Epidemiology of Rare Hereditary Diseases in the European Part of Russia: Point and Cumulative Prevalence

Epidemiology of PAX6 Gene Pathogenic Variants and Expected Prevalence of PAX6-Associated Congenital Aniridia across the Russian Federation: A Nationwide Study

This study investigates the distribution of PAX6-associated congenital aniridia (AN) and WAGR syndrome across Russian Federation (RF) districts while characterizing PAX6 gene variants. We contribute novel PAX6 pathogenic variants and 11p13 chromosome region rearrangements to international databases based on a cohort of 379 AN patients (295 families, 295 probands) in Russia. We detail 100 newly characterized families (129 patients) recruited from clinical practice and specialized screening studies. Our methodology involves multiplex ligase-dependent probe amplification (MLPA) analysis of the 11p13 chromosome, PAX6 gene Sanger sequencing, and karyotype analysis. We report novel findings on PAX6 gene variations, including 67 intragenic PAX6 variants and 33 chromosome deletions in the 100 newly characterized families. Our expanded sample of 295 AN families with 379 patients reveals a consistent global PAX6 variant spectrum, including CNVs (copy number variants) of the 11p13 chromosome (31%), complex rearrangements (1.4%), nonsense (25%), frameshift (18%), and splicing variants (15%). No genetic cause of AN is defined in 10 patients. The distribution of patients across the Russian Federation varies, likely due to sample completeness. This study offers the first AN epidemiological data for the RF, providing a comprehensive PAX6 variants spectrum. Based on earlier assessment of AN prevalence in the RF (1:98,943) we have revealed unexamined patients ranging from 55% to 87%, that emphases the need for increased awareness and comprehensive diagnostics in AN patient care in Russia.

Step-by-Step Double-Trouble OBAIRH and DMD Diagnosis in a One-Year-Old Boy

We present a case of a combination of two rare hereditary disorders: obesity, adrenal insufficiency and red hair syndrome (OBAIRH) and Duchenne muscular dystrophy (DMD) in a boy. Both diseases were diagnosed during the first year of life. OBAIRH was suggested based on the ethnicity and family history of the patient, while DMD was based on an extreme increase in transaminase and CK (creatine kinase) levels during a biochemical analysis of his blood. The OBAIRH syndrome was caused by a pathogenic homozygous variant in the regulatory region of the POMC gene (NM_001035256.3): c.-71+1G>A, while DMD was caused by the de novo deletion of exons 38-45 of the DMD (NM_004006.3) gene (NC_000023.10:g.(?_32380941)(31950285_?)del).

The Presentation of Two Unrelated Clinical Cases from the Republic of North Ossetia-Alania with the Same Previously Undescribed Variant in the COL6A2 Gene

Here, we described three affected boys from two unrelated families of Ossetian-Digor origin from the Republic of North Ossetia-Alania who were admitted to the Research Centre for Medical Genetics with unspecified muscular dystrophy. High-throughput sequencing was performed and revealed two novel frameshift variants in the COL6A2 gene (NM_001849.3) in a heterozygous state each in both cases: c.508_535delinsCTGTGG and c.1659_1660del (case 1) and c.1689del and c.1659_1660del (case 2). In two cases, the same nucleotide variant in the COL6A2 gene (c.1659_1660del) was observed. We have suggested that the variant c.1659_1660del may be common in the Ossetian-Digor population because two analyzed families have the same ancestry from the same subethnic group of Ossetians). The screening for an asymptomatic carriage of the nucleotide variant c.1659_1660del in 54 healthy donors from Ossetian-Digor population revealed that the estimated carrier frequency is 0.0093 (CI: 0.0002–0.0505), which is high for healthy carriers of the pathogenic variant. Molecular genetic, anamnestic data and clinical examination results allowed us to diagnose Ullrich muscular dystrophy in those affected boys. Genetic heterogeneity and phenotypic diversity of muscular dystrophies complicate diagnosis. It is important to make a differential diagnosis of such conditions and use HTS methods to determine the most accurate diagnosis.

The Awareness of Rare Diseases Among Medical Students and Practicing Physicians in the Republic of Kazakhstan. An Exploratory Study

Although national plans or strategies for rare diseases (RDs) have been implemented in many jurisdictions research show that one of the main barriers RD patients face during medical encounter is medical professionals' low level of knowledge and experience on the diagnosis, treatment and rehabilitation of RD patients. Consequently, there is a need to increase the standards of medical education in the field of RDs and to revise the undergraduate and postgraduate training programs. However, while studies on medical education in the field of RDs has been conducted in various countries across the both Americas, Asia or the European Union, still little is known about the awareness of RDs among healthcare professionals in the Republic of Kazakhstan. Thus, we conducted a survey among 207 medical students and 101 medical doctors from the West Kazakhstan Marat Ospanov Medical University, Aktobe, Kazakhstan. The study was conducted between March and May 2021. The questionnaire assessed their knowledge about the number, examples, etiology and estimated frequency of RDs. It also evaluated respondents self-assessment of competence in RDs. Although the majority of respondents agreed that RDs constitute a serious public health issue both medical students and medical doctors showed insufficient knowledge on the etiology, epidemiology and prevalence of RDs, and many had problems with separating RDs from more common disorders. Moreover, they also lacked knowledge about and the central register of RD patients and reimbursement of orphan drugs in Kazakhstan. Finally, while almost half respondents declared having had classes about RDs during their studies most perceived their knowledge about RDs as insufficient or poor and felt unprepared for caring for RD patients. Additionally, although majority of respondents in both groups believed that all physicians, regardless of their specialization, should possess knowledge on RDs many respondents did not look for such information at all.

The Awareness of Rare Diseases Among Medical Students and Practicing Physicians in the Republic of Kazakhstan. An Exploratory Study

Although national plans or strategies for rare diseases (RDs) have been implemented in many jurisdictions research show that one of the main barriers RD patients face during medical encounter is medical professionals' low level of knowledge and experience on the diagnosis, treatment and rehabilitation of RD patients. Consequently, there is a need to increase the standards of medical education in the field of RDs and to revise the undergraduate and postgraduate training programs. However, while studies on medical education in the field of RDs has been conducted in various countries across the both Americas, Asia or the European Union, still little is known about the awareness of RDs among healthcare professionals in the Republic of Kazakhstan. Thus, we conducted a survey among 207 medical students and 101 medical doctors from the West Kazakhstan Marat Ospanov Medical University, Aktobe, Kazakhstan. The study was conducted between March and May 2021. The questionnaire assessed their knowledge about the number, examples, etiology and estimated frequency of RDs. It also evaluated respondents self-assessment of competence in RDs. Although the majority of respondents agreed that RDs constitute a serious public health issue both medical students and medical doctors showed insufficient knowledge on the etiology, epidemiology and prevalence of RDs, and many had problems with separating RDs from more common disorders. Moreover, they also lacked knowledge about and the central register of RD patients and reimbursement of orphan drugs in Kazakhstan. Finally, while almost half respondents declared having had classes about RDs during their studies most perceived their knowledge about RDs as insufficient or poor and felt unprepared for caring for RD patients. Additionally, although majority of respondents in both groups believed that all physicians, regardless of their specialization, should possess knowledge on RDs many respondents did not look for such information at all.