GBA1 and Parkinson disease: As expected, N370S/N409S and L444P/L483P, either isolated or as part of recombinant alleles, were the commonest variants with a cumulative frequency of 47.2% (N370S/N409S:30/125, 24.0% and L444P/L483P: 29/125, 23.2%, respectively) within the GBA1-PD group.