<prompt> The Simian crease is not seen in ___Down syndromeTrisomy 13Cri du chat syndromeCystic Fibrosis  <response>: Simian crease single transverse palmar crease is not seen in cystic fibrosis. Simian crease is seen in : Down;s syndrome Fetal alcohol sydrome Trisomy 13 Cri du chat syndrome Ref: Online resources 