Retardo mental ligado al sexo. Presencia y ausencia de X frágil

Abstract

In three non related families we evaluated 15 patients with a similar clinical picture consisting of mental retardation, macroorchidism and minor anomalies. This picture showed a sex linked pattern of inheritance. In two families a fragility of the X chromosome at the band q27 was evident. In the third family it mas impossible to demostrate the X fragility, and it is clear that the disease was transmitted by a male. The phenotypic, cytogenetic, and psychological findigs are presented. Some aspects related to this form of sex-linked mental retardation are discussed as welas the as the transmission by a normal male in the two types of families: those with and those without the fragil X.