ARSA and leukodystrophy: To explore whether lower leukodystrophy gene allele frequencies in nonwhite races might account for lower diagnosis rates, we determined the frequency of missense and loss-of-function alleles in ABCD1, ARSA, GALC, and IDUA (Figure) using the gnomAD database.16 We observed similar or higher frequencies of missense or loss-of-function alleles in populations of Latino and African descent.