17-39665419-C-G

Variant names:

• chr17-39665419-C-G
• rs146502276
• NM_003673.4:c.60C>G

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BP4_Moderate BP6 BP7

The NM_003673.4(TCAP):​c.60C>G​(p.Ala20Ala) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000253 in 1,613,608 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.00031 (0 hom., cov: 32)
  • Exomes 𝑓: 0.00025 (0 hom.)
• Consequence: TCAP NM_003673.4 synonymous
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3 B:13
• Conservation: PhyloP100: 0.583
• Publications: 4 publications found

Genes affected

TCAP (HGNC:11610): (titin-cap) Sarcomere assembly is regulated by the muscle protein titin. Titin is a giant elastic protein with kinase activity that extends half the length of a sarcomere. It serves as a scaffold to which myofibrils and other muscle related proteins are attached. This gene encodes a protein found in striated and cardiac muscle that binds to the titin Z1-Z2 domains and is a substrate of titin kinase, interactions thought to be critical to sarcomere assembly. Mutations in this gene are associated with limb-girdle muscular dystrophy type 2G. [provided by RefSeq, Jul 2008]

TCAP Gene-Disease associations (from GenCC):

• autosomal recessive limb-girdle muscular dystrophy

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• hypertrophic cardiomyopathy 25

  Inheritance: AD Classification: STRONG, MODERATE, LIMITED Submitted by: Ambry Genetics, PanelApp Australia, Labcorp Genetics (formerly Invitae)
• autosomal recessive limb-girdle muscular dystrophy type 2G

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• familial isolated dilated cardiomyopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• dilated cardiomyopathy

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen
• hypertrophic cardiomyopathy

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

ACMG classification

Our verdict: Likely_benign. The variant received -4 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.42).
• BP6: Variant 17-39665419-C-G is Benign according to our data. Variant chr17-39665419-C-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 44714.
• BP7: Synonymous conserved (PhyloP=0.583 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TCAP	NM_003673.4	c.60C>G	p.Ala20Ala	synonymous_variant	Exon 1 of 2	ENST00000309889.3	NP_003664.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TCAP	ENST00000309889.3	c.60C>G	p.Ala20Ala	synonymous_variant	Exon 1 of 2	1	NM_003673.4	ENSP00000312624.2
TCAP	ENST00000578283.1	c.60C>G	p.Ala20Ala	synonymous_variant	Exon 1 of 3	5		ENSP00000462787.1

Frequencies

GnomAD3 genomes AF: 0.000309 AC: 47 AN: 152140 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000654

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.000188

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.000647

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.000291 AC: 73 AN: 251058 AF XY: 0.000243

Gnomad AFR exome AF: 0.0000616

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.000139

Gnomad NFE exome AF: 0.000599

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.000247 AC: 361 AN: 1461468 Hom.: 0 Cov.: 31 AF XY: 0.000259 AC XY: 188 AN XY: 727040

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.0000224 AC: 1 AN: 44718

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26130

East Asian (EAS) AF: 0.00 AC: 0 AN: 39694

South Asian (SAS) AF: 0.00 AC: 0 AN: 86252

European-Finnish (FIN) AF: 0.000132 AC: 7 AN: 53116

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5756

European-Non Finnish (NFE) AF: 0.000310 AC: 345 AN: 1111952

Other (OTH) AF: 0.000133 AC: 8 AN: 60372

GnomAD4 genome AF: 0.000309 AC: 47 AN: 152140 Hom.: 0 Cov.: 32 AF XY: 0.000269 AC XY: 20 AN XY: 74308

African (AFR) AF: 0.00 AC: 0 AN: 41436

American (AMR) AF: 0.0000654 AC: 1 AN: 15284

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5180

South Asian (SAS) AF: 0.00 AC: 0 AN: 4828

European-Finnish (FIN) AF: 0.000188 AC: 2 AN: 10618

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.000647 AC: 44 AN: 68002

Other (OTH) AF: 0.00 AC: 0 AN: 2092

Alfa AF: 0.000690 Hom.: 0

Bravo AF: 0.000253

EpiCase AF: 0.000382

EpiControl AF: 0.000474

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3 Benign:13

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:1 Benign:5

-

Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen

Significance: Likely benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

-

Genome Diagnostics Laboratory, University Medical Center Utrecht

Significance: Likely benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Feb 01, 2025

CeGaT Center for Human Genetics Tuebingen

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

TCAP: BP4, BP7 -

-

Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+

Significance: Likely benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Dec 15, 2016

Eurofins Ntd Llc (ga)

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

-

Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center

Significance: Likely benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

not specified Benign:6

-

PreventionGenetics, part of Exact Sciences

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jul 07, 2015

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

p.Ala20Ala in exon 1 of TCAP: This variant is not expected to have clinical sign ificance because it does not alter an amino acid residue and is not located with in the splice consensus sequence. It has been identified in 34/66232 European ch romosomes by the Exome Aggregation Consortium (ExAC, http://exac.broadinstitute. org/; dbSNP rs146502276). -

Feb 16, 2025

Laboratory of Genetics, Children's Clinical University Hospital Latvia

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Apr 06, 2015

GeneDx

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

Apr 16, 2019

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: TCAP c.60C>G alters a non-conserved nucleotide resulting in a synonymous change. 5/5 computational tools predict no significant impact on normal splicing. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 0.00029 in 251058 control chromosomes (gnomAD). The observed variant frequency is approximately 12 fold of the estimated maximal expected allele frequency for a pathogenic variant in TCAP causing Cardiomyopathy phenotype (2.5e-05), strongly suggesting that the variant is benign. Though c.60C>G has been reported in the literature in an individual affected with Dilated Cardiomyopathy (DCM), this patient also had a co-occurring pathogenic variant (TNNT2 c.629_631delAGA (p.Lys210del)) that could explain the reported phenotype, providing supporting evidence for a benign role for the variant of interest. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Six ClinVar submissions from clinical diagnostic laboratories (evaluation after 2014) cite the variant three times as likely benign, twice as uncertain significance, and once as benign. Based on the evidence outlined above, the variant was classified as benign. -

-

Clinical Genetics, Academic Medical Center

Significance: Benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Hypertrophic cardiomyopathy 25 Uncertain:1

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: 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. -

Autosomal recessive limb-girdle muscular dystrophy type 2G Uncertain:1

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: 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. -

Cardiovascular phenotype Benign:1

Nov 25, 2015

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Primary familial hypertrophic cardiomyopathy;C4225408:Hypertrophic cardiomyopathy 25 Benign:1

Jan 28, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.42
CADD	Benign	12
DANN	Benign	0.69
PhyloP100		0.58
PromoterAI		-0.071	Neutral
Mutation Taster		=95/5	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs146502276; hg19: chr17-37821672;