Prenatal diagnosis of oculocutaneous albinism two mutations located at thesame allele

A pregnant woman accepted amniocentesis on account of the previous birth of type 1 oculocutaneous albinism (OCA1). PCR revealed that the fetus had two mutations (862delTT, Arg 299His). The father had one missense mutation (Ar g 299Ser) and the mother had the same mutations as the fetus. Two mutations of the fetus located at the same allele were suspected. Postpartal follow- up confirmed his carrier status. For recessive disorders, faced with a fetu s with two mutations. the importance of performing segregation analysis of mutation on both parents is emphasized. This could exclude two mutations lo cated at the same allele and prevent the unnecessary termination of a fetus with carrier status. Copyright (C) 2001 John Wiley & Sons, Ltd.