[48,XXYY syndrome in a boy with essential tremor. Comparison with 120 cases from the literature].

We report on a 14 year-old boy with 48,XXYY karyotype, presenting with essential tremor and a slight retardation of psychomotor development. In contrast to other cases with 48,XXYY syndrome, this pubertal patient has testicles of normal size, has small stature and shows no behavioural disturbances. We compared our patient with 120 other published cases.