Effect of genotype on selected clinical features of Polish cystic fibrosis adults.

UNLABELLED: Cystic fibrosis (CF), the most common autosomal recessive disorder of Caucasians, is caused by the mutations in the gene encoding CFTR (Cystic Fibrosis Transmembrane Conductance Regulator) protein. Until now, approximately 1000 mutations of the CFTR gene have been described. The genotype-phenotype relationships in CF are still not completely understood. This study was undertaken in an attempt to characterise the distribution of CFTR mutations and their effect on selected clinical parameters in a group of Polish CF adults. A total number of 38 adult CF patients (mean age 21.6 +/- 6.8); 18 females & 20 males were enrolled in the study. The CFTR gene identification was conducted with the use of PCR & InnoLipa-CF set. The assessed clinical parameters included: age at diagnosis, age, lung function test, X-ray scored in Brasfield score, weight & height. We found that: (1) the genotypes of the studied population were unevenly distributed (65.8%- genotype deltaF508/M), (2) a high percentage of 3849+10kbC-->T was noted, (3) patients homozygous for the deltaF508 mutation were diagnosed significantly earlier and had a lower body mass index, (4) no differences were observed in the patients' length of life or the progression of lung disease. CONCLUSIONS: 1. In comparison to other populations, Polish adult CF patients display a relatively higher frequency of mild mutations. 2. Late diagnosis of CF in the studied group may be partially caused by a high percentage of CFTR mutations connected with the mild course of the disease that are difficult to identify. 3. Cystic fibrosis should be more commonly taken into consideration in the differential diagnosis in adult patients with milder symptoms.

[Frequency of mutations and genotypes of the CFTR gene in cystic fibrosis adults in Poland]. / Czestosc wystepowania mutacji oraz genotypów genu CFTR u doroslych chorych na mukowiscydoze w Polsce.

Based on the Polish Registry of Cystic Fibrosis the analysis of alive CF adults (18 y.a. and more) was performed. Out of 156 Polish CF adults, in 106 (68.0%) identification of the CFTR gene mutations was performed. Relative frequencies of 24 mutations of CFTR gene mutations is 72.2%. Frequencies of the most common mutations are: delta F508 49.06%, 3849 + 10kbCT 8.96%, G542X 1.89%; in Polish CF adults mutations other than delta F508 comprise 23.13% of CF alleles. The most common genotype delta F508/delta F508 occurs with the frequency 22.6%, significantly lower than in CF children; genotype delta F508/3849 + 10kbCT occurs with the frequency 11.3%, and this value is significantly higher than in other age groups.