<prompt> All of the following are true statements about Down syndrome, except:Most common inheritable cause of mental retardationIn quadruple test, Inhibin-A level is reducedMost common cause is meiotic non-disjunctionIn triple test AFP , estriol , hcG  <response>: ANTENATAL SCREENING FOR DOWN SYNDROME: TRIPLE TEST b-hCG Maternal Serum Alpha fetoprotein MSAFP Unconjugated Estriol uE3 QUADRUPLE TEST b-hCG Maternal Serum Alpha fetoprotein MSAFP Unconjugated Estriol uE3 Dimeric Inhibin-A OTHER OPTIONS Down syndrome is most common inheritable cause of mental retardation- true Most common cause of Down syndrome is meiotic non-disjunction, followed by Robesonian translocation- true 