Genotype-phenotype correlation in siblings with cystic fibrosis

Introduction. Despite the genetic counseling, families with cystic fibrosis (CF) patients and modern possibilities of prenatal molecular screening, occurrence CF in more than one child a family is not rare. The same genotype expected to determine specific phenotype patients, especially siblings. However, broad clinical heterogeneity could indicate influence secondary factors on course disease.
 aim study examine genotype-phenotype correlation disease features siblings, including twins.
 Materials methods. A retrospective cohort observational included fifty three sibs (23 boys, 30 girls) aged from 6 months 17 years 9 (median age 8.3 (4.8–12.9) years, difference 5 ± 2 years) diagnosis confirmed by Group 1 consisted twin pairs (3 — monozygotic, dizygotic), group 35 complete sibs.
 Results. mean for older 2.5 (8 9,8 years; min months, max younger 8.5 (1.3 months–3 years). Chronologically, onset was registered earlier 3 (16.7%). In (22.2%) families, pancreatic status varied normal function severe insufficiency, pancreatitis observed only 4 (7.6%) patients. 21 (77.8%) infected P.aeruginosa, (23.8%) had simultaneous primary culture pathogen, 8 (38,1%) both children but an interval month 9.5 (Ме: 3.2 (5 months–4.9 years), (38.1%) sibling. All contamination at 5.3 year (2–6.6 years;) difference. 10 (37.0%) pulmonary variable. number bronchopulmonary exacerbations per ranged (29.6%) sib averaged 1.3 0.5 sibs, 1.1 0.3 1.7 twins. severity hepatic involvement (33.3%) pairs: no morbidity (33.3%), fibrosis-associated 7 (38.9%), cirrhosis portal hypertension (27.8%).
 Conclusion. despite genotype, similar environmental conditions, high risk cross-infection, are characterized wide phenotypic heterogeneity. Aside pathogenic CFTR variants, there other (modifier genes) epigenetic (microRNA, DNA methylation) that contribute fibrosis.