Abstract
Large families with congenital muscular dystrophy are rare. We report a clinical,
histopathological, immunocytochemical, electrophysiological, radiological and genetic
study of 10 cases affected by "pure" CMD belonging to two generations of a large inbred
Palestinian family. The disease showed autosomal recessive inheritance. All patients
had generalised muscular weakness and hypotonia at birth without arthrogryposis. They
had a relatively benign clinical course with stabilisation of the clinical picture
at different ages and at variable degrees of severity. The pattern of muscle weakness
and wasting was more marked in the proximal upper limb-girdle and trunk muscles. Lower
limb muscles were more mildly involved. Serum CK was normal or moderately increased.
All patients had normal intelligence, normal computed tomography (CT) scans of the
brain and normal somatosensory evoked potentials (SEP).
Electromyography (EMG) and muscle biopsy showed morphological changes compatible with
muscular dystrophy. Immunocytochemistry for dystrophin, laminin α2 of merosin, and
for α, β, γ sarcoglycans was normal. Linkage analysis excluded all the known loci
for CMD, including laminin α2 on chromosome 6q2, the Fukuyama congenital muscular dystrophy locus on 9q3, the integrin α7 locus on chromosome 12q13
and the recently identified locus on 1p35-36.
The family we present is clinically and genetically distinct from the already mapped
forms of congenital muscular dystrophy. Genetic studies are in progress to localise
the gene responsible for this condition.
Key words
Merosin-positive - pure congenital muscular dystrophy - Hypotonia
