ALTERNATE NAMES

Classic CMD LAMA2; Congenital Muscular Dystrophy with Laminin-Alpha-2 Deficiency; LAMA2; Laminin Alpha-2; LAMM; MDC1A; MDCMD; Merosin Deficient CMD; Merosin Positive CMD; Muscular Dystrophy Congenital

DESCRIPTION

Merosin deficient congenital muscular dystrophy (CMD) is a rare and highly severe type of muscular dystrophy. Mutations in the LAMA2 gene have been identified as the cause of congenital merosin-deficient CMD. Children with this form of CMD lack all or part of the muscle protein merosin, or laminin.

The condition initially presents around six months with extreme weakness and contractures, resulting in failure to ambulate. Breathing problems may require treatment with tracheotomy. Most infants have normal intelligence, but intellectual disability and epilepsy associated with merosin-deficient CMD have been reported. The severity of this condition is determined by the amount of the merosin protein that the child has.

DIAGNOSTIC TESTING, PHYSICAL FINDINGS, AND ICD-9-CM/ICD-10-CM CODING

Diagnostic testing: Testing includes:

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  Magnetic resonance imaging (MRI) scan of the brain;.

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  Serum creatine kinase (CK) concentration;

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  Muscle biopsy;

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  Immunostaining of muscle; and

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  Genetic testing.

Physical findings: Physical symptoms include:

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  Muscle weakness (hypotonia);

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  Poor feeding;

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  Weak cry;

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  Breathing problems;

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  Congenital hip dislocation;

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  Scoliosis; and

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  Seizures.

ICD-9: 359.0

ICD-10: G71.09

PROGRESSION

Prognosis is poor. Most children affected by merosin-deficient CMD do not survive into adolescence.

TREATMENT

There is currently no cure for merosin-deficient CMD. Treatment is symptomatic and supportive. Treatment approaches include physiotherapy to reduce contracture and arthrodesis to limit deformation. Ventilatory support and tracheotomy, when necessary, have contributed to a marked increase of the life expectancy for the most severely affected patients.

SUGGESTED PROGRAMMATIC ASSESSMENT*

Suggested MER for Evaluation: Clinical examination including a description of physical findings, family history, genetic testing, electromyography or nerve conduction tests, and blood and enzyme tests.

Suggested Listings for Evaluation:

DETERMINATION

LISTING

REMARKS

Meets

110.08 B

111.13

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