Submissions for variant NM_000249.4(MLH1):c.1775G>A (p.Ser592Asn)

dbSNP: rs587782621

Total submissions: 7

Submitter	RCV	SCV	Clinical significance	Condition	Last evaluated	Review status	Method	Comment
Invitae	RCV000204209	SCV000260157	uncertain significance	Hereditary nonpolyposis colorectal neoplasms	2023-03-04	criteria provided, single submitter	clinical testing	Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. 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 MLH1 protein function. ClinVar contains an entry for this variant (Variation ID: 219961). This variant has not been reported in the literature in individuals affected with MLH1-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces serine, which is neutral and polar, with asparagine, which is neutral and polar, at codon 592 of the MLH1 protein (p.Ser592Asn). 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.
GeneDx	RCV000213242	SCV000279749	uncertain significance	not provided	2021-09-27	criteria provided, single submitter	clinical testing	Not observed at significant frequency in large population cohorts (Lek 2016); 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: 22753075, 20533529, 12799449)
Color Diagnostics, LLC DBA Color Health	RCV000581549	SCV000689840	uncertain significance	Hereditary cancer-predisposing syndrome	2023-04-06	criteria provided, single submitter	clinical testing	This missense variant replaces serine with asparagine at codon 592 of the MLH1 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 MLH1-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.
Fulgent Genetics, Fulgent Genetics	RCV000764495	SCV000895566	uncertain significance	Mismatch repair cancer syndrome 1; Muir-Torré syndrome; Colorectal cancer, hereditary nonpolyposis, type 2	2018-10-31	criteria provided, single submitter	clinical testing
Ambry Genetics	RCV000581549	SCV001173644	uncertain significance	Hereditary cancer-predisposing syndrome	2023-07-26	criteria provided, single submitter	clinical testing	The p.S592N variant (also known as c.1775G>A), located in coding exon 16 of the MLH1 gene, results from a G to A substitution at nucleotide position 1775. The serine at codon 592 is replaced by asparagine, an amino acid with highly similar properties. This amino acid position is not well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear.
Women's Health and Genetics/Laboratory Corporation of America, LabCorp	RCV003401106	SCV004122916	uncertain significance	not specified	2023-10-16	criteria provided, single submitter	clinical testing	Variant summary: MLH1 c.1775G>A (p.Ser592Asn) results in a conservative amino acid change located in the DNA mismatch repair protein Mlh1, C-terminal domain (IPR032189) of the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant was absent in 251258 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.1775G>A has been reported in the literature in at-least one individual affected with colorectal cancer in whom MLH1 promoter hypermethylation was detected supporting a sporadic etiology of disease (example, Wang_2019). These report(s) do not provide unequivocal conclusions about the germline association of the variant with Lynch Syndrome. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication has been ascertained in the context of this evaluation (PMID: 30723297). Five submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. All submitters classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance.
All of Us Research Program, National Institutes of Health	RCV003997598	SCV004843213	uncertain significance	Lynch syndrome	2023-05-04	criteria provided, single submitter	clinical testing	This missense variant replaces serine with asparagine at codon 592 of the MLH1 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 MLH1-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.