Our verdict is Uncertain significance. Variant got 3 ACMG points: 5P and 2B. PM1PM2PP2BP4_Moderate
The NM_002880.4(RAF1):c.892A>C(p.Asn298His) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).
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 Uncertain_significance. Variant got 3 ACMG points.
PM1
In a region_of_interest Disordered (size 114) in uniprot entity RAF1_HUMAN there are 15 pathogenic changes around while only 3 benign (83%) in NM_002880.4
PM2
Very rare variant in population databases, with high coverage;
PP2
Missense variant in the RAF1 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 47 curated pathogenic missense variants (we use a threshold of 10). The gene has 39 curated benign missense variants. Gene score misZ: 2.4628 (below the threshold of 3.09). Trascript score misZ: 3.4185 (above the threshold of 3.09). GenCC associations: The gene is linked to Noonan syndrome 5, dilated cardiomyopathy 1NN, Noonan syndrome with multiple lentigines, Noonan syndrome, cardiofaciocutaneous syndrome, familial isolated dilated cardiomyopathy, LEOPARD syndrome 2, Costello syndrome.
BP4
Computational evidence support a benign effect (MetaRNN=0.23025379).
Review Status: criteria provided, single submitter
Collection Method: clinical testing
In summary, this is a novel missense change that is not predicted to affect protein function or cause disease. However the evidence is insufficient at this time to prove that conclusively. It has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but these predictions have not been confirmed by published functional studies. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a RAF1-related disease. This sequence change replaces asparagine with histidine at codon 298 of the RAF1 protein (p.Asn298His). The asparagine residue is moderately conserved and there is a small physicochemical difference between asparagine and histidine. -