have muscle-eye-brain disease/Fukuyama congenital muscular
dystrophy phenotype.(Godfrey C, Clement Brain. Oct 2007;130(Pt 10).
• Seizures are common.
• CNS abnormalities are always present, including moderate-to-severe
mental retardation.
• Eye abnormalities are similar but more severe than those of Fukuyama
CMD.
• Cerebral changes are similar to those of Fukuyama CMD.
Walker-Warburg syndrome
 Mutations in all 6 glycotransferases have resulted in this most
severe form of congenital muscular dystrophy.
 Most severe of all alpha dystroglycanopaties.
 Eye abnormalities include microphthalmos, hypoplastic optic
nerve, ocular colobomas, retinal detachment, cataracts,
glaucoma, iris malformation, and corneal opacities, all of
which lead to blindness.
 Brain abnormalities include complete type II lissencephaly
with agyria.
HIERARCHY OF ORGAN INVOLVEMENT IN ALPHA
DYSTROGLYCANOPATHY
CEREBRUM
EYES
PONS
CEREBELLUM
STRIATEDMUSCLE
Rigid-spine syndrome with muscular dystrophy
 Autosomal recessive
 Mutation in the selenoprotein N gene (SEPN1).
 Presentation is at birth or within the first year of life
 Scapular winging and facial and bulbar weakness are common.
 Contractures usually develop at age 3-10 years.
 Respiratory insufficiency is common and progressive
 Muscle weakness is slowly progressive.
 The cardiac system is usually normal.
 Intelligence and brain MRIs are normal.
Ullrich congenital muscular dystrophy
 Autosomal recessive (or more rarely dominant) disorder
 Mutation in 1 of the 3 collagen type VI genes (COL6A1, COL6A2,
COL6A3).
 Typical features include presentation in the neonatal period
 with hypotonia, kyphosis of the spine, proximal joint
contractures, torticollis, and hip dislocation.
 Distal joint hyperlaxity with a protruding calcaneus
 Weakness involves distal more than proximal muscles.
 Progressive disability, usually due to contractures, leads to loss of
ambulation after 2-10 years.
 Respiratory insufficiency invariably develops in the first or second
decade.
 Facial dysmorphism is common and includes micrognathia, a round
face with drooping of the lower lids, and prominent ears.
 Skin changes can include follicular hyperkeratosis, keratosis pilaris,
and keloids.
 Intelligence and brain MRIs are normal.
 Cardiac function is normal.
UCMD: Report of nine cases from India
A Nalini, N Gayatri
Neurology India 2009
Muscle
weakness,contractures,cogni
tive decline, seizures
CMD
MEB
Walker Warburg
Fukuyama CMD
Eye involvement, brain
malformations, raised CK
Distal > proximal weakness, distal
joint hyperlaxity, proximal
contractures, skin changes
Ullrich’s
CMD
Proximal> distal
weakness
RSMD
Merosin def
CMD
Management
 No specific treatment is available for any of the congenital
muscular dystrophies.
 Aggressive supportive care is essential to preserve muscle
activity, to allow for maximal functional ability, and to prolong
the patient's life expectancy.
 Management of pulmonary and cardiac problems.
Non invasive ventilation:
G tube implantation:
Physiological and most acceptable way of feeding for long
term
Surgical Care
• Orthopedic surgery is often necessary in patients who live several years
with their disease to prevent contractures and scoliosis
Post scoliosis Surgery:
Gene therapy
 Agrin which binds to laminin and to α-drystroglycan might be
able to functionally rescue the weakened muscle caused by
LAMA2 mutations.
 The Agrin transgene improved the general health, lifespan and
locomotory activity of the mutant mice.

This study demonstrates the potential for gene therapy using
non-homologous proteins that functionally compensate for gene
mutation.
Summary
 Congenital myopathies not so uncommon in india, and an
important diagnosis to be considered in a floppy infant
 Muscle histopathology is the gold standard for diagnosis.
 Of the congenital muscular dystrophies, only merosin
deficiency and Ullrich’s CMD are reported from india.
 Contractures, Brain involvement and dystrophic changes in
muscle are the hallmark of CMD
 Gene therapy in the coming years can bring in a definite
solution to the problems.
Thank
you

Congenital myopathy

  • 1.
  • 2.
