<prompt> Mr. and Mrs. Annadurai have a 2 month old baby suffering from Downs syndrome. Karyotype of Mrs. Annadurai shows translocation variety of Down syndrome. Which of the following investigations will you advise to the parents before the next pregnancy?Triple testa-fetoproteinKaryotypingb-human chorionic gonadotropin hCG  <response>: Trisomy 21 may arise fromNon-disjunction of chromosome 21:Most common mode 95Risk of recurrence is 1 Invasive prenatal diagnosis is indicatedPaternal chromosome study not neededTranslocation or mosaicismPaternal chromosome study is indicatedRisk of recurrence is highRef: Harrisons 18e p510, 511, Williams 21e p944, Ghai 5e p478, 479 