TURNER'S SYNDROME (TS)
The essential facts:
A 'syndrome' is a group of associated physical characteristics and in
1938 Dr. Henry Turner first described girls with the features of the condition
named after him.
Cause:
The sex of babies is determined at conception when an egg (ovum) is
fertilised by a sperm carrying either an X (female) or a Y (male) chromosome.
Early in development during division of the cells of the fetus a sex chromosome
is occasionally lost. When this happens the fetus usually dies and is miscarried
but about 1 in 2500 female fetuses survives with some or all cells missing
an X chromosome (or sometimes carrying one abnormal X). For reasons not
yet understood such fetuses develop the features of TS. There is no increased
risk to later children of the same parents.
Major features:
The two fundamental features of TS are:
1. Short stature. Babies with TS tend to be small at birth, growth through
childhood is slow and there is no pubertal growth spurt. The average height
of fully grown women with TS is 143cm (4ft8in) but there is a wide range
from 130cm (4ft3in) to 157cm (5ft2in), in general the taller the parents
the taller the daughter. Treatment with growth hormone is now available
but at best can probably add only about 5-10cm (2 to 4 inches) to the final
height.
2. Ovarian dysgenesis (malformation). In most (but not all) girls with
TS the ovaries are represented by small streaks of tissue which are unable
to produce appropriate amounts of female hormone (oestrogen) or ova. Replacement
of oestrogen is therefore needed at puberty and for most affected girls
infertility is inevitable. The womb and other internal and external sexual
organs are normal and girls with TS have successfully carried donated and
fertilised ova.
Other features:
There are a number of other features of TS which may or may not be present,
most are of relatively minor importance:
1. Characteristic facial features and ears, a 'wide' body build, 'webbing'
of the neck, a broad chest with widely-spaced nipples, slight angulation
of the outstretched arms at the elbows, small hands and feet which may
be puffy in infancy, narrow finger and toenails and multiple small dark
birthmarks ('moles').
2. Abnormalities of internal organs may be, but usually are not, present.
These include a malformed valve at the junction of the heart with the major
artery to the body (the aorta) or narrowing (coarctation) of this artery,
abnormally formed kidneys and thinning (osteoporosis) of the bones.
3. Intelligence is normal but some affected girls do have particular
problems with spatial tasks and/or maths and this can make schoolwork difficult.
Parents should keep in mind the tendency of teachers and others to expect
less of all small children!
4. In early childhood most girls with TS are prone to recurrent attacks
of middle ear infection (otitis media) and 'glue ear', prompt treatment
is needed to preserve hearing and aeration tubes (grommets) may be indicated.
Any suspicion of hearing loss should be investigated. Minor eye problems
including refractive errors and squints are common.
5. There is a tendency to develop high blood pressure so this should
be checked from time to time. There is also a tendency for the thyroid
gland to become underactive, this is easily checked and if necessary treated
with thyroxine tablets.
Treatment:
If growth hormone treatment is to be tried it is probably desirable
to start at an early age, around five years if possible, and to continue
until growth is complete. Daily injections are obviously a trial for children
but are generally well tolerated. Current preparations have an excellent
safety record after 10 years use. Oestrogen replacement should be started
at the time of normal puberty, around 11 years, with low but increasing
doses to mimic the normal process of development. A cyclical oestrogen/progesterone
preparation (contraceptive Pill formulations are suitable for this) is
given later to induce a monthly 'period' which is necessary to allow shedding
of the lining of the womb. Replacement should be continued indefinitely
to maintain physical and psychological femininity.
Conclusion:
It may be difficult for parents to decide when is the best time to tell
their daughter the facts about TS but experience suggests that in general
the earlier the better. They will of course also wish to emphasise that
girls with TS can expect to live a normal life span in good health, to
have normal job and marriage opportunities and normal sexual inclination
and function. Affected girls are often particularly maternal by nature
and if reproduction is impossible many take great joy in adopting and mothering
children. |
