Rationale: Cystic fibrosis (CF; OMIM 219700) is a  common hereditary disease caused by mutations in the CFTR gene (OMIM 602421). The distribution and frequencies of the CFTR gene mutations vary considerably between countries and ethnic groups. By now about 11%  alleles of the CFTR gene remain unidentified after testing for frequent mutations in the Russian patients. A full determination of the mutation spectrum in the CFTR gene is necessary to optimize medical and genetic assistance to the population and to implement the achievements of targeted therapy in the treatment of CF patients.Materials and methods: The sample included 121 Russian CF patients, in whom testing for 34 routinely analyzed mutations did not identify one (n = 107) or both (n = 14) mutant alleles. Assessment of the coding sequence of the CFTR gene, including the regions of exon-intron junctions, 5’- and 3’-untranslated regions was performed by the Sanger sequencing method; in addition, the search for large rearrangements was conducted by the multiplex ligation-dependent probe amplification (MLPA) method.Results: In addition to the previously identified, 88  more variants were determined, including 28  missense mutations, 15  nonsense mutations, 18 frameshift mutations (14 deletions, 4  insertions), 14  splicing mutations, 1  in-frame insertion, 1  in-frame deletion, 1  in/del mutation, and 10  large rearrangements (7  deletions, 3  duplications). Twenty three (23) novel variants were sequenced. Four (4) complex mutant alleles were found. Sixty (60) variants are found once each. One hundred and thirty four (134) of 135 tested mutant alleles were identified.Conclusion: Consequent use of the sequencing and MLPA methods has allowed for identification of a high proportion of the tested mutant alleles in CF patients from Russia (134/135, > 99%), to detect a  significant diversity of the CFTR mutation spectrum (88  additional variants, 32  of them novel), a  number of repeated mutations (c.2353C>T, c.1240_1244delCAAAA, c.1766+1G>A and c.3929G>A) encountered in 5 or more unrelated patients, which could be included in the panel of routinely analyzed variants in the Russian CF patients; and a high proportion of large rearrangements of the CFTR gene.

AS-OCT and LSCM are both important diagnostic tools for corneal surface monitoring in patients with limbal stem cells deficiency.

Aim. The objective of the present study was to elucidate the specific features of the clinical picture of congenital aniridia in the children and adolescents and determine the frequency of complications of this pathology in the Russian Federation. Materials and methods. The study involved 37 children and adolescents at the age below 18 years (74 eyes) who were recruited from 37 unrelated families and diagnosed as having congenital aniridia at the Cheboksarsky branch of S.N. Fedorov Federal State Institute of Eye Microsurgery. All the children underwent the comprehensive ophthalmological examination based at this institution that included determination of the patients’ age and gender, diagnostics of keratopathy, cataract and glaucoma, measurements of foveal hypoplasia and hypoplasia of the optical nerve. In addition, visual acuity (VA) and the type of refraction were determined, gonioscopy and central keratopachymetry were performed on each patient. Results. The age of the patients varied from 2 months to 18 years (median: 3 years). The familial type of inheritance of congenital aniridia was documented in 16 patients whereas sporadic cases of this pathology were detected in 21 (56.7%) children. Microcornea and microphthalmus occurred in 4 and 2 eyes respectively. WAGR syndrome was diagnosed in 9.5% of the patients presenting with sporadic aniridia. Visual acuity was estimated at => 0.1 in 52% of the cases; it was => 0.3 in three patients. Abnormal refraction was documented in 88.3% of the children, marked hypermetropia was diagnosed in 15% of the examined eyes. The signs of aniridic keratopathy in the newborn infants and young children(aged below 3 years) were found in 64% of the cases. The youngest age at which the signs of aniridic keratopathy were apparent was 14 months. Cataract of different severity was documented in 77% of the eyes, glaucoma in 22.6%, foveal hypoplasia in 94%, and nystagmus in 86.5% of the eyes. The thickness of the central cornel region in the children at the age from 6 months to 2 years was 635+-47 microns compared with 606+-43 microns in the patients from 3 to 18 years of age. Conclusion. Congenital aniridia is a progressive panocular pathology affecting various structures of the eye and leading to the impairment of the visual function from the very early life.

Врожденная аниридия (OMIM#106210) (ВА) - наследственное аутосомно-доминантное заболевание, ассоциированное с внутригенными мутациями гена PAX6 или крупными хромосомными аберрациями с вовлечением региона 11p13 в гетерозиготном состоянии. Проведено изучение особенностей спектра мутаций гена PAX6 и региона 11p13 в когорте пациентов с ВА из России. Обследованы 184 пациента из 152 неродственных семей. У 17 пациентов из 12 неродственных семей в регионе 11p13 обнаружены сходные делеции дистантной 3'-цис-регуляторной области гена PAX6 размером 0,3-1,5 млн п.н. Частота 3'-цис делеций составила 8% (12/152) и превысила частоту обычной нонсенс мутации в гене PAX6 c.718C>T (9/152, 6%). Высокая частота делеций указывает на возможно общий механизм их образования в «горячем» локусе региона 11p13. Aniridia (OMIM 106210) is an autosomal dominant congenital disorder caused by heterozygous PAX6 intragenic mutations or chromosome 11p13 rearrangements. Molecular genetic study aimed to determine PAX6 damage spectrum peculiarities in Russian cohort. 152 unrelated families with congenital aniridia (184 patients) underwent ophthalmic examination and DNA testing. 17 patients from 12 unrelated families (4 familial and 8 sporadic probands) shared likely the same 11p13 0.3-1.5 Mb deletion affecting PAX6 downstream regulatory regions. The frequency of these deletions, 8% (12/152), was higher than PAX6 hotspot c.718C>T rate (8/152, 6%). A high rate of the deletions suggests a common underlying mechanism of its formation and points to 11p13 genomic region instability.