    Outline: Congenital myopathy: Definition,classification, clinical features, differential diagnosis, investigations, management. Approach to a case of floppy infant Congenital muscular dystrophy: Definition, classification, clinical features, investigations, management. Recent advances Summary
  • 3.
    Definition of congenitalmyopathy: The term “congenital myopathy” is applied to muscle disorders presenting in infancy with generalized muscle weakness and hypotonia followed by delayed developmental milestones. Neurol J Southeast Asia 2001; 6. Clinical and pathologic aspects of congenital myopathies Ikuya NONAKA MD
  • 4.
    Background:  First reportof a congenital myopathy was in 1956, when a patient with central core disease (CCD) was described.  In 1969, Dubowitz clarified the classification with his delineation of new myopathies later termed congenital myopathy.  The myopathy has been differentiated diagnostically on the basis of their morphologic characteristics.  With the advent of electron microscopy, enzyme histochemistry, immunocytochemistry, molecular genetic analysis , a number of morphologically distinct congenital myopathies have grown.  The mode of inheritance and gene loci are variable.
  • 5.
    Epidemiology: Worldwide: Incidence:6 per 100,000live births or 1/10th of all neuromuscular disorders. (wallgreen peterson 1990) 0.06% of all muscle diseases( ischizo nishino 2007) Regional studies in Northern Ireland and Western Sweden suggest prevalence between 3.5–5.0/100,000 in a pediatric population (Jungbluth H. Orphanet J Rare Dis 2007;2:31. )
  • 6.
    India:  1.12% ofthe muscle disease( Deepali jain, Rohit Bhatia 2008)
  • 7.
    Characteristic features:  Onsetin early life with hypotonia, hyporeflexia, generalized weakness that is more often proximal than distal,  Poor muscle bulk  Dysmorphic features  Relatively non-progressive  Hereditary  Unique morphological features on histochemical or ultrastructural examination of the muscle biopsy sample that originate within the myofiber  Some cases have been reported as adult onset or as a progressive
  • 8.
    Classification: North K. What'snew in congenital myopathies?. Neuromuscul Disord. Jun 2008;18(6):433-42 1. Myopathies with protein accumulation a. Nemaline myopathy b. Myosin storage myopathy c. Cap disease d. Reducing body myopathy 2. Myopathies with cores a. Central core disease b. Core-rod myopathy c. Multiminicore disease 3. Myopathies with central nuclei a. Myotubular myopathy b. Centronuclear myopathy 4. Myopathies with fiber size variation Congenital fiber type disproportion
  • 9.
    Congenital Myopathies withidentified gene loci: Disorder inheritance Protein/gene chromosome 1. Nemaline myopathy a. NEM I b. NEM2 c. NEM3 AD AR AD/AR/Sporadic α-tropomyosin 3 Nebulin alpha-actin 1q22-q23 2q21-q22 1q42.1 2. Central core disease AD/Sporadic Ryanodine(RYR1) 19q13.1 3. Core rod myopathy AD Ryanodine(RYR1) 19q13.1 4. Congenital myopathies with cores AR Ryanodine(RYR1) 19q13.1 5. Myotubular myopathy X linked Myotubularin Xq28 6. Multi minicore AR Selenoprotein N 1p36 7. Hyaline body myopathy AD Cardiac myosin heavy chain 14q11.2
  • 10.
    Incidence of congenitalmyopathy (1979-2000: National Center of Neurology and Psychiatry) Neurol J Southeast Asia December 2001 Types of congenital myopathy Number of patients (%) Nemaline myopathy 121 (27%) Severe infantile form 43 Benign congenital form 53 Adult onset form 25 Central core disease 27 (6%) Myotubular (centronuclear) myopathy 42 (9%) Severe infantile myotubular myopathy 30 (7%) Congenital fiber type disproportion 89 (20%) Congenital myopathy without specific features 31 (7%) Miscellaneous 109 (24%)
  • 11.
    Congenital myopathies: Aclinicopathological study of 25 cases Deepali Jain, Rohit Gulati IJPM 2008 Type % cases Central core disease 24 Multiminicore 20 Nemaline 20 CFTD 16 Centronuclear 12 Desminopathy 8
  • 12.
