DMD/BMD Hastalarında Genetik Spektrum: Tek Merkezden MLPA ve Sanger Sonuçları

Yıl 2025, Cilt: 22 Sayı: 4

Zehra Manav Yiğit , Büşra Sapmaz , Müge Ayanoğlu

Öz

Amaç: Duchenne ve Becker Musküler Distrofi (DMD/BMD), distrofin proteinini kodlayan DMD genindeki değişimlere bağlı olarak gelişen, ilerleyici kas güçsüzlüğü ve kaybı ile seyreden X’e bağlı resesif kalıtılan bir nöromüsküler hastalıktır. Bu çalışmanın amacı, genetik analiz ile DMD geninde varyant saptanmış ve DMD/BMD tanısı almış olguların genetik ve klinik özelliklerini değerlendirmektir.
Materyal ve metot: Bu retrospektif çalışmada, DMD geni analizi ile moleküler tanısı doğrulanmış 32 aileden 34 erkek DMD/BMD olgusu (DMD tanısı alan 24 olgu (%70,6) ve BMD tanısı alan 10 (%29,4) olgu) değerlendirildi. Klinik, biyokimyasal ve aile öyküsü verileri hasta dosyalarından elde edildi. Hastaların genetik analizleri çoklu ligasyon bağımlı prob amplifikasyonu (MLPA) ve Sanger dizileme yöntemleriyle gerçekleştirilmişti. 15 anneden taşıyıcılığa yönelik segregasyon analizi yapılmıştı.
Bulgular: Olguların %79,4’ünde ekzon delesyonu, %20,6’sında küçük varyant tespit edildi. En sık delesyon bölgeleri 45-52. ekzonlar arasındaydı. CK düzeyleri tüm hastalarda yüksek saptanmıştı. Ortalama tanı yaşı 5’ti. Segregasyon analizi yapılan annelerden 12 tanesinin çocuğunda saptanan varyantı taşıdığı gösterilmişti. Kohortumuzda daha önce literatürde bildirilmemiş 3 yeni varyant saptanmıştır.
Sonuç: DMD/BMD olgularında genetik analizler tanı koymada, fenotipik öngörüde bulunmada ve aile taramasında oldukça değerlidir. Bu çalışmada, Türkiye’den bildirilen olgulara katkı sağlayacak şekilde, DMD/BMD’ye neden olan varyant tipleri ve klinik özellikler ortaya konmuştur. Moleküler tanının etkin kullanımı, erken tanı ve yönetim için önem taşımaktadır.

Anahtar Kelimeler

DMD , BMD , MLPA , Sanger dizileme , Novel varyant

Genetic Profile of DMD/BMD: MLPA and Sanger Sequencing Results from a Single Center

Öz

Background: Duchenne and Becker Muscular Dystrophy (DMD/BMD) is an X-linked recessive inherited neuromuscular disease characterised by progressive muscle weakness and wasting due to variants in the DMD gene encoding dystrophin protein. This study aimed to evaluate the genetic and clinical characteristics of patients diagnosed with DMD/BMD who were found to have variants in the DMD gene by genetic analysis.
Material and Methods: In this retrospective study, we evaluated 34 patients from 32 families diagnosed with dystrophinopathies, including 24 individuals (70.6%) with DMD and 10 individuals (29.4%) with BMD. Clinical, biochemical, and family history data were obtained from patient files. Genetic analyses were performed by multiple ligation-dependent probe amplification (MLPA) and Sanger sequencing. 15 mothers were segregated for carriage.
Results: Exon deletion was detected in 79.4% of cases, and a small variant in 20.6%. The most common deletion sites were between exons 45-52. CK levels were found to be high in all patients. The mean age at diagnosis was 5 years. Segregation analysis showed that 12 of the mothers carried the variant detected in their children. Three new variants that had not been reported in the literature before were found in our cohort.
Conclusions: Genetic analyses are valuable in diagnosis, phenotypic prediction, and family screening in DMD/BMD cases. In this study, the variant types and clinical features of DMD/BMD were analysed to contribute to the reported cases from Türkiye. Effective use of molecular diagnosis is important for early diagnosis and management.

Anahtar Kelimeler

DMD , BMD , MLPA , Sanger sequencing , Novel variants

Etik Beyan

This study was approved by the Non-Interventional Clinical Research Ethics Committee of Aydın Adnan Menderes University Faculty of Medicine (Approval No: 19, Date: January 26, 2025).

