Idiopathic Fanconi syndrome in a family. Part I. Clinical aspects.

Fanconi syndrome is a rare cause of rickets in children. Only six families with Fanconi syndrome following an autosomal dominant pattern of inheritance have been reported. In this report, the results of clinical studies performed in three generations of a family of 39 members with autosomal dominant Fanconi syndrome are presented. Twenty-one members of this family provided blood and urine for biochemical evaluation. Many family members have one or more tubular reabsorptive abnormalities; however, the complete Fanconi syndrome was not present in most members. Three children with the complete syndrome all occur in the last generation. When the characteristic features of this family were compared with those of previously reported families with autosomal dominant Fanconi syndrome, several differences became apparent. Two serious manifestations, diabetes mellitus and renal failure, which occur in previous reports did not occur in this family. This report provides information on apparently the largest number of affected individuals in a single family with Fanconi syndrome. In addition, variable expressivity of tubular reabsorptive defects in a family with Fanconi syndrome has never been reported.