Because the PEX6 c.1802G>A allele has a frequency of 0.41% in the European population (see ExAC Browser in the Web Resources), we expect that future WES studies will identify additional individuals who have a mild PBD due to compound heterozygosity of the PEX6 c.1802G>A allele and a severe PEX6 allele and who have not been suspected of or analyzed for a peroxisomal disorder on the basis of clinical diagnosis. The gene discussed is PEX6; the disease is peroxisomal disease.