First IKBKG gene mutation study in Serbian incontinentia pigmenti patients

SUMMARY Introduction Incontinentia pigmenti (IP) is a rare X-linked dominant genodermatosis. Mutations of the IKBKG gene are the only known cause of IP. The presence of other than skin changes is important in the diagnosis of atypical IP cases when skin changes are discrete. Objective The study was designed to analyze clinical manifestation, family histories and the frequency of IKBKG gene mutation in IP patients in Serbia for the first time and to compare them with other reported findings. Methods Two Serbian unrelated families with eight female subjects were investigated. Blood samples were used for IKBKG exon 4-10 deletion testing using modified PCR protocol. For probands pathohisto- logical and ultrastructural analyses of skin biopsies were done. Results Positive clinical diagnosis according to IP criteria was present in seven cases. In six of them, including probands, positive molecular gene testing for IKBKG exon 4-10 deletion was present. Conclusion This is the first report of genetically confirmed IP in two Serbian families. The IP patients presented a common IKBKG exon 4-10 deletion. The frequency and type of IKBKG mutation found in investigated IP patients in Serbia were similar to results of other studies. Various clinical features of investigated patients have allowed us to demonstrate that molecular genetic testing which specifically detects the common IKBKG mutations, the only known cause of IP, is useful in diagnosing IP especially in mild or atypical cases. The molecular genetic testing of the IKBKG mutations may be helpful for rapid confirmation of IP diagnosis, prenatal diagnosis and carrier detection. Keywords: Incontinentia pigmenti; IKBKG gene; IKBKG exon 4-10 deletion; X-chromosome; X-chromo- some inactivation; phenotype