All of the following are true statements about Down syndrome, except:

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