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.
The association of facial anomalies, short stature, hypogonadism, and gait ataxia in a mentally retarded boy should prompt molecular analyses of the CUL4B gene.