Available biochemical data suggest that these substitutions lead to less severe reduction in DHRS3 function (Figures 5, 35,44 and 6) and the associated phenotypes (pure intellectual disability in 3 siblings in family 2 [p.(Val110Ile)], apparently normal phenotypes in 2 of 3 individuals with p.(Gly115Asp), and inconsistent segregation of genotype with disease in the sib of the third individual) do not match the consistent phenotypic observations from families 1, 3, and 4. Here, DHRS3 is linked to Intellectual disability.