Tall stature and eunuchoid body proportions characterize patients with
47,XXY Klinefelter syndrome, whereas patients with 45,X Turner syndrome are
characterized by impaired growth. Growth is relatively well characterized in
these two syndromes, while few studies describe the growth of patients with
higher grade sex chromosome aneuploidies. It has been proposed that tall stature
in sex chromosome aneuploidy is related to an overexpression of
SHOX, although the copy number of SHOX has
not been evaluated in previous studies. Our aims were therefore: (1) to assess
stature in 305 patients with sex chromosome aneuploidy and (2) to determine the
number of SHOX copies in a subgroup of these patients (n
=255) these patients and 74 healthy controls. Median height standard
deviation scores in 46,XX males (n =6) were −1.2 (−2.8
to 0.3), +0.9 (−2.2 to + 4.6) in 47,XXY (n
=129), +1.3 (−1.8 to +4.9) in 47,XYY (n
=44), +1.1 (−1.9 to +3.4) in 48,XXYY (n
=45), +1.8 (−2.0 to +3.2) in 48,XXXY (n
=9), and −1.8 (−4.2 to −0.1) in 49,XXXXY (n
=10). Median height standard deviation scores in patients with 45,X (n
=6) were −2.6 (−4.1 to −1.6), +0.7
(−0.9 to +3.2) in 47,XXX (n =−40), −0.6
(−1.9 to +2.1) in 48,XXXX (n =13), and −1.0
(−3.5 to −0.8) in 49,XXXXX (n =3). Height increased with
an increasing number of extra X or Y chromosomes, except in males with five, and
in females with four or five sex chromosomes, consistent with a nonlinear effect
on height.
