17-39666078-G-A
Variant summary
Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM5
The NM_003673.4(TCAP):c.473G>A(p.Arg158His) variant causes a missense change. The variant allele was found at a frequency of 0.00000749 in 1,602,042 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R158C) has been classified as Likely pathogenic.
Frequency
Consequence
NM_003673.4 missense
Scores
Clinical Significance
Conservation
Publications
- autosomal recessive limb-girdle muscular dystrophyInheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
- hypertrophic cardiomyopathy 25Inheritance: AD Classification: STRONG, MODERATE, LIMITED Submitted by: Ambry Genetics, PanelApp Australia, Labcorp Genetics (formerly Invitae)
- autosomal recessive limb-girdle muscular dystrophy type 2GInheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Ambry Genetics, Labcorp Genetics (formerly Invitae)
- familial isolated dilated cardiomyopathyInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- dilated cardiomyopathyInheritance: AD Classification: LIMITED Submitted by: ClinGen
- hypertrophic cardiomyopathyInheritance: AD Classification: NO_KNOWN Submitted by: ClinGen
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ACMG classification
Our verdict: Uncertain_significance. The variant received 2 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000197 AC: 3AN: 152180Hom.: 0 Cov.: 33 show subpopulations
GnomAD2 exomes AF: 0.00000828 AC: 2AN: 241542 AF XY: 0.00000760 show subpopulations
GnomAD4 exome AF: 0.00000621 AC: 9AN: 1449862Hom.: 0 Cov.: 34 AF XY: 0.00000416 AC XY: 3AN XY: 721654 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000197 AC: 3AN: 152180Hom.: 0 Cov.: 33 AF XY: 0.0000135 AC XY: 1AN XY: 74340 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
not specified Uncertain:1
The Arg158His variant (TCAP) has not been previously reported but has been ident ified by our laboratory in 1 individual with a family history of sudden death of unknown etiology. Computational analyses (biochemical amino acid properties, co nservation, AlignGVGD, PolyPhen2, and SIFT) suggest that this variant may impact the protein, though this information is not predictive enough to determine path ogenicity. Of note, a different variant at the same position (Arg158Ser, unknown significance) has been detected by our laboratory in an individual with DCM. A dditional information is needed to fully assess the clinical significance of the Arg158His variant. -
not provided Uncertain:1
Not observed at significant frequency in large population cohorts (gnomAD); Missense variants in this gene are a common cause of disease and they are underrepresented in the general population; In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge; This variant is associated with the following publications: (PMID: 16490376) -
Cardiovascular phenotype Uncertain:1
The p.R158H variant (also known as c.473G>A), located in coding exon 2 of the TCAP gene, results from a G to A substitution at nucleotide position 473. The arginine at codon 158 is replaced by histidine, an amino acid with highly similar properties. Other alterations affecting this amino acid (p.R158C, c.472C>T and p.R158S, c.472C>A) have been detected in dilated cardiomyopathy cohorts; however, clinical details were limited (Hirtle-Lewis M et al. Clin Cardiol. 2013;36:628-33; Akinrinade O et al. Eur Heart J. 2015;36:2327-37). This amino acid position is highly 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. -
Primary familial hypertrophic cardiomyopathy;C4225408:Hypertrophic cardiomyopathy 25 Uncertain:1
This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 158 of the TCAP protein (p.Arg158His). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This variant has not been reported in the literature in individuals affected with TCAP-related conditions. ClinVar contains an entry for this variant (Variation ID: 44712). 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 disruptive. This variant disrupts the p.Arg158 amino acid residue in TCAP. Other variant(s) that disrupt this residue have been observed in individuals with TCAP-related conditions (Invitae), which suggests that this may be a clinically significant amino acid residue. 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. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at