Use of a rare disease registry for establishing phenotypic classification of previously unassignedGLAvariants: a consensus classification system by a multispecialty Fabry disease genotype-phenotype workgroup

• Type: Article in International Scientific Journal
• Date: 2020

Authors

Germain, DP (Author) Other; João Paulo Oliveira (Author) FMUP; Bichet, DG (Author) Other; Yoo, HW (Author) Other; Hopkin, RJ (Author) Other; Lemay, R (Author) Other; Politei, J (Author) Other; Wanner, C (Author) Other; Wilcox, WR (Author) Other; Warnock, DG (Author) Other

Journal

Title: Journal of Medical Genetics

Vol. 57

Pages: 542-551

ISSN: 0022-2593

Publisher: BMJ PUBLISHING GROUP

Indexing

ISI Web of Knowledge - 43 Citations

Scopus - 49 Citations

Other information

Authenticus ID: P-00R-XXG

DOI: 10.1136/jmedgenet-2019-106467

Abstract (EN): Background Fabry disease (alpha-galactosidase deficiency) is an X-linked genetic disease caused by a variety of pathogenicGLAvariants. The phenotypic heterogeneity is considerable, with two major forms, classic and later-onset disease, but adjudication of clinical phenotype is currently lacking for many variants. We aimed to determine consensus phenotypic classification for previously unclassifiedGLAvariants from theGLA-specific fabry-database.org database. Methods A Fabry disease genotype-phenotype workgroup developed a five-stage iterative system based on expert clinical assessment, published literature and clinical evidence of pathogenicity using a 2-point scoring system based on clinical hallmarks of classic disease. Kaplan-Meier (KM) analysis of severe clinical event-free survival was used as final validation. Results were compared with those from web-based disease databases and in silico pathogenicity prediction programmes. Results Final consensus on classifications of 'pathogenic' was achieved for 32 of 33GLAvariants (26 'classic' phenotype, 171 males; 6 'later-onset' phenotype, 57 males). One variant remained of uncertain significance. KM curves were similar for the known fabry-database.org database phenotypes and when workgroup consensus classifications were added, and the curves retained the same separation between 'classic' and 'later-onset' phenotypes. Conclusion The iterative system implemented by a Fabry disease genotype-phenotype workgroup achieved phenotypic classifications for variants that were previously unclassified. Clinical pathogenicity associated with a particularGLAvariant defined in affected males appears to have predictive value and also generally correlates with risk for affected females. The newly established classifications can be of benefit to the clinical care of Fabry patients harbouring these variants.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10