[Prenatal genetic diagnosis for two Chinese families affected with oculocutaneous albinism type â…¡].

[oculocutaneous albinism]

To perform genotyping analysis and subsequent prenatal genetic diagnosis for two families affected with oculocutaneous albinism (OCA ).Direct sequencing of TYR and P genes was performed in two albino probands . Family members were screened for corresponding mutant alleles . Prenatal genetic diagnoses were performed at early pregnancy by chorionic villus sampling (CVS ) at mid-pregnancy through amniocentesis .No mutations were detected in the TYR gene in either probands , whereas 4 heterozygous mutations of the P gene were found , namely c .406 C >T , c .535 A >G , c .808 -2 A >G and c .2180 T >C , among which c .535 A >G and c .808 -2 A >G were novel . In the first round prenatal genetic testing , both fetuses were found to have the same genotypes as the probands . Both families had decided to terminate the pregnancy after genetic counseling . In the second round testing , neither of the fetuses was found to be affected by genotyping . The pregnancies continued and two healthy fetuses were born .OCA can be classified by genotyping , with which reliable prenatal diagnosis and feasible genetic counseling may be provided .