SLC7A6OS Founder Mutation: A Rare Cause of Progressive Myoclonus Epilepsy Dated to 1100 Years Ago
Movement Disorders, 2026 (SCI-Expanded, Scopus)
- Publication Type: Article / Article
- Publication Date: 2026
- Doi Number: 10.1002/mds.70516
- Journal Name: Movement Disorders
- Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, CINAHL, EMBASE, MEDLINE, Academic Search Ultimate (EBSCO), Biomedical Reference Collection: Corporate Edition (EBSCO), Health Research Premium Collection (ProQuest)
- Istanbul University Affiliated: Yes
Abstract
Background: SLC7A6OS c.191A>G is a rare, autosomal recessive cause of progressive myoclonus epilepsy (PME). The c.191A>G variant, first discovered in two families from Türkiye and Portugal, was recently identified in three additional probands from the USA, all of Puerto Rican ancestry. Objectives: We sought to refine the SLC7A6OS-PME phenotype and determine whether all families inherited the variant from the same common ancestor. Methods: Clinical and genotyping data were obtained from all five families. Haplotype analysis using single nucleotide polymorphism arrays to investigate a possible common ancestor was performed. Results: Shared haplotypes suggest all five families inherited the SLC7A6OS variant from a common ancestor approximately 1100 years ago. Subsequent dating estimates were consistent with migration patterns between the eastern Mediterranean, Iberia, and Puerto Rico. Conclusions: Our findings strengthen the previous evidence for SLC7A6OS as a cause of PME and highlight a founder effect in regions with migratory links to Iberia. © 2026 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.