KRAS and intellectual disability-hypotonic facies syndrome, X-linked, 1: Rarer genetic variants, such as KRAS c.351A > C (p.Lys117Asn, K117N) (7) and c.436G > A, (p.Ala146Thr, A146T) (28, 42), identified in patients with SFMS, have also been previously described as mutations associated with the actively proliferating cell phenotype (52).