AMYOPLASIA: AUTOSOMAL RECESSIVE INHERITANCE IN TWO FAMILIES

Abstract

Amyoplasia has been previously described as a sporadic congenital form of skeletal muscle dysplasia resulting in arthrogryposis. We presently follow two families in which amyoplasia is not sporadic but is probably inherited as an autosomal recessive trait. In the first family, a 31 year old gravida 5 parity 4 Hispanic mother delivered a female child via cesarean delivery at term. Salient features included arthrogryposis, decreased muscle bulk, decreased movements, bilaterally dislocated hips, moderate hirsutism, nevus flammeus of the forehead and a high arched palate. No central or peripheral nervous system abnormalities were demonstrable and muscle biopsy confirmed the diagnosis of amyoplasia. Family history revealed that the parents were first cousins and a sibling of the current patient died at four months of age with similar features. The sibling also failed to demonstrate any central or peripheral nervous system abnormalities and, on review, had a muscle biopsy consistent with the diagnosis of amyoplasia. The second family was referred for counseling after a four year old daughter with decreased muscle mass, arthrogryposis, minimal spontaneous movements, small mouth, long tapered fingers and toes and a nevus flammeus of the forehead was diagnosed as having amyoplasia. Family history revealed that the Hispanic parents were first cousins, once removed. Conclusion: Amyoplasia is a syndrome of heterogenous etiologies and, in ser lected populations, may be inherited as an autosomal recessive trait.