Condition	HCG	PAPP-A	AFP	Inhibin A	Nuchal translucency
Trisomy 21	↑	↓	↓	↑	↑
Trisomy 18	↓	↓	↓	normal	↑↑
Trisomy 13	↓	↓	normal	normal	↑

Down syndrome

Edwards syndrome

Rocker-bottom feet can also be found in Patau syndrome.

Patau syndrome