Kaynakça

• 1. Mohammed F, Bastaki M, Al-Hashel M, Al-Kandari A, Al-Awadhi N, Elshafey AA, et al. Mutation spectrum analysis of Duchenne/Becker muscular dystrophy in 68 families in Kuwait: the era of personalized medicine. PLoS One. 2018;13(5):e0197205.
• 2. Ramirez MP, Nguyen JK, Patel SH, Lee C, Mooney DJ, Spurlin KL, et al. Dystrophin missense mutations alter focal adhesion tension and mechanotransduction. Proc Natl Acad Sci USA. 2022;119(25):e2205536119. 3. Duan D, Goemans N, Takeda S, Mercuri E, Aartsma-Rus A. Duchenne muscular dystrophy. Nat Rev Dis Primers. 2021;7(1):13.
• 4. Mathur P, Kaur A, Agarwal KK, Agarwal LK, Mathur A, Choudhary D. Unlocking the genetic blueprint of Duchenne muscular dystrophy: a personalized approach with MLPA and WES. Glob Med Genet. 2025;12(2):100038.
• 5. Salari N, Kazeminia M, Valipour F, Shohaimi S, Jalali A, Mohammadi M, et al. Global prevalence of Duchenne and Becker muscular dystrophy: a systematic review and meta-analysis. J Orthop Surg Res. 2022;17(1):96.
• 6. Nicolardi V, Dell’Abate CFI, Reni G, Sicca F, Della Monica MT, Santorelli FM, et al. Social cognition in two brothers with Becker muscular dystrophy: an exploratory study revealing divergent behavioral phenotypes. Neurol Sci. 2024;45(7):3471-3479.
• 7. Davies KE, Vogt J. Long-term clinical follow-up of a family with Becker muscular dystrophy associated with a large deletion in the DMD gene. Neuromuscul Disord. 2024;39:5-9.
• 8. Fechner A, Willenberg A, Ziegelasch N, Merkenschlager A, Kiess W, Vogel M. Creatine kinase serum levels in children revisited: New reference intervals from a large cohort of healthy children and adolescents. Clin Chim Acta. 2024;560:119726.
• 9. Richards S, Aziz V, Bale S, Bick D, Das S, Gastier-Foster D, et al. Standards and guidelines for the interpretation of sequence variants: a joint consensus recommendation of the American College of Medical Genetics and Genomics and the Association for Molecular Pathology. Genet Med. 2015;17(5):405-424.
• 10. Leiden Open Variation Database [Gene variant database].
• 11. Universal Mutation Database (UMD)-DMD Database [Gene variant database].
• 12. National Center for Biotechnology Information ClinVar. [Online database].
• 13. Ozkalayci H, Kaya IC, Aydin AA, Tasci GT, Erdem-Ozdamar ES, Gunel-Ozcan B, et al. Investigation of genotype-phenotype and familial features of Turkish dystrophinopathy patients. Neurogenetics. 2024;25(3):201-213.
• 14. Öztürk FN, Özyavuz Çubuk P, Akın Duman T. The spectrum of dystrophin gene deletions and duplications in a cohort of patients with Duchenne/Becker muscular dystrophy in Türkiye. Osmangazi J Med. 2024;46(1):9-16.
• 15. Çavdarlı B, Köken Ö, Ceylan AC, Semerci CN, Topaloğlu H. Genetic landscape of dystrophin gene deletions and duplications from Turkey: a single center experience. Turk J Pediatr Dis. 2021;15(4):1-6.
• 16. Guo R, Zhou H, Gu X, Wang J, Zhang M, Lin X, et al. DMD mutation spectrum analysis in 613 Chinese patients with dystrophinopathy. J Hum Genet. 2015;60(8):435-442.
• 17. Viggiano E, Picillo A, Politano R, Savarese M, Nigro M, Piluso V, et al. Spectrum of genetic variants in the dystrophin gene: a single centre retrospective analysis of 750 Duchenne and Becker patients from Southern Italy. Genes (Basel). 2023;14(1):214.
• 18. Vieitez I, González-Mera S, González-Quereda A, Fernández-Torrón M, Gallardo B, Baiget E, et al. Mutational spectrum of Duchenne muscular dystrophy in Spain: study of 284 cases. Neurología. 2017;32(6):377-385.
• 19. Zamani G, Moghadam MM, Fard FK, Mokhtari HM, Bahar MB, Dastgheib MR, et al. The first comprehensive cohort of the Duchenne muscular dystrophy in Iranian population: Mutation spectrum of 314 patients and identifying two novel nonsense mutations. J Mol Neurosci. 2020;70(10):1565-1573.
• 20. Amr K, Fahmy N, El-Kamah G. Genomic insights into Duchene muscular dystrophy: Analysis of 1250 patients reveals 30% novel genetic patterns and 6 novel variants. J Genet Eng Biotechnol. 2024;22(4):100436.
• 21. Ioannidis NM, Rothstein JA, Pejaver EA, Middha DY, McDonnell KD, Shendure AM, et al. REVEL: An ensemble method for predicting the pathogenicity of rare missense variants. Am J Hum Genet. 2016;99(4):877-885.
• 22. Desmet FO, Hamroun D, Lalande M, Collod-Béroud G, Claustres M, Béroud C. Human Splicing Finder: an online bioinformatics tool to predict splicing signals. Nucleic Acids Res. 2009;37(9):e67.
• 23. Verebi C, Gravrand V, Bienvenu T, Leturcq F, Nectoux J. A retrospective cohort study and review of the literature about germline mosaicism in Duchenne/Becker muscular dystrophy prenatal counseling: How to estimate the recurrence risk in clinical settings? J Genet Couns. 2025;34(1):e1932.
• 24. Pickart AM, Conlin MM, Moore LM, Heiman-Patterson RA, Smith EL, Sullivan KA, et al. Genetic counseling for the dystrophinopathies—Practice resource of the National Society of Genetic Counselors. J Genet Couns. 2025;34(1):e1892.
• 25. Hoefel AML, Weschenfelder CA, Rosa BF, Donis KC, Saute JAM. Empowerment of genetic information by women at-risk of being carriers of Duchenne and Becker muscular dystrophies. J Community Genet. 2024;15(2):163-175.
• 26. Singer A, Aartsma-Rus A, Grinshpun-Cohen J, Sagi-Dain L. Lessons learned from the first national population-based genetic carrier-screening program for Duchenne muscular dystrophy. Genet Med. 2023;25(12):100981.