skip to main content

Trisomy 13 – Patau — RACP Paediatrics MCQ

Instant feedback + full explanation. One question, done properly.

ModerateGeneticsTrisomy 13 – PatauRACP Paediatrics

A newborn has holoprosencephaly, midline cleft lip and palate, polydactyly, and microphthalmia. There is a cutis aplasia on the scalp. CHD (ASD) is present. Karyotype shows trisomy. What is the most likely chromosomal abnormality?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: A — Patau syndrome (trisomy 13)

Holoprosencephaly, midline facial defects (cleft lip/palate), polydactyly, microphthalmia, cutis aplasia, and CHD is trisomy 13 (Patau syndrome). Median survival is 7-10 days. It is the third most common autosomal trisomy compatible with live birth (after trisomy 21 and 18).

Reference: RACP Paediatric Curriculum – Genetics; RCH Melbourne – 2023