Submissions for variant NM_000256.3(MYBPC3):c.2210C>T (p.Thr737Met)

gnomAD frequency: 0.00016  dbSNP: rs199893357

Total submissions: 10

Submitter	RCV	SCV	Clinical significance	Condition	Last evaluated	Review status	Method	Comment
Biesecker Lab/Clinical Genomics Section, National Institutes of Health	RCV000172009	SCV000054766	uncertain significance	not provided	2013-06-24	criteria provided, single submitter	research
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	RCV000035476	SCV000059124	uncertain significance	not specified	2011-07-28	criteria provided, single submitter	clinical testing	The Thr737Met variant in MYBPC3 has not been reported in the literature though i t has been identified in 1 individual with HCM out of >1900 Caucasian probands ( 3800 chromosomes) tested by our laboratory. This low frequency is consistent wit h a pathogenic role. However, threonine (Thr) at position 737 is not completely conserved in evolution, suggesting that a change may be tolerated. Furthermore, this variant was predicted to be benign using a novel computational tool, which was validated by our laboratory using a set of cardiomyopathy variants with well -established clinical significance. This tool's benign interpretation is estimat ed to be correct 89% of the time, which suggests but does not prove that this va riant is benign (Jordan 2011). In summary, the clinical significance of this var iant cannot be determined without additional studies.
GeneDx	RCV000172009	SCV000208079	uncertain significance	not provided	2023-07-06	criteria provided, single submitter	clinical testing	Reported in association with HCM and DCM; however, this variant is also observed in individuals with no known history of cardiomyopathy (Walsh et al., 2017; Mazzarotto et al., 2020; Bick et al., 2012; Ng et al., 2013; Thompson et al., 2021); In silico analysis supports that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 22958901, 23861362, 21310275, 31983221, 32746448, 27532257, 33782553)
Invitae	RCV000558691	SCV000623548	uncertain significance	Hypertrophic cardiomyopathy	2024-01-31	criteria provided, single submitter	clinical testing	This sequence change replaces threonine, which is neutral and polar, with methionine, which is neutral and non-polar, at codon 737 of the MYBPC3 protein (p.Thr737Met). This variant is present in population databases (rs199893357, gnomAD 0.01%). This missense change has been observed in individuals with clinical features of MYBPC3-related conditions (PMID: 27532257, 31983221, 32746448, 33782553; Invitae). ClinVar contains an entry for this variant (Variation ID: 42608). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. 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.
Illumina Laboratory Services, Illumina	RCV001103119	SCV001259837	likely benign	Left ventricular noncompaction 10	2018-01-12	criteria provided, single submitter	clinical testing	This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease.
Illumina Laboratory Services, Illumina	RCV001103120	SCV001259838	uncertain significance	Hypertrophic cardiomyopathy 4	2018-01-12	criteria provided, single submitter	clinical testing	This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease.
Color Diagnostics, LLC DBA Color Health	RCV001180297	SCV001345191	uncertain significance	Cardiomyopathy	2023-11-20	criteria provided, single submitter	clinical testing	This missense variant replaces threonine with methionine at codon 737 of the MYBPC3 protein. Computational prediction suggests that this variant may have a neutral impact protein structure and function. To our knowledge, functional studies have not been reported for this variant. This variant has been reported in five individuals affected with hypertrophic cardiomyopathy (PMID: 27532257, 32841044, 33495597). This variant has also been reported in two individuals affected with dilated cardiomyopathy (PMID: 31983221 and 32746448). This variant has also been identified in 21/280356 chromosomes 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.
CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario	RCV001180297	SCV002042155	uncertain significance	Cardiomyopathy	2021-05-31	criteria provided, single submitter	clinical testing
Mayo Clinic Laboratories, Mayo Clinic	RCV000172009	SCV004226159	uncertain significance	not provided	2022-02-10	criteria provided, single submitter	clinical testing	BP4
Stanford Center for Inherited Cardiovascular Disease, Stanford University	RCV000035476	SCV000280233	uncertain significance	not specified	2014-01-31	no assertion criteria provided	clinical testing	Note this variant was found in clinical genetic testing performed by one or more labs who may also submit to ClinVar. Thus any internal case data may overlap with the internal case data of other labs. The interpretation reviewed below is that of the Stanford Center for Inherited Cardiovascular Disease. p.Thr737Met in MYBPC3 The p.Thr737Met variant is novel. The c.2210C>T substitution was identified in exon 23 of MYBPC3, resulting in a non-conservative amino acid substitution of a polar neutral threonine with non-polar neutral methionine. The threonine residue is conserved across other mammalian species. In silico analysis with PolyPhen2 predicts the variant to be probably damaging. A variant has been reported in association with HCM at a nearby codon (p.Arg733Cys, Van Driest et al 2004). In total the variant has not been seen in ~4 of ~7,134 laboratory controls and individuals from publicly available population datasets. The variant was recently reported online in 2 of 4197 Caucasian individuals and 0 of 2077 African-American individuals in the NHLBI Exome Sequencing Project dataset (as of April 9th, 2012). The phenotype of those individuals is not publicly available, however the cohorts that were merged to create this dataset were all either general population samples or samples recruited for common cardiovascular disease such as hypertension. Of note, other variants with strong evidence for pathogenicity have been seen in this dataset at a similar frequency, so this does not necessarily mean that the variant is not pathogenic. The variant is also listed in dbSNP (rs199893357) with note that it was observed in 2 of ~560 individuals in the NHGRI ClinSeq cohort. 1000 genomes lists the variant, but only in reference to the dbSNP entry. The p.Thr737Met variant was not detected in up to 300 individuals of Caucasian and African American ancestry tested at GeneDx. The pathogenicity of this novel variant is currently uncertain. It may contribute to the patient’s cardiomyopathy or it may be a rare benign variant.