AUTHOR=Ghorbani Fatemeh , Alimohamed Mohamed Z. , Vilacha Juliana F. , Van Dijk Krista K. , De Boer-Bergsma Jelkje , Fokkens Michiel R. , Lemmink Henny , Sijmons Rolf H. , Sikkema-Raddatz Birgit , Groves Matthew R. , Verschuuren-Bemelmans Corien C. , Verbeek Dineke S. , Van Diemen Cleo C. , Westers Helga TITLE=Feasibility of Follow-Up Studies and Reclassification in Spinocerebellar Ataxia Gene Variants of Unknown Significance JOURNAL=Frontiers in Genetics VOLUME=13 YEAR=2022 URL=https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2022.782685 DOI=10.3389/fgene.2022.782685 ISSN=1664-8021 ABSTRACT=

Spinocerebellar ataxia (SCA) is a heterogeneous group of neurodegenerative disorders with autosomal dominant inheritance. Genetic testing for SCA leads to diagnosis, prognosis and risk assessment for patients and their family members. While advances in sequencing and computing technologies have provided researchers with a rapid expansion in the genetic test content that can be used to unravel the genetic causes that underlie diseases, the large number of variants with unknown significance (VUSes) detected represent challenges. To minimize the proportion of VUSes, follow-up studies are needed to aid in their reclassification as either (likely) pathogenic or (likely) benign variants. In this study, we addressed the challenge of prioritizing VUSes for follow-up using (a combination of) variant segregation studies, 3D protein modeling, in vitro splicing assays and functional assays. Of the 39 VUSes prioritized for further analysis, 13 were eligible for follow up. We were able to reclassify 4 of these VUSes to LP, increasing the molecular diagnostic yield by 1.1%. Reclassification of VUSes remains difficult due to limited possibilities for performing variant segregation studies in the classification process and the limited availability of routine functional tests.