<prompt> Mr. and Mrs. Mehtha have a 2 month old child with Downs syndrome. Karyotype of Mrs Mehtha shows translocation variety of Down syndrome. Which of the following investigations will you advise to the parents before the next pregnancy?Triple testOC - fetoproteinKaryotypingP - human chorionic gonadotropin hCG  <response>: Karyotyping of Mrs. Annadurai has already been done and a translocation variety of Downs detected. Risk of recurrence however does not depend on mothers karyotype alone, but it also depends on the fathers karyotype. Fathers karyotyping is therefore the test of choice prior to next pregnancy to determine the recurrent risk of having another child with Downs syndrome. Ref: In-Vitro Feilization By Kay Elder, 3rd Edition, Page 243 ; Textbook of Obstetrics By D.C.Dutta, 6th Edition, Page 107 