    Congenital myopathies: Clinicaland Pathological Study. Annals of Indian Academy of Neurology, 2007 by N. Gayathri, A. Nalini, F. Thaha Type of myopathy No of cases (total 39) Centronuclear 18 CFTD 15 Nemaline 2 Central core 2 Multiminicore 1 Tubular aggregates 1
  • 13.
    Floppy infant Clinical signsin a floppy infant  Observation of a ‘frog-leg’ posture.  Reduced spontaneous movement, with the legs fully abducted and arms lying beside the body either extended or flexed  Significant head lag on traction or pull-to-sit manoeuvre and excessively rounded back when sitting (>33 weeks)  Rag-doll posture on ventral suspension  Vertical suspension test – feeling of ‘slipping through the hands’ when the infant is held under the arms  Various associated examination findings such as flat occiput or congenital dislocation of the hips, arthrogryposis
  • 14.
  • 15.
  • 16.
  • 17.
    Indicators of hypotoniaof central origin • Social and cognitive impairment • Dysmorphic features • Fisting of hands • Normal or brisk tendon reflexes • Features of pseudobulbar palsy • brisk jaw jerk • crossed adductor response or scissoring on vertical suspension • Features that may suggest an underlying spinal dysraphism • History suggestive of HIE, birth trauma or symptomatic hypoglycaemia • Seizures Indicators of peripheral hypotonia • Delay in motor milestones with relative normality of social and cognitive development • Family history of neuromuscular disorders/maternal myotonia • Reduced or absent deep tendon jerks and increased range of joint mobility • Frog-leg posture or ‘jug-handle’ • Myopathic facies (open mouth with tented upper lip, poor lip seal when sucking, lack of facial expression, ptosis and restricted ocular movements) • Muscle fasciculation
  • 19.
    Investigations Laboratory Studies  Creatinekinase level  Normal or mildly elevated.  Moderately in central core disease (CCD) and also in asymptomatic carriers of the ryanodine receptor mutation in CCD. Other Tests  Electromyography and nerve conduction studies  Nerve conduction study is normal.  EMG is normal or shows myopathic pattern.  Rule out other diseases such as spinal muscular atrophy, congenital myasthenia, and hereditary neuropathy.  Electrocardiography (ECG)
  • 20.
     Imaging: Ultasound,MRI of the muscle may be helpful.  Procedures  Muscle biopsy: Gold standard  Light microscopy(H/E stain), Gomori trichrome stain, enzyme histochemistry, immunocytochemistry.  Ultrastructural examination of muscle is often necessary, since several of the pathologic features are based on the EM appearance of muscle.  Genetic analysis:  Not required for diagnosis  Very sensitive and specific in CCD  Only a research level tool
  • 21.
    Nemaline myopathy:  Shyet al and Conen et al first described the disease in 1963  Classified into 3 major forms including the 1) severe infantile (congenital) 2) benign congenital (mild, nonprogressive or slowly progressive) 3)adult onset forms  Incidence: 0.2 per 1000 live births  More common in finland and 1 in 500 in Amish community  o.53% of all muscle disease and 22.6% of all congenital myopathies. (MC Sharma, S Gulati Neurology India 2007)  6 Genetic types
  • 22.
    Genetics Disorder inheritance Protein/gene 1.NEM I AD α-tropomyosin 3 2. NEM 2 AR Nebulin 3.NEM 3 AD/AR/Sporadic alpha-actin 4. NEM 4 AD β-tropomyosin 5. NEM 5 AR Troponin T1 6. NEM 7 AR Cofilin 2
  • 23.
    Severe infantile (congenital) form Benigncongenital form Adult onset form •Muscle weakness and hypotonia at birth. •Facial muscle involvement •elongated, emotionless expression •high arched palate •usually die before 1 year of age • respiratory failure or infection ccommon. •Cardiomyopathy rare •Seizures rare •Floppy infants with delayed developmental milestones •Neck flexor weakness is prominent •95% patients generalized or predominantly proximal muscle weakness •5% weakness predominantly distal non-progressive or only slowly Progressive •Respiratory muscles •Non progressive minimal facial muscle involvement •Minimal proximal muscle weakness •Benign course
  • 24.
  • 25.
    Investigations  Sr CKnormal o minimally elevated  Increased echogenecity in affected muscles on muscle USG  Myopathic pattern on EMG  Muscle MRI reveals patchy fatty degeneration of muscle groups  Histopathology diagnostic  Genetic analysis
  • 26.
