chr17-39666065-C-A

Variant names:

• chr17-39666065-C-A
• rs755539784
• NM_003673.4:c.460C>A

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_003673.4(TCAP):​c.460C>A​(p.Arg154Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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. R154H) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: TCAP NM_003673.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 2.24
• Publications: 2 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: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TCAP	NM_003673.4	c.460C>A	p.Arg154Ser	missense_variant	Exon 2 of 2	ENST00000309889.3	NP_003664.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TCAP	ENST00000309889.3	c.460C>A	p.Arg154Ser	missense_variant	Exon 2 of 2	1	NM_003673.4	ENSP00000312624.2
TCAP	ENST00000578283.1	c.388C>A	p.Arg130Ser	missense_variant	Exon 3 of 3	5		ENSP00000462787.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:2

Feb 21, 2024

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: 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 -

Jun 27, 2017

Eurofins Ntd Llc (ga)

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Cardiovascular phenotype Uncertain:1

Feb 15, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.460C>A (p.R154S) alteration is located in exon 2 (coding exon 2) of the TCAP gene. This alteration results from a C to A substitution at nucleotide position 460, causing the arginine (R) at amino acid position 154 to be replaced by a serine (S). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.43
BayesDel_addAF	Uncertain	0.090	D
BayesDel_noAF	Benign	-0.11
CADD	Uncertain	24
DANN	Benign	0.92
DEOGEN2	Uncertain	0.68	D;.
Eigen	Benign	-0.090
Eigen_PC	Benign	0.098
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Benign	0.65	T;T
M_CAP	Uncertain	0.20	D
MetaRNN	Uncertain	0.44	T;T
MetaSVM	Benign	-0.29	T
MutationAssessor	Uncertain	2.0	M;.
PhyloP100		2.2
PrimateAI	Uncertain	0.51	T
PROVEAN	Uncertain	-2.4	N;.
REVEL	Uncertain	0.43
Sift	Uncertain	0.0090	D;.
Sift4G	Uncertain	0.013	D;D
Polyphen		0.12	B;.
Vest4		0.22
MutPred		0.60		Gain of phosphorylation at R154 (P = 0.0147);.;
MVP		0.97
MPC		0.63
ClinPred		0.82	D
GERP RS		5.8
Varity_R		0.28
gMVP		0.51
Mutation Taster		=58/42	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: rs755539784; hg19: chr17-37822318;