[Prenatal genetic diagnosis for two Chinese families affected with oculocutaneous albinism type Ⅱ].

OBJECTIVE

To perform genotyping analysis and subsequent prenatal genetic diagnosis for two families affected with oculocutaneous albinism (OCA).

METHODS

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.

RESULTS

No mutations were detected in the TYR gene in either probands, whereas 4 heterozygous mutations of the P gene were found, namely c.406C>T, c.535A>G, c.808-2A>G and c.2180T>C, among which c.535A>G and c.808-2A>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.

CONCLUSION

OCA can be classified by genotyping, with which reliable prenatal diagnosis and feasible genetic counseling may be provided.