Profile of Inherited Neuromuscular and Movement Disorders Among Filipinos: A Referral Single-Center Retrospective Study

Abstract

Background: Neuromuscular and movement disorders comprise a heterogeneous group of acquired and inherited conditions affecting the motor unit and central movement pathways. Genetic data from underserved populations, including Filipinos, remain limited, highlighting the need for population-specific characterization.

Objective: To characterize inherited neuromuscular and movement disorders among Filipinos and determine the diagnostic yield and genetic spectrum using next-generation sequencing (NGS).

Methods: This referral single-center retrospective study reviewed Filipino patients who underwent genetic testing for suspected inherited neuromuscular and movement disorders. Variants were classified according to the American College of Medical Genetics and Genomics (ACMG) criteria.

Results: Among 85 patients, 24 (28.2%) had pathogenic/likely pathogenic variants, 33 (38.8%) had variants of uncertain significance (VUS) and 28 (32.9%) were negative. Confirmed diagnoses included pediatric cases of limb-girdle muscular dystrophy, Duchenne muscular dystrophy, spinal muscular atrophy and GNE-related myopathy, and adult cases with myofibrillar myopathy, spinocerebellar ataxia and amyotrophic lateral sclerosis. Pathogenic variants involved 26 genes, most commonly SMN1.

Conclusion: This NGS-based characterization of inherited neuromuscular and movement disorders in Filipinos showed 28% diagnostic yield and a spectrum comparable to other Asian cohorts. The high rate of VUS underscores the need for family segregation studies and careful genotype–phenotype correlation. This study highlights the critical role of genetic testing in accurate diagnosis and targeted management to improve outcomes for patients with these rare disorders.

  1. Lace B, Micule I, Kenina V, Setlere S, Strautmanis J, Kazaine I, et al. Overview of neuromuscular disorder molecular diagnostic experience for the population of Latvia. Neurol Genet [Internet]. 2022;8(3):e685. Available from: http://dx.doi.org/10.1212/NXG.0000000000000685 
  2. Deenen JCW, Horlings CGC, Verschuuren JJGM, Verbeek ALM, van Engelen BGM. The epidemiology of neuromuscular disorders: A comprehensive overview of the literature. J Neuromuscul Dis [Internet]. 2015;2(1):73–85. Available from: http://dx.doi.org/10.3233/jnd-140045. PMID: 28198707. 
  3. Woodcock IR, Fraser L, Norman P, Pysden K, Manning S, Childs A-M. The prevalence of neuromuscular disease in the paediatric population in Yorkshire, UK; variation by ethnicity and deprivation status. Dev Med Child Neurol [Internet]. 2016;58(8):877–83. Available from: http://dx.doi.org/10.1111/dmcn.13096 
  4. Chung B, Wong V, Ip P. Prevalence of neuromuscular diseases in Chinese children: a study in southern China. J Child Neurol [Internet]. 2003;18(3):217–9. Available from: http://dx.doi.org/10.1177/08830738030180030201. PMID: 12731646.
  5. Pajo AT, Espiritu AI, Jamora RDG. Scientific impact of movement disorders research from Southeast Asia: A bibliometric analysis. Parkinsonism Relat Disord [Internet]. 2020;81:205–12. Available from: http://dx.doi.org/10.1016/j.parkreldis.2020.10.043 
  6. Wilson LA, Macken WL, Perry LD, Record CJ, Schon KR, Frezatti RSS, et al. Neuromuscular disease genetics in under-represented populations: increasing data diversity. Brain [Internet]. 2023;146(12):5098–109. Available from: http://dx.doi.org/10.1093/brain/awad254 
  7. Jagota P, Lim S-Y, Pal PK, Lee J-Y, Kukkle PL, Fujioka S, et al. Genetic movement disorders commonly seen in Asians. Mov Disord Clin Pract [Internet]. 2023;10(6):878–95. Available from: http://dx.doi.org/10.1002/mdc3.13737. PMID: 37332644; PMCID: PMC10272919.
  8. Chakravorty S, Nallamilli BRR, Khadilkar SV, Singla MB, Bhutada A, Dastur R, et al. Clinical and genomic evaluation of 207 genetic myopathies in the Indian subcontinent. Front Neurol [Internet]. 2020;11(559327):559327. Available from: http://dx.doi.org/10.3389/fneur.2020.559327 
  9. Sharma S, Govindaraj P, Chickabasaviah YT, Siram R, Shroti A, Seshagiri DV, et al. Genetic spectrum of inherited neuropathies in India. Ann Indian Acad Neurol [Internet]. 2022;25(3):407–16. Available from: http://dx.doi.org/10.4103/aian.aian_269_22 
  10. Dai Y, Wei X, Zhao Y, Ren H, Lan Z, Yang Y, et al. A comprehensive genetic diagnosis of Chinese muscular dystrophy and congenital myopathy patients by targeted next-generation sequencing. Neuromuscul Disord [Internet]. 2015;25(8):617–24. Available from: http://dx.doi.org/10.1016/j.nmd.2015.03.002 
  11. Seong M-W, Cho A, Park HW, Seo SH, Lim BC, Seol D, et al. Clinical applications of next-generation sequencing-based gene panel in patients with muscular dystrophy: Korean experience: Clinical applications of NGS in muscular dystrophy. Clin Genet [Internet]. 2015;89(4):484–8. Available from: http://dx.doi.org/10.1111/cge.12621 

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