Analysis of Two Polymorphic Repeats IVS3 Poly A and IVS10 CA in Tunisian Cystic Fibrosis Patients: Case–Control Study

The aim of this study was to determine a possible association of IVS3 poly A and IVS10 CA microsatellites with CF in case–control Tunisian groups and to compare the results with the findings in Italian population. Both microsatellites were analyzed by capillary electrophoresis in 70 normal subjects and 60 Tunisian CF patients. The statistical distribution of IVS3 poly A and IVS10 CA polymorphism shows a significant difference between CF patients and controls group. 12 different alleles were found for IVS3 poly A which only five were identified in CF patients. IVS3 poly (A)19 was the most prevalent allele in CF patients with 75%. Nevertheless, IVS3 poly (A)18 was more common in normal individuals (27.14%). Seven different alleles were found for IVS10 CA. The IVS10 (CA)16 was the most prevalent allele both in normal individuals and CF patients with 30.71 and 52.5% frequencies respectively. Concerning the association of these two markers with F508del mutation, we noted that IVS3 poly (A)19 is the most common in our CF patients but IVS3 poly (A)18 is specific to the CF Italian patients. Furthermore, IVS10 (CA)16 and IVS10 (CA)19 are the most dominant (29.16%) in our samples and IVS10 (CA)23 is specific to the CF Italian subjects (94.4%). Our study allowed us to identify the haplotype distribution of both markers IVS3 poly A and IVS10 CA in CF and control subjects. The results obtained show a strong association between the most frequent F508del mutation and IVS3 poly (A)19, IVS10 (CA)16 and IVS10 (CA)19.