Clinical variation within sibships in Fukuyama-type congenital muscular dystrophy

A family in which three siblings were affected with severe cerebral malformations in association with ocular anomalies and muscle disease is reported. One sibling was diagnosed as having Fukuyama type congenital muscular dystrophy (FCMD) because he showed severe hypotonia with dystrophic findings on a muscle biopsy in addition to pachygyria on CT. At the age of 3 years, retinal detachment developed in both eyes. Another sibling exhibited at birth such characteristic features as pachygyria, cephalocele, hydrocephalus, retinal detachment in both eyes, elevated serum creatine kinase activity and arthrogryposis multiplex congenita. We consider these findings to be more consistent with Walker-Warburg syndrome (WWS) than with FCMD. Anencephaly found in the third sibling was regarded as WWS with extreme brain abnormality. The appearance of two syndromes (FCMD and WWS) in the three members of the same family suggests that these syndromes could be allelic with variable phenotypes.