Transposition of external genitalia and associated malformations.

We report three Egyptian boys from three different families born with penoscrotal transposition (PST). None of them fell into categories of known syndromes, associations, sequences or chromosome disorders. Other malformations observed included renal, genital, cardiovascular and limb defects. Although the occurrence of most reported cases of PST are sporadic, three families with affected sibs have been reported in the literature where parental consanguinity was not specified. Parental consanguinity is present in two of our three cases with young parental age suggesting the possibility of an autosomal recessive pattern of inheritance. A history of maternal hormonal treatment early in pregnancy in one of our cases may suggest a role of teratogenic agents. We conclude that PST may represent only a part of a wide spectrum of anomalies resulting from a major insult occurring during early embryonic development and is of heterogeneous etiology.