Moreover, as they are not 100% penetrant features of neither DM1 nor DM2 (even if full expansions are present), we yet lack the studies which would assess all possible modifying genes and factors of cataract and infertility which can accentuate these symptoms in certain DM patients, as is the case with the abovementioned heterozygous CLCN1 variants. This evidence concerns the gene CLCN1 and Infertility.