Mutation analysis of the phenylalanine hydroxylase gene in Azerbaijani population, a report from West Azerbaijan province of Iran

Phenylketonuria (PKU) is a genetic inborn error of phenylalanine (Phe) metabolism
resulting from insufficiency in the hepatic enzyme, phenylalanine hydroxylase (PAH), which leads to
elevated levels of Phe in the blood. The present study was carried out for mutation analysis of the PAH
gene in West Azerbaijan province of Iran.
Materials and Methods: A total of 218 alleles from 40 PKU families were studied using restriction
fragment length polymorphism‐polymerase chain reaction (RFLP‐PCR) method.
Results: The frequencies of IVS10‐11, S67P, R261Q, R252W, IVS11nt‐1 g>c, R408Q, and Q232Q
mutations were 28(35), 17(21.25), 15(18.75), 3(3.75), 3(3.75), 2(2.5), and 1(1.25), in cases group, and
51(23.4), 31(14.2), 27(12.4), 6(2.75), 6(2.75), 4(1.83), and 2(0.92) in total group, respectively. The
mutations of R243Q, 364delG, L333F, 261X, I65T, and R408W were not detected in our samples.
Conclusion: It can be concluded that the IVS10‐11 mutation has the highest frequency in the tested
population. To our knowledge, this report is the first in its own kind and provides better
understanding of the genetic heterogeneity, the origin and distributions of PAH mutations in West
Azerbaijan province of Iran.