Estimation of the cystic fibrosis mutation dF508 frequency in Latvia
Previous investigation of the mutation frequency in Latvia, were examined in pure latvian individuals (Krumina et al., 1996), revealing that the dF508 mutation frequency is 1:42. The estimation of the expected CF incidence in the Latvian population showed that the frequency of non-mild CF cases in newborns should be 1:3,300. An average yearly newborn in period 2000 to 2004 was 20,260 So, the expected estimated CF patient number should be 6 per year. However in this period only 5 new CF patients were registered. This mismatch we wanted to explain due to ethnic heterogeneity of Latvian inhabitants (Russians-28.6%, Belorussians-3.82%, Ukranians-2.55%, Lithuanians-1.37%). In these populations frequency of dF508 mutation is less common.
Aim of the study was to detect the frequency for dF508 mutation in the population of Latvia. 124 individuals were investigated (Latvians-59.67%, Russians-30.64%, Belorussians-3.22%, Ukranians-3.22%, Poles-3.22%). DNA diagnosis was performed using phenol-ethanol DNA extraction method and PCR technique. Four individuals were found to be carriers of dF508 mutation. Consequently, heterozygote frequency for the population of Latvia for CF dF508 mutation is 1:31.
On the beginning of the study it was expected that dF508 mutation frequency in the population of Latvia is less than previously reported. The mutation is found in increased rate than it was expected. Regarding to the results an expected number of CF patients in Latvia is much greater that we have at the present, meaning that CF in Latvia is misdiagnosed.