Familial dwarfism with high IR-GH: report of two affected sibs with genetic and epidemiologic considerations.

Two sibs with high serum IR-GH dwarfism, born to first-cousin parents are described. Genetic analysis based upon 25 reported informative kindreds indicates that the condition has an autosomal recessive pattern of inheritance. Population evaluation and epidemiology of the affected subjects suggest that mutation rates of the gene determining the disease in non-Jewish populations could be as rare as 3.2 x 10(-5). However, its prevalence must be exceptionally high among endogamous Oriental Jewish groups derived from a common gene pool in historical times.