Submissions for variant NM_005359.6(SMAD4):c.763G>T (p.Gly255Cys)

dbSNP: rs1555685930

Total submissions: 7

Submitter	RCV	SCV	Clinical significance	Condition	Last evaluated	Review status	Method	Comment
Labcorp Genetics (formerly Invitae), Labcorp	RCV000540866	SCV000632804	uncertain significance	Juvenile polyposis syndrome	2024-07-04	criteria provided, single submitter	clinical testing	This sequence change replaces glycine, which is neutral and non-polar, with cysteine, which is neutral and slightly polar, at codon 255 of the SMAD4 protein (p.Gly255Cys). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with SMAD4-related conditions. ClinVar contains an entry for this variant (Variation ID: 460565). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt SMAD4 protein function with a negative predictive value of 95%. RNA analysis performed to evaluate the impact of this missense change on mRNA splicing indicates it does not significantly alter splicing (Invitae). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance.
Ambry Genetics	RCV002311855	SCV000671977	uncertain significance	Familial thoracic aortic aneurysm and aortic dissection; Hereditary cancer-predisposing syndrome	2023-05-12	criteria provided, single submitter	clinical testing	The p.G255C variant (also known as c.763G>T), located in coding exon 5 of the SMAD4 gene, results from a G to T substitution at nucleotide position 763. The glycine at codon 255 is replaced by cysteine, an amino acid with highly dissimilar properties. This amino acid position is not well conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear.
Color Diagnostics, LLC DBA Color Health	RCV000568236	SCV001346695	uncertain significance	Hereditary cancer-predisposing syndrome	2023-12-04	criteria provided, single submitter	clinical testing	This missense variant replaces glycine with cysteine at codon 255 of the SMAD4 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with SMAD4-related disorders in the literature. This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance.
Sema4, Sema4	RCV000568236	SCV002538347	uncertain significance	Hereditary cancer-predisposing syndrome	2021-04-30	criteria provided, single submitter	curation
GeneDx	RCV002291657	SCV002584024	uncertain significance	not provided	2022-04-15	criteria provided, single submitter	clinical testing	Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge; This variant is associated with the following publications: (PMID: 18823382, 22992590, 15235019)
Baylor Genetics	RCV003476249	SCV004202595	uncertain significance	Juvenile polyposis/hereditary hemorrhagic telangiectasia syndrome	2023-06-22	criteria provided, single submitter	clinical testing
Quest Diagnostics Nichols Institute San Juan Capistrano	RCV002291657	SCV004220365	uncertain significance	not provided	2023-05-10	criteria provided, single submitter	clinical testing	This variant has not been reported in the published literature. It also has not been reported in large, multi-ethnic general populations (http://gnomad.broadinstitute.org). Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded predictions that this variant is benign. Based on the available information, we are unable to determine the clinical significance of this variant.