PREVALENCE OF PAH MUTATIONS IN GEORGIAN PKU PATIENTS COMPARED TO MOST FREQUENT PAH MUTATIONS IN EUROPEAN POPULATIONS.

The aim of the study was to compare Georgian PAH mutation spectrum to the most frequent European mutations. Population study publications were reviewed and 20 most frequent European PAH mutations were determined. Mutations were detected in 40 Georgian PKU patients using Sanger sequencing. PAH mutations were detected on all 80 alleles, clinical diagnose of PKU was confirmed in all 40 patients. Detected mutations in Georgian population was: P281L in 37.5%, IVS10-11G>A in 17.5%, R261X in 10%, L48S in 8.75%, E280K in 5%, R270K in 3.75%, E390G in 3.75% and mutations R252W, IVS12+1G>A, R243Q, R261Q, 1089delG, Y387H, EX5del, IVS7-5T>C, IVS12+1G>A, G171R, IVS2+5G>C each in 1.25%. Study revealed that the most common Georgian PAH mutations spectrum differs from the European one. 9 out of 18 detected mutations coincide with the European panel. At the same time more than half (55%) of the mutations found in Georgians were not identified as the most common mutations in Europe. These findings may indicate the necessity for the development of diagnostic panels specific to the Georgian population, including both 9 frequent European PAH mutations and 9 mutations more common for the Georgian population, which will significantly improve the quality of PKU diagnostics in Georgia. The results have been obtained are of an intermediate nature, which propose to continue and complete this research by studying the entire Georgian PKU population.