MRC1 and Leigh syndrome: Furthermore, while 77% of those with MMR deficiencies received genetic counseling at our institution, a prior study by Lee et al. at New York University showed only 58% of women with high-risk characteristics for LS, such as age < 50 at the time of diagnosis, two or more family members with LS cancers, a metachronous or synchronous LS cancer, or evidence of MMR loss on IHC, were referred for genetic counseling [3].