  • 27.
  • 28.
    Central core disease: Term coined by Greenfield in 1958  Mutation in the ryanodine receptor(CH 19q12.q13.2) Typical presentation  Autosomal dominant inheritance.  Onset is at birth or in early childhood  Nonprogressive limb weakness, mild facial weakness, and hypotonia.  Skeletal abnormalities include congenital hip dislocation, kyphoscoliosis, and foot deformities.
  • 29.
    Other presentations Autosomal recessive(and autosomal dominant) inheritance have been described with several different presentations. Presentation in infancy includes generalized weakness and atrophy, external ophthalmoplegia, and bulbar and respiratory weakness. Asymptomatic individuals may also present with a high creatine kinase (CK) level or malignant hyperthermia. About 25% of patients with CCD are susceptible to malignant hyperthermia
  • 30.
    Investigations  Sr CK-Normal to mildly elevated  Muscle ultrasound- increase in echogenecity  Muscle MRI-selective involvement of following thigh muscles- sartorius, adductor magnus, gastrosoleus, peroneal group.  Muscle pathology:  Oxidative stains: cores are hypostained  Electron microscopy: excessive disorganisation of sarcomeres in the cores, severe fragmentation and decrease of Z bands.  Genetic analysis: PCR for CCD-RYR1 gene mutation(>60% positive)
  • 31.
  • 32.
    Central core disease- ultrastructural disorganization (Z-band streaming).
  • 33.
    Centronuclear myopathy  Definedpathologically by the presence of central nuclei in increased number of fibres.  First reported as myotubular myopathy by spiro et al in 1966.  AD, AR and X linked forms
  • 34.
    X linked form Themost common is the severe X-linked form due to a mutation in myotubularin. At birth, severe weakness and hypotonia, feeding difficulty, and respiratory distress are present. Bilateral ptosis, facial weakness, and ophthalmoplegia are common. Skeletal features include pectus carinatum, knee and hip contractures, elongated birth length, narrow face, and macrocephaly. Systemic features may include cryptorchidism, pyloric stenosis, gallstones, hepatic dysfunction, spherocytosis, renal calcinosis.
  • 35.
    The prognosis ispoor  At least one third of those affected dying in the first year of life.  Seventy-five percent of survivors older than 1 year need ventilatory support Most carriers are asymptomatic.
  • 36.
    AR variant Mutations inamphiphysin 2. Features include hypotonia, proximal weakness, facial weakness, ptosis, and ophthalmoplegia. Other features can include contractures and dilated cardiomyopathy. The course is slowly progressive, with more than 50% of patients surviving childhood.
  • 37.
    AD variant: Mutations indynamin 2 (DNM2) Most patients have a mild phenotype Onset in adolescence or adulthood Axial as well as distal more than proximal limb weakness and slow progression. Facial weakness, high-arched palate, ptosis, ophthalmoplegia, joint hyperlaxity, and contractures are common. Benign couse
  • 38.
  • 39.
    Minicore (multicore) myopathy So named because of the presence of core structures in the muscle fibres.  Autosomal recessive  Around half of cases caused by a genetic error in one of two genes- Selenoprotein N1 (SEPN1) and Ryanodine receptor 1 (RYR1).  4 Variants:  Classic form  Progressive form with hand involvement.  Antenatal form with arthrogryposis multiplex congenita (AMC).  Ophthalmoplegic form
  • 40.
    Prognosis: variable course Diagnosis: Histopathology: • More type 1 fibres than type 2. • Within these fibres, there are structures which are called ‘cores’; which can be seen under the microscope. These structures are not specific to minicore myopathy, and so the clinical signs must be considered together with the muscle sample to give a diagnosis of minicore myopathy
  • 41.
    Congenital fibre typedisproportion:  Rare disease first described by Brooke  Autosomal recessive  Genetics: mutation in TPM3(75%), Selenoprotein N(1O%) and ACAT1(10%)  Child presents as presents as hypotonia, delayed motor milestones and dysmorphic facies.  Other clinical features can include facial, bulbar, and respiratory weakness; short stature; low body weight  Multiple joint contractures; scoliosis; long, thin face; and high- arched palate.
  • 42.
  • 43.
