ARSA and nervous system disorder: In conclusion, this comprehensive literature review, our data and the presented two long‐term follow‐ups decipher that the association of low ARSA activity and any neurological disease feature needs to be questioned critically, especially due to the high prevalence of heterozygous disease‐causing variants in the ARSA gene and PD alleles in the general population according to gnomAD,51 leading to reduced enzyme activity.