Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM1PM2PM5PP2
The NM_002880.4(RAF1):c.769T>G(p.Ser257Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S257L) has been classified as Pathogenic.
RAF1 (HGNC:9829): (Raf-1 proto-oncogene, serine/threonine kinase) This gene is the cellular homolog of viral raf gene (v-raf). The encoded protein is a MAP kinase kinase kinase (MAP3K), which functions downstream of the Ras family of membrane associated GTPases to which it binds directly. Once activated, the cellular RAF1 protein can phosphorylate to activate the dual specificity protein kinases MEK1 and MEK2, which in turn phosphorylate to activate the serine/threonine specific protein kinases, ERK1 and ERK2. Activated ERKs are pleiotropic effectors of cell physiology and play an important role in the control of gene expression involved in the cell division cycle, apoptosis, cell differentiation and cell migration. Mutations in this gene are associated with Noonan syndrome 5 and LEOPARD syndrome 2. [provided by RefSeq, Jul 2008]
Verdict is Likely_pathogenic. Variant got 7 ACMG points.
PM1
In a hotspot region, there are 8 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 8 uncertain in NM_002880.4
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr3-12604200-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 13957.Status of the report is reviewed_by_expert_panel, 3 stars.
PP2
Missense variant in gene, where missense usually causes diseases (based on misZ statistic), RAF1. . Gene score misZ 2.4628 (greater than the threshold 3.09). Trascript score misZ 3.4185 (greater than threshold 3.09). GenCC has associacion of gene with Noonan syndrome 5, dilated cardiomyopathy 1NN, Noonan syndrome with multiple lentigines, Noonan syndrome, cardiofaciocutaneous syndrome, familial isolated dilated cardiomyopathy, LEOPARD syndrome 2, Costello syndrome.