[Klinefelter syndrome in 1993. Results of a multicenter study on 58 cases and review of the literature].

A retrospective multicenter study found 58 cases of Klinefelter syndrome of which 23 (39%) were diagnosed before puberty. Although as common as Down syndrome, Klinefelter syndrome is underdiagnosed and often recognized only in adulthood. Suggestive manifestations in infants, children, and teenagers include facial dysmorphism, micropenis, and delayed speech and should lead to examination of the karyotype. Early recognition of Klinefelter syndrome could be achieved by routinely measuring the size of the testes in school-boys aged 11 to 15 years and performing a karyotype in boys with a volume of less than 2 ml. Early psychological and educational support and testosterone replacement therapy initiated at onset of puberty may lead to improved social and academic outcomes.