Page 524 - Medicine and Surgery

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520 Chapter 14: Genetic syndromes

Clinical features increase in incidence with advancing maternal age. Most
Tall, with long arms and legs, hypogonadism, female pu- cases of Turner syndrome spontaneously abort during
bic hair profile, high-pitched voice, reduced facial and pregnancy.
body hair. Other features that may be present include
gynaecomastia. There is greatly reduced fertility, slight Clinical features
but significant reduction in IQ. During pregnancy there may be generalised hydrops
or localised swelling on ultrasound due to late mat-
Investigations uration of the lymphatic system. Intrauterine growth
Karyotype analysis. retardation is common.
Neonates are phenotypically female, neck webbing,

Management puffy hands, low posterior hairline, large carrying
Testosterone replacement should be given during ado- angles (cubitus valgus), wide spaced nipples, and
lescence for psychosexual development and prevention carpal/pedal oedema.
of osteoporosis. Adults present with infantile genitalia, short stature
(<150cm),widespacednipples,neckwebbing,micro-
gnathia and prominent ears, wide carrying angle.
Turner syndrome
Increased frequency of renal (horseshoe kidney) and
Definition cardiovascular anomalies (coarctation of aorta) plus
Loss of a sex chromosome resulting in a 45,XO genotype. mild mental retardation in ∼10%. As there is nor-
mally only one copy of the X chromosome, females
Incidence suffer from X linked recessive conditions such as
1in 5000 live births. haemophilia.
Usually normal intelligence and life expectancy, but

Age deficient spatial perception, perceptual motor organ-
Congenital. isation or fine motor execution.

Sex Investigations
Phenotypically female. Genetic karyotyping will confirm the clinical diagnosis.

Aetiology/pathophysiology Management
The commonest underlying karyotype is 45,X; how- Growth hormone in childhood and oestrogen at puberty
ever, many females are mosaics: 45,X/46,XY (other mo- allows better growth and the development of secondary
saics include 45,X/47,XXX or 45,X/46,XY). There is no sexual characteristics but has no effect on fertility.