Discovery of a novel homozygous <i>SOD1</i> truncating variant bolsters infantile SOD1 deficiency syndrome


Dogan M., Terali K., ERÖZ R., Kilic H., Gezdirici A., Gonullu B.

MOLECULAR BIOLOGY REPORTS, cilt.51, sa.1, 2024 (SCI-Expanded, Scopus) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 51 Sayı: 1
  • Basım Tarihi: 2024
  • Doi Numarası: 10.1007/s11033-024-09513-6
  • Dergi Adı: MOLECULAR BIOLOGY REPORTS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Aquatic Science & Fisheries Abstracts (ASFA), BIOSIS, CAB Abstracts, Chemical Abstracts Core, Veterinary Science Database
  • İstanbul Üniversitesi-Cerrahpaşa Adresli: Evet

Özet

ObjectiveSuperoxide dismutase 1 (SOD1) is an important antioxidant enzyme whose main function is to neutralise superoxide free radicals in the cytoplasm. Heterozygous variants in SOD1 are responsible for a substantial percentage of familial amyotrophic lateral sclerosis (ALS) cases. Recently, several reports have shown that biallelic loss of SOD1 function results in a novel phenotype called infantile SOD1 deficiency syndrome, which is consistent with a recessive pattern of inheritance and can be distinguished from typical (adult-onset) ALS. Methods We documented detailed family histories and clinical data, followed by whole-exome sequencing and family co-segregation analysis through Sanger sequencing. To facilitate comparisons, relevant data from fifteen previously reported patients with SOD1-related neurodevelopmental disorders were included. Results This study presents a new Turkish family with two affected children exhibiting severe delayed motor development, infancy-onset loss of motor skills, axial hypotonia, tetraspasticity, and impaired cognitive functions. Genetic analysis revealed a novel homozygous frameshift variant in SOD1 (c.248dupG [p.Asp84Argfs*8]), with computational biochemical studies shedding light on the mechanistic aspects of SOD1 dysfunction. ConclusionsOur findings contribute an affirmative report of a fourth biallelic variant resulting in a severe clinical phenotype, reminiscent of those induced by previously identified homozygous loss-of-function SOD1 variants. This research not only advances our understanding of the pathogenesis of this debilitating neurological syndrome but also aligns with ongoing intensive efforts to comprehend and address SOD1-linked ALS.