    Summary: Type Facial muscle ptosis Ext ophthalmo plegia Respirator y Skeletal deformity cardiac Nemaline+++ +++ - +++ ++ + CCD ++ + - + +++ + Core rod + + - - ++ - myotubular +++ +++ +++ +++ ++ - Centronuclear ++ ++ ++ +++ +++ - Multiminicore +++ + + +++ +++ ++ CFTD ++ - - + +++ - Sarcotubular ++ - - - - - Reducing body ++ ++ - +++ ++ -
  • 44.
    Special clinical features: Clinicalfeature Congenital myopathy Cramps CCD Myopathy with tubular aggregates Calf hypertrophy Centronuclear myopathy Myasthenic fatures Myopathy with tubular aggregates Malignant hyperthermia CCD, Core rod Multimini core Neonatal lethal form X linked myotubular Nemaline
  • 45.
    Cardiomyopathies associated withcongenital myopathies Cardiomyopathy Myopathy Hypertrophic Nemaline myopathy Multicore myopathy Cytoplasmic body myopathy Desminopathy Myofibrillar myopathy Danon’s disease Dilated Nemaline myopathy CentronucIear myopathy CFTD Desminopathy Restrictive Desmin myopathy Myofibrillar myopathy Multicore myopathy
  • 46.
    Floppy infant withpred proximal weakness, hyporeflexia, dysmorphic facies Nemaline Ptosis, ophthalmoplegia, respiratory involvement Cramps, ptosis, cardiomyopathy Congenital myopathy Facial muscle & neck flexor weakness, respiratory Contractures , Bulbar, respiratory weakness CFTD Myotubular and centronuclear Central core disease
  • 47.
    Clinical suspicion of Congmyopathy NCS normal/EMG Myopathic Confirmation of diagnosis Muscle Biopsy: LM, IHC, EHC,EM , Genetic analysis Sr.CK, NCS/EMG Sr CK elevated in Central core disease
  • 48.
    Treatment: • No definitivetreatment. • Physiotherapy, occupational therapy • Use of splints, braces and orthosis • Contracture release, corrective surgeries. • Chest physiotherapy, prevention and management of aspiration pneumonitis, non invasive ventilation. • Nutrition and gastrostomy feeding. • Management of heart failure.
  • 49.
    Congenital muscular dystrophy •1903, Batten described 3 children who had proximal muscle weakness from birth whose biopsy showed chronic myopathic changes • In 1908, Howard coined the term congenital muscular dystrophy (CMD) when he described another infant with similar features. • Ullrich first described the combination of joint hyperlaxity and proximal contractures in 1930 in the German literature; which is known as Ullrich congenital muscular dystrophy. • In 1960, Fukuyama et al described a common congenital muscular dystrophy in Japan that always had features of muscular dystrophy and brain pathology.
  • 50.
    Congenital muscular dystrophiesare characterised by  Autosomal recessive disease  severe proximal weakness at birth  slowly progressive or nonprogressive.  Contractures are common  CNS abnormalities can occur.  Muscle biopsy shows signs of dystrophy
  • 51.
    Muntoni and Voit2004 Group Disorder Gene locus Gene Protein I Laminin α2 deficiency 6q2 LAMA2 Laminin a2 II.1 Fukuyama MDC 9q3 FUKUTIN Fukutin II.2 MEB disease 1p3 POMGnT1 Omannosyl GlcNac transferase II.3 Walker Warburg 9q34 POMT1 Omannosyl transferase II.4 CMDIc/LGMD2I 19q13 FKRP Fukutin related protein II.5 CMD1B 1q42 ? ? II.6 CMD1D 22q LARGE Glycosyl transferase III.1 Rigid spine muscular dystrophy 1p35 SEPN1 Selenoprotein N III.2 Ullrich CMD 21q22 COL6A1,A2 Collagen 6a1,a1 IV Integrin a7 deficiency ? INTEGRIN a7 Integrin a7 V Rare forms ? ? ?
  • 52.
  • 53.
    • The incidenceof CMD has been estimated at 4.7 x 10-5 and its prevalence at 6.8 x 10-5 (Mostacciuolo et al. 1996 Genetic epidemiology of congenital muscular dystrophy in a sample from north-east Italy). • The estimated prevalence is approximately 7-12 cases per 100,000 children. • In Japan, Fukuyama congenital muscular dystrophy is fairly common. It is approximately 50% as common as Duchenne muscular dystrophy. • Few cases from India. ( Merosin negative congenital muscular dystrophy: a short report. Ralte AM, Sharma MC, Gulati S, Das M, Sarkar C)
  • 54.
