Patau Syndrome (Trisomy 13)


Patau Syndrome, also known as Trisomy 13, is a chromosomal defect caused by possessing three copies of chromosome 13.

Affected patients typically have severe intellectual disability (developmental delay), as well as various physical abnormalities. Notable findings include cutis aplasia, gastroschisis/omphalocele, holoprosencephaly (microcephaly and cyclopia), microphthalmia, rocker-bottom feet, cleft palate, and polydactyly. Patients also may present with congenital heart defects (commonly ASD & VSD). First trimester labs in pregnancy are remarkable for decreased PAPP-A and β-hCG, which may suggest a diagnosis of Patau syndrome.

Find Patau Syndrome and other Chromosomal Abnormalities among Pixorize's visual mnemonics for the USMLE Step 1 and NBME Shelf Exams.