Some cases of POI are syndromic, where the POI phenotype accompanies a specific disease, such as Turner’s syndrome, Fragile X syndrome, galactosemia (due to variants in the GALT gene), BPES (blepharophimosis, ptosis, epicanthus inversus syndrome, due to genetic variants in FOXL2), and ataxiatelangiectasia (due to variants in the ATM gene). This evidence concerns the gene GALT and classic galactosemia.