Down's Syndrome

Dr Katie BennerVTS 1 in paediatrics

Definition

In 1887 Landon-Down described a syndrome of physical anomalies and mental handicap

Was previously known as “Mongolism”, now known as Down's syndrome or trisomy 21

Commonest of the chromosomal disorders and major cause of mental retardation

Incidence increases with maternal age

Clinical Features

Brachcephaly

maximal breadth of the skull in the coronal plain is more than 80% of the length in the sagittal plain

Short neck Epicanthic folds

Inward down - mongoloid - slant to the eyes Brushfield spots on the iris

almond shaped eyes small simple ears, which may be low set flat nasal bridge

protruding tongue, mouth hanging open narrow high arched palate

Associations

duodenal atresia (10%) Hirschsprung's disease (3%) other intestinal atresias Up to 40% have congenital heart disease: atrioventricular canal - the most common ventricular septal defect patent ductus arteriosus atrial septal defect - ostium primum (40%) tetralogy of Fallot

Management

Support for family Referral to MDT Referral to relevant specialists if complications

arise

Prognosis

90% live to 5 years Remainder die of congenital heart disease,

Hirschprung's and infection

Antenatal issues

All pregnant women should be offered screening (but it is their choice to decline)

From 10+0 to 20+0 weeks 2 different tests depending on when woman

presents If up to 14+1 gets triple test hCG, PAPP-A and

nuchal translucency If 14+2 to 20+0 gets hCG, AFP, uE3, inhibin A

Maternal risk

Woman's age (years)

Risk as a ratio%RiskBelow 20 1:16000.06720 1:15000.06630 1:800 0.12535 1:270 0.3740 1:100 1.045 and over 1.50 and greater 2.0