GENETIC AND EPIDEMIOLOGICAL ASPECTS OF LOUIS-BAR SYNDROME TRANSMISSION - THE IMPACT OF CONSANGUINEOUS MARRIAGES ON THE INCIDENCE OF HEREDITARY DISORDERS

Sep 29, 2026

Genetic and epidemiological determinants of Louis-Bar syndrome transmission were investigated in Kyrgyzstan with emphasis on consanguineous marriages. The study reports a clinical case of a family with three affected children showing progressive cerebellar ataxia, conjunctival and cutaneous telangiectasias, recurrent infections, and delayed psychomotor development. Brain MRI demonstrated cerebellar atrophy in the oldest child and cerebellar subatrophy in the others. Pedigree analysis identified consanguinity in the third generation, and molecular testing detected a homozygous ATM c.5932G > A mutation.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages17

Reading Time43 min

AccessFree to download

Abstract

Background

Methods

Results

Conclusion

Introduction

Clinical features of Louis-Bar syndrome

Molecular basis and inheritance

Case description and evidence

MRI findings

Pedigree and consanguinity

Genetic testing

Case study • DOI: 10.34763/jmotherandchild.20252901.d-25-00038 • JMC 2025;29(1):234-250 Journal of Mother and Child GENETIC AND EPIDEMIOLOGICAL ASPECTS OF LOUIS-BAR SYNDROME TRANSMISSION: THE IMPACT OF CONSANGUINEOUS MARRIAGES ON THE INCIDENCE OF HEREDITARY DISORDERS Zhanyl Baitokova1,* , Nursultan Erkinbek uulu2,3 , Ajgul Matkeeva2,4 , Maral Turdumatova1,5 , Askarbekova Zhyldyz2 1Department of Public Health International Higher School of Medicine (IHSM) 720054, 1 F Intergelpo Str., Bishkek, Kyrgyz Republic 2National Center of Maternity and Childhood Care 720038, 190 Akhunbaev Str., Bishkek, Kyrgyz Republic 3Department of Neurology and Clinical Genetics named after A.M. Murzaliev I.K. Akhunbaev Kyrgyz State Medical Academy 720020, 92 Akhunbaev Str., Bishkek, Kyrgyz Republic 4Department of Faculty Pediatrics I.K. Akhunbaev Kyrgyz State Medical Academy 720020, 92 Akhunbaev Str., Bishkek, Kyrgyz Republic 5First Children’s Hospice 720016, 299/5 Chingiz AitmatovAve., Bishkek, Kyrgyz Republic Abstract ~~ ~~ Background: The aim of this study was to investigate the genetic and epidemiological aspects of Louis-Bar syndrome transmission in the population of Kyrgyzstan, with a particular focus on the impact of consanguineous marriages. Methods: The study presents a clinical case of a family with three children affected by this disorder. All children exhibited characteristic manifestations, including progressive cerebellar ataxia of varying severity; conjunctival and cutaneous telangiectasias; recurrent infections; and delayed psychomotor development. In the eldest child, the clinical presentation resembled the ataxic form of cerebral palsy. Standardised scales assessing motor, manual, and communicative functions were used to evaluate the severity of ataxia. Results: Brain magnetic resonance imaging confirmed cerebellaratrophy in the eldest child and cerebellar subatrophyin the middle and youngest children. All children demonstrated telangiectasias on the mucous membranes of the eyes and skin, as well as signs of immunodeficiency manifesting as frequent infections. Family pedigree analysis revealed consanguinity in the third generation (the maternal grandmother and paternal grandfather were biological siblings). Molecular genetic testing identified a homozygous c.5932G > A mutation in the ATM gene encoding a protein involved in DNA repair. Conclusion: The findings confirm that consanguineous unions increase the risk of developing Louis-Bar syndrome, as they elevate the likelihood of inheriting identical mutant alleles. This study highlights the importance of medical-genetic counselling and prenatal diagnostics in families at high risk of hereditary diseases, particularly in regions with a high prevalence of consanguineous marriages. Keywords ~~ ~~ Mutations, Autosomal Recessive Inheritance, Immunodeficiency, CerebellarAtrophy, Family Genetic Counselling, Telangiectasia, Paediatrics, Paediatric Neurology, MRI Diagnostics, Differential Diagnostics, Ataxic Form of Cerebral Palsy, Palliative Care Received: 2025 September 23 Accepted: 2025 November 3 Introduction Louis-Bar syndrome (LBS), also known as ataxiatelangiectasia (A-T), is a rare inherited disorder that leads to severe neurological impairment, immunodeficiency, and a substantial decline in patients’ quality of life. Its diagnosis presents a significant challenge due to the heterogeneity of its clinical manifestations, and the risk of *Corresponding author: Zhanyl Baitokova [e-mail: zhanylbaitokova@gmail.com](e-mail: zhanylbaitokova@gmail.com)[ ](e-mail: zhanylbaitokova@gmail.com)[Copyright](Copyright) © [2025](2025) Baitokova et al. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 Public License (CC BY) ([https://creativecommons.org/licenses/by/4.0/](https://creativecommons.org/licenses/by/4.0/)). The use, distribution or reproduction in other forums is permitted, provided the original author(s)

FAQs

What was the primary goal of the study?

To examine the genetic and epidemiological aspects of Louis-Bar syndrome transmission in Kyrgyzstan, focusing on how consanguineous marriages influence the risk of hereditary disorders.

How were the affected children clinically evaluated?

The children were assessed for progressive cerebellar ataxia severity using standardised scales, and for characteristic findings such as telangiectasias, recurrent infections, and delayed psychomotor development.

What evidence linked the case to Louis-Bar syndrome and ATM mutations?

Brain MRI supported cerebellar atrophy/subatrophy, and molecular genetic testing identified a homozygous c.5932G > A mutation in the ATM gene.

Sep 29, 2026

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