Genotypes:
(1) 47 XXY
(2) mosaics with 46XY and 47 XXY
(3) 48 XXXY
Clinical features:
(1) small testes with a firm consistency due to testicular fibrosis
(2) decreased spermatogenesis with infertility
(3) gynecomastia
(4) increased armspan, being greater than height by 2 cm or more
(5) increased height (postpubertal height > 184 cm) due to increased leg length, with the length from hip to soles at least 2 inches greater than the length from head to hips
Laboratory Findings:
(1) increased gonadotropins (LH, FSH)
(2) decreased free testosterone (total testosterone may be normal)
(3) decreased inhibin B in serum
(4) Barr bodies in nuclei on buccal cell smears (except in mosaics)
Additional findings:
(1) decreased facial and pubic hair
(2) decreased penis size
(3) learning disabilities
(4) anxiety and neuroses
(5) osteoporosis
(6) adult onset diabetes mellitus
(7) taurodontism with teeth having a thinning of the surface and enlargement of the pulp
(8) weakness and fatigue
(9) erectile dysfunction
Genetic testing:
(1) peripheral blood karyotyping to detect an extra X chromosome
(2) if the peripheral blood karyotyping is negative and mosaicism is suspected, then testicular biopsy with karyotyping may be warranted.
