Studies on R111 homozygous mutation of PAH gene in Xinjiang Uigur family.

Objective:To identify the gene mutation of phenylalanine hydroxylase(PAH) in Xinjiang Uigur family with phenylketonuria(PKU),and investigate the disposition and frequency of the mutant gene.Methods:Single strand conformation polymorphism(SSCP) essay and sequence analysis of the PCR product were used to ascertain the gene mutation of phenylalanine hydroxylase(PAH).Results:Single strand conformation polymorphism(SSCP) essay was used to screen exons 3,exons 5,exons 6,exons 7,exons 11 and exons 12 of aeger and his parents.There are differences in SSCP electrophoresis strips between the aeger and normal,also between the aeger and his parents.It was demonstrated from sequencing result that C→T mutation has happened on the site 331 of the aeger′s PAH cDNA.Unlike their child′s R111 homozygote mutation,the aeger′s parents are heterozygotes,although they have the same site mutation.Conclusion:It is the first time that R111 homozygote mutation was found in minority ethnic group internal.According to the PKU ratio of Uigur group and Han group and the probability of homozygote,altofrequent R111 gene mutation should happened in Uigur group.After aggregate analysis of the disposition and the frequency of the R111 mutatant gene in both here and abroad,it is concluded that the peak of R111 mutatant gene is in North China,and it is also presumed that the north area around Tianjin is the founder of R111 mutatant gene.