Cryptorchidism in mental retardation.

We surveyed 148 institutionalized male subjects to study the prevalence of cryptorchidism among mentally retarded individuals. Of the patients 121 (81.7 per cent) were profoundly (intelligence quotient 19 or less), 21 severely (20 to 35), 5 moderately (36 to 51) and 1 mildly (65) retarded. Patient age ranged from 1 to 36 years (mean 13.6 means). According to the etiology of the mental retardation the cases were classified into 6 categories: chromosomal aberrations, single gene disorders, polygenic conditions, teratogen-induced anomalies, perinatal/postnatal injuries and idiopathic mental retardation. Cryptorchidism was found in 44 individuals (39.7 per cent), and was bilateral 3.4 times more often than unilateral. Cerebral palsy occurred in 88 patients. There were 36 patients with cryptorchidism and cerebral palsy, representing 41 per cent of the patients with cerebral palsy and 81.8 per cent of the cryptorchid group (p equals 0.0006). Among the noncryptorchid male subjects 52 (50 per cent) had cerebral palsy. Epilepsy also was more frequent in the cryptorchid group (p equals 0.0333). The cryptorchid and noncryptorchid groups did not show a significant difference in the etiology of mental retardation except in the perinatal/postnatal category in which cryptorchidism was more frequent (p equals 0.025), and in the polygenic category in which all 9 patients were noncryptorchid. This study shows a high prevalence of cryptorchidism in individuals with profound and severe mental retardation, and particularly in those having cerebral palsy.