Table 1 Chronological evolution of clinical, histological and hormonal parameters of Klinefelter variants. Eunuchoid morphology and gynecomastia are absent in 49,XXXXY karyotype

FSH

N

N

++

++++

LH

N

N

+

+++

T

-

N or -

+

- - -

E2

N

++

++

++

Inhibin B

N

N

- -

- - - -

AMH

N

N

- -

- - -

INSL3

N

N

- -

- - - -

Germ cells

Degeneration begun

Progressive degeneration

Accelerated degeneration in early puberty

- - - -

Presence of spermatogonia only

Clinical

Cryptorchidism

Subnormal Testis weight

Eunuchoid (+/−)

Gynecomastia (+/−)

Hypogonadism

Testis atrophy