OBJECTIVE: To evaluate the feasibility of genetic analysis of tyrosinase gene 
(TYR) in oculocutaneous albinism type I (OCA1). Mutation analysis and prenatal 
genetic diagnosis of TYR gene for seven pedigrees with OCA1 were performed.
METHODS: PCR was used to amplify the exons, exon-intron boundaries and promoter 
of the TYR gene in the probands and/or their parents. The products were further 
analyzed by direct sequencing. Prenatal genetic diagnoses were performed by 
chorionic villus sampling after the genotypes of the probands or their parents 
were determined.
RESULTS: Compound heterozygous mutations were detected in all pedigrees, which 
included 9 mutations, namely R76Q, c.232insGGG, R116X, R278X, R299H, 
c.929-930insC, IVS2-11delTT, Q399X and W400L. Among these, R76Q and Q399X were 
identified for the first time. Seven families have requested prenatal diagnoses. 
One fetus was detected with double mutations of TYR gene, and the parents have 
decided to have therapeutic abortion. Two fetuses did not carry the mutations 
identified in the probands, whilst other four fetuses were carriers of 
heterozygous mutations. Six families decided to carry on with the pregnancies. 
And the neonates did not show any symptoms of OCA after birth.
CONCLUSION: Direct sequencing of the TYR gene is helpful for genetic counseling, 
prenatal diagnosis and carriers screening of OCA1.