The association of facial anomalies, short stature, hypogonadism, and gait ataxia in a mentally retarded boy should prompt molecular analyses of the CUL4B gene.
CUL4B gene mutation can cause intelligence deficiency 15, a syndromic form of X-linked mental retardation characterized by severe intellectual deficit associated with short stature, craniofacial dysmorphism, speech delay and impairment, tremor and gait ataxia.