An unusual case of congenital muscular dystrophy with normal serum CK level, external ophtalmoplegia, and white matter changes on brain MRI

Congenital muscular dystrophies

Congenital muscular dystrophies (CMDs) are a heterogeneous group of disorders characterized by muscle weakness from birth, or shortly after, and variable clinical manifestations of the eye and central nervous system. Some of these disorders are fatal in the first years of life, whereas others have a milder course, with survival into adulthood. The CMDs were initially classified by clinical features and country of origin; however, with new molecular techniques it is now possible to classify these patients better. More than 10 genes have been identified to date that cause forms of CMD. However, even with current molecular diagnostic techniques, only approximately 25-50% of patients with CMD have an identifiable genetic mutation. In addition, some phenotypic classifications have been attempted. There is significant overlap between the phenotypic and molecular classifications, making diagnosis within this heterogeneous group of disorders difficult.

Leukodystrophies and other genetic metabolic leukoencephalopathies in children and adults

Abnormalities of CNS white matter are frequently detected in patients with neurological disorders when MRI studies are performed. Among the many causes of such abnormalities, a large group of rare genetic diseases poses considerable diagnostic problems. Here we present a compilation of genetic leukoencephalopathies to consider when one is confronted with white matter disease of possibly genetic origin. The table contains essentials such as age at onset of symptoms, clinical and MRI characteristics, basic defect, and useful diagnostic studies. The table serves as a diagnostic check list.

Congenital muscular dystrophy. Part I: a review of phenotypical and diagnostic aspects

The congenital muscular dystrophies (CMDs) are a group of genetically and clinically heterogeneous hereditary myopathies with preferentially autosomal recessive inheritance, that are characterized by congenital hypotonia, delayed motor development and early onset of progressive muscle weakness associated with dystrophic pattern on muscle biopsy. The clinical course is broadly variable and can comprise the involvement of the brain and eyes. From 1994, a great development in the knowledge of the molecular basis has occurred and the classification of CMDs has to be continuously up dated. We initially present the main clinical and diagnostic data concerning the CMDs related to changes in the complex dystrophin-associated glycoproteins-extracellular matrix: CMD with merosin deficiency (CMD1A), collagen VI related CMDs (Ullrich CMD and Bethlem myopathy), CMDs with abnormal glycosylation of alpha-dystroglycan (Fukuyama CMD, Muscle-eye-brain disease, Walker-Warburg syndrome, CMD1C, CMD1D), and the much rarer CMD with integrin deficiency. Finally, we present other forms of CMDs not related with the dystrophin/glycoproteins/extracellular matrix complex (rigid spine syndrome, CMD1B, CMD with lamin A/C deficiency), and some apparently specific clinical forms not yet associated with a known molecular mechanism. The second part of this review concerning the pathogenesis and therapeutic perspectives of the different subtypes of CMD will be described in a next number.