Autosomal recessive inheritance of metaphyseal dysplasia (Pyle disease).

Two young adults with Pyle disease have been investigated in a large Afrikaner kindred in South Africa. Consanguinity was present in the family, and it is likely that the condition was inherited as an autosomal recessive. This contention is supported by the radiographic demonstration of minor degrees of widening of the distal femora in obligatory and potentially heterozygous relatives. Apart from genu valgus of moderate degree, the patients enjoyed good health and their gross radiographic skeletal abnormalities contrasted with the innocuous clinical presentation. Differentiation of Pyle disease from the autosomal dominant and autosomal recessive forms of cranio-metaphyseal dysplasia is of prognostic importance in view of the potentially serious complications in these latter disorders.