AKT · Child health/Genetic syndromeslow yield

Edwards & Patau syndromes

Trisomy 18 (Edwards) · Trisomy 13 (Patau)

Overview

The two other autosomal trisomies after Down syndrome — both far more severe, with high perinatal mortality. High-yield for their distinguishing features and for antenatal screening.

Recognise

Edwards (T18): rocker-bottom feet, overlapping/clenched fingers, micrognathia, low birth weight, cardiac/renal defects
Patau (T13): midline defects — cleft lip/palate, holoprosencephaly, microcephaly, POLYDACTYLY, cardiac defects
Both: profound developmental impairment; most die in infancy

Red flags

Antenatal screen-positive pattern; cardiac/structural anomalies on scan

Differentials & how to tell them apart

Down syndromecommonest, longer survival; flat facies, single palmar crease, AVSD, duodenal atresia

Patau (T13)polydactyly, cleft lip/palate, holoprosencephaly

Edwards (T18)rocker-bottom feet, overlapping fingers, micrognathia

Investigations

Antenatal combined/quadruple test + NIPT; diagnostic karyotype/array (CVS/amniocentesis or postnatal); echocardiogram, renal USS.

Management

Genetic confirmation + MDT; care often palliative given prognosis

1Confirm with karyotype/array; full anomaly assessment; honest prognostic counselling with the family.Gate: Most affected infants die within the first year → care is frequently palliative and family-centred
2Genetic counselling regarding recurrence; antenatal screening in future pregnancies.

Supportive / palliative — MDT, often comfort-focused given prognosis

Key points

Edwards = trisomy 18, rocker-bottom feet + overlapping fingers; Patau = trisomy 13, Polydactyly + cleft/holoprosencephaly. Both rarer and far more severe than Down.

Monitor & prognosis

Symptom-focused; family support.

Poor — high perinatal/infant mortality.

Source: Clinical genetics; UK fetal anomaly screening