Turner syndrome

The incidence of Turner syndrome in liveborn female
infants is 1 in 2500. Phenotypic abnormalities vary considerably
but are usually mild. In some infants the only detectable
abnormality is lymphoedema of the hands and feet. The most
consistent features of the syndrome are short stature and
infertility from streak gonads, but neck webbing, broad chest,
cubitus valgus, coarctation of the aorta, renal anomalies and
visual problems may also occur. Intelligence is usually within
the normal range, but a few girls have educational or
behavioural problems. Associations with autoimmune
thyroiditis, hypertension, obesity and non-insulin dependent
diabetes have been reported. Growth can be stimulated with
androgens or growth hormone, and oestrogen replacement
treatment is necessary for pubertal development. A proportion
of girls with Turner syndrome have a mosaic 46XX/45X
karyotype and some of these have normal gonadal
development and are fertile, although they have an increased
risk of early miscarriage and of premature ovarian failure.
Other X chromosomal abnormalities including deletions or
rearrangements can also result in Turner syndrome.