    DIFFERENTIAL DIAGNOSIS:  CongenitalMyopathies  Dystrophinopathies  Emery-Dreifuss Muscular Dystrophy  Limb-Girdle Muscular Dystrophy  Metabolic Myopathies  Spinal Muscular Atrophy
  • 55.
    Congenital muscular dystrophywith laminin-α2 deficiency (MDC1A, classic CMD, merosin-deficient CMD)  Accounts for 40-50% of all MDC.  Mutation on chr 6 in the LAMA2 gene that codes for laminin- α2.  More than 90 different missense, nonsense, splice-site, and deletion mutations have been described.  Expression of laminin-α2 is related to disease severity.  Laminin-α2 is expressed in the basement membrane of striated muscle, cerebral blood vessels, Schwann cells, and skin
  • 56.
    • At birthor in the first few months of life, patients may have severe hypotonia, weakness, feeding difficulty, and respiratory insufficiency. • Contractures are common. • External ophthalmoplegia may occur late. • Most infants eventually sit unsupported, but standing is rare. • Weakness is static or minimally progressive • Complications are related to respiratory compromise, feeding difficulty, scoliosis, and (in approximately one third) cardiopulmonary disease. • A sensory motor demyelinating neuropathy is present in many patients, but it may not be clinically relevant.
  • 57.
    CLINICAL FEATURES • CNSmanifestations may be present. – Mild mental retardation or perceptual-motor difficulties – Seizures occur in up to 30% of patients. – White-matter changes, most often in periventricular – Structural brain changes include enlargement of the lateral ventricles, focal cortical dysplasia, occipital polymicrogyria and/or agyria, and hypoplasia of the pons and/or cerebellum.
  • 58.
    Investigations  Sr CK-moderately high  Brain MRI- T2 Hyperintense white matter changes.  Histopathology: Variable fibe size Increased endomysial connective tissue. Increased internal nuclei, hypercontracted fibres.  Muscle laminin staining: Specific.
  • 59.
  • 60.
    Merosin + Merosin- Somewhat Merosin -
  • 61.
    Fukuyama CMD • Autosomalrecessive disease • Mutation in the fukutin gene on 9q • Most common in Japan and rare elsewhere in the world. • Fukutin is a putative glycosyltransferase. . • Patients with Fukuyama congenital muscular dystrophies have complete loss (or nearly complete loss) of glycosylated α- dystroglycan in the brain and muscle.
  • 62.
    • Present inutero with poor fetal movements. • Characteristics: generalised weakness, abnormal eye function, mental retardation and seizures. • Progressive weakness and respiratory failure ensue, with death usually occurring in the mid teens. • Cardiac disease develops after age 10 years, resulting in dilated cardiomyopathy and congestive heart failure. • Severe cases may cause retinal detachment, microphthalmos, cataracts, hyperopia, or severe myopia.
  • 63.
    • Cerebral changesare always present. Type II lissencephaly is the characteristic finding in this disease, as in all other glycosyltransferases. Abnormalities range from cobblestone polymicrogyria and/or pachygyria to complete agyria due to neuronal migration abnormalities. Dysplasia of the pyramidal tracts is common. Ventricular dilation, if present, is mild. Delayed myelination is noted on MRI. Cerebellar cysts are common.
  • 64.
    Brain imaging inFCMDAjay Garg, Sheffali Gulati Neurology India December 2004 Vol 52 Issue 4
  • 65.
    Fukuyama CMD  severelyretarded, had many seizures  marked contractures of the limbs.  too weak to support her own weight.  disease was nonprogressive.  Her two brothers also had the same illness
  • 66.
    Investigations: • Moderate tomarked elevation in Sr.CK • Myopathic EMG • MRI Brain • HISTOPATHOLOGY AND IMMUNOHISTOCHEMISTRY: • Histology of muscle: Essentially a picture of dystrophic myopathy. • Immunohistochemistry: Decreased staining for dystrophin- associated proteins and for merosin.
  • 67.
