Compound heterozygosity for NM_000179.3:c.3226C>T in the MSH6 gene has been reported in the literature in three unrelated cases and two sisters with constitutional mismatch repair cancer syndrome (Okkels et al., 2006; Plaschke et al., 2006; Rahner et al., 2008; Jasperson et al., 2011). The gene discussed is MSH6; the disease is mismatch repair cancer syndrome.