Prenatal diagnosis of oculocutaneous albinism type IV and discovery of a novel mutation

Objective To provide guidance for clinical genetic counseling and prenatal diagnosis of oculocutaneous albinism (OCA) in China. Methods PCR and automatic DNA sequencing were applied to obtain the genotypes of the patients and their parents in three Chinese albinism families. Prenatal gene diagnoses were performed at early pregnancy by chorionic villus sampling (CVS) or by amniocentesis at midpregnancy. Results The three patients were all OCA4, whose genotypes were G349R/c. 870delC, G349R/P419L, G349R/D160H, respectively. The three couples had been diagnosed as carriers. In family 1, the first fetus was diagnosed as affected. Termination of pregnancy was opted following genetic counseling. The second fetus (monozygotic twin) was heterozygous only with the paternal G349R mutation. The fetus in family 2 did not get either one of the two mutations. The fetus in family 3 was heterozygous only with the paternal G349R mutation. Conclusion This study detected three reported pathogenic mutations of the membrane associated transporter protein gene (MATP), including G349R, D160H and P419L, and identified a novel pathogenic mutation c. 870delC. The prenatal gene diagnosis of OCA4 will be important to prevent the birth of affected child. Key words: oculocutaneous albinism type Ⅳ;  MATP gene;  gene mutation;  prenatal diagnosis