    Muscle eye braindisease • Mutations in POMT1, POMT2, POMGnT1, fukutin, and FKRP can cause this syndrome. • In a series of 92 patients with congenital muscular dystrophy, 14 were found to have muscle-eye-brain disease/Fukuyama congenital muscular dystrophy phenotype.(Godfrey C, Clement Brain. Oct 2007;130(Pt 10). • Seizures are common. • CNS abnormalities are always present, including moderate-to-severe mental retardation. • Eye abnormalities are similar but more severe than those of Fukuyama CMD. • Cerebral changes are similar to those of Fukuyama CMD.
  • 68.
    Walker-Warburg syndrome  Mutationsin all 6 glycotransferases have resulted in this most severe form of congenital muscular dystrophy.  Most severe of all alpha dystroglycanopaties.  Eye abnormalities include microphthalmos, hypoplastic optic nerve, ocular colobomas, retinal detachment, cataracts, glaucoma, iris malformation, and corneal opacities, all of which lead to blindness.  Brain abnormalities include complete type II lissencephaly with agyria.
  • 69.
    HIERARCHY OF ORGANINVOLVEMENT IN ALPHA DYSTROGLYCANOPATHY CEREBRUM EYES PONS CEREBELLUM STRIATEDMUSCLE
  • 70.
    Rigid-spine syndrome withmuscular dystrophy  Autosomal recessive  Mutation in the selenoprotein N gene (SEPN1).  Presentation is at birth or within the first year of life  Scapular winging and facial and bulbar weakness are common.  Contractures usually develop at age 3-10 years.  Respiratory insufficiency is common and progressive  Muscle weakness is slowly progressive.  The cardiac system is usually normal.  Intelligence and brain MRIs are normal.
  • 71.
    Ullrich congenital musculardystrophy  Autosomal recessive (or more rarely dominant) disorder  Mutation in 1 of the 3 collagen type VI genes (COL6A1, COL6A2, COL6A3).  Typical features include presentation in the neonatal period  with hypotonia, kyphosis of the spine, proximal joint contractures, torticollis, and hip dislocation.  Distal joint hyperlaxity with a protruding calcaneus  Weakness involves distal more than proximal muscles.  Progressive disability, usually due to contractures, leads to loss of ambulation after 2-10 years.
  • 72.
     Respiratory insufficiencyinvariably develops in the first or second decade.  Facial dysmorphism is common and includes micrognathia, a round face with drooping of the lower lids, and prominent ears.  Skin changes can include follicular hyperkeratosis, keratosis pilaris, and keloids.  Intelligence and brain MRIs are normal.  Cardiac function is normal.
  • 73.
    UCMD: Report ofnine cases from India A Nalini, N Gayatri Neurology India 2009
  • 74.
    Muscle weakness,contractures,cogni tive decline, seizures CMD MEB WalkerWarburg Fukuyama CMD Eye involvement, brain malformations, raised CK Distal > proximal weakness, distal joint hyperlaxity, proximal contractures, skin changes Ullrich’s CMD Proximal> distal weakness RSMD Merosin def CMD
  • 75.
    Management  No specifictreatment is available for any of the congenital muscular dystrophies.  Aggressive supportive care is essential to preserve muscle activity, to allow for maximal functional ability, and to prolong the patient's life expectancy.  Management of pulmonary and cardiac problems.
  • 76.
  • 77.
    G tube implantation: Physiologicaland most acceptable way of feeding for long term
  • 78.
    Surgical Care • Orthopedicsurgery is often necessary in patients who live several years with their disease to prevent contractures and scoliosis Post scoliosis Surgery:
  • 79.
    Gene therapy  Agrinwhich binds to laminin and to α-drystroglycan might be able to functionally rescue the weakened muscle caused by LAMA2 mutations.  The Agrin transgene improved the general health, lifespan and locomotory activity of the mutant mice.  This study demonstrates the potential for gene therapy using non-homologous proteins that functionally compensate for gene mutation.
  • 80.
    Summary  Congenital myopathiesnot so uncommon in india, and an important diagnosis to be considered in a floppy infant  Muscle histopathology is the gold standard for diagnosis.  Of the congenital muscular dystrophies, only merosin deficiency and Ullrich’s CMD are reported from india.  Contractures, Brain involvement and dystrophic changes in muscle are the hallmark of CMD  Gene therapy in the coming years can bring in a definite solution to the problems.
  • 81.