Severe GBA1 variants drive the GBA1-PD clinical phenotype: implications for counselling and clinical trials.

Abstract

Variants in the GBA1 gene are the commonest genetic risk factor for Parkinson disease (PD). Genotype-phenotype correlations exist but with conflicting data. Here, we compared the clinical phenotype of 183 idiopathic PD (iPD) patients, 39 severe GBA1-PD, 24 mild GBA1-PD, and 55 risk GBA1-PD. Compared to iPD, we observed that only severe GBA1-PD patients had a distinctive, more several clinical profile, characterised by worse depression, hyposmia, cognitive dysfunction, and possibly constipation.