Patau Syndrome (Trisomy 13)
Patau Syndrome (trisomy 13) is a chromosomal defect caused by the presence of an extra chromosome 13. Affected patients typically have severe intellectual disability as well as physical abnormalities in various body locations. Notable findings include cutis aplasia, gastroschisis & omphalocele, holoprosencephaly (microcephaly and cyclopia), microphthalmia, rocker-bottom feet, cleft palate, and polydactyly. Patau syndrome patients also may present with congenital heart defects, commonly ASD and VSD. First trimester labs are remarkable for decreased PAPP-A and β-hCG, which may help suggest a diagnosis of Patau syndrome.