MLH1 and Lynch syndrome: On the other hand, Lynch syndrome is an autosomal dominant disorder in which several genes are mutated, namely MutL homolog 1 (MLH1) (50%), MutS homolog 2 (MSH2) (40%), MutS homolog 6 (MSH6) (7–10%), and PMS1 homolog 2 (PMS2) (5%) [14], conferring a higher risk of developing multiple types of cancer [15].