Dupli
cations leading to fun
ctional diso
my of
chro
moso
me Xq28, in
cluding
m>MECP2m> as the
criti
cal dosage-sensitive gene, are asso
ciated with a distin
ct
clini
cal phenotype in
males,
chara
cterized by severe
mental retardation, infantile hypotonia, progressive neurologi
c i
mpair
ment, re
current infe
ctions, bladder dysfun
ction, and absent spee
ch.
Female patients with Xq duplications including MECP2 are rare. Only recently submicroscopic duplications of this region on Xq28 have been recognized in four females, and a triplication in a fifth, all in combination with random X-chromosome inactivation (XCI). Based on this small series, it was concluded that in females with m>MECP2m> duplication and random XCI, the typical symptoms of affected boys are not present. We present clinical and molecular data on a series of five females with an Xq28 duplication including the m>MECP2m> gene, both isolated and as the result of a translocation, and compare them with the previously reported cases of small duplications in females. The collected data indicate that the associated phenotype in females is distinct from males with similar duplications, but the clinical effects may be as severe as seen in males.