rs138192315

chr2-178683301-A-T

Variant summary

Our verdict is Benign. Variant got -11 ACMG points: 1P and 12B. PP3 BP6_Very_Strong BS1

The NM_001267550.2(TTN):c.32807-10T>A variant causes a splice polypyrimidine tract, intron change. The variant allele was found at a frequency of 0.000485 in 1,465,152 control chromosomes in the GnomAD database, including 9 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

• Frequency:
  • Genomes: 𝑓 0.00090 (1 hom., cov: 32)
  • Exomes 𝑓: 0.00044 (8 hom.)
• Consequence: TTN NM_001267550.2 splice_polypyrimidine_tract, intron
• Scores: Splicing: ADA: 0.9937
• Clinical Significance: Benign/Likely benign criteria provided, multiple submitters, no conflicts B:19
• Conservation: PhyloP100: 5.60

Genes affected

TTN (HGNC:12403): (titin) This gene encodes a large abundant protein of striated muscle. The product of this gene is divided into two regions, a N-terminal I-band and a C-terminal A-band. The I-band, which is the elastic part of the molecule, contains two regions of tandem immunoglobulin domains on either side of a PEVK region that is rich in proline, glutamate, valine and lysine. The A-band, which is thought to act as a protein-ruler, contains a mixture of immunoglobulin and fibronectin repeats, and possesses kinase activity. An N-terminal Z-disc region and a C-terminal M-line region bind to the Z-line and M-line of the sarcomere, respectively, so that a single titin molecule spans half the length of a sarcomere. Titin also contains binding sites for muscle associated proteins so it serves as an adhesion template for the assembly of contractile machinery in muscle cells. It has also been identified as a structural protein for chromosomes. Alternative splicing of this gene results in multiple transcript variants. Considerable variability exists in the I-band, the M-line and the Z-disc regions of titin. Variability in the I-band region contributes to the differences in elasticity of different titin isoforms and, therefore, to the differences in elasticity of different muscle types. Mutations in this gene are associated with familial hypertrophic cardiomyopathy 9, and autoantibodies to titin are produced in patients with the autoimmune disease scleroderma. [provided by RefSeq, Feb 2012]

TTN-AS1 (HGNC:44124): (TTN antisense RNA 1) This gene encodes a non-coding RNA transcribed from the opposite strand to the titin gene. [provided by RefSeq, Aug 2016]

LOC124906100 (HGNC:):

ACMG classification

Verdict is Benign. Variant got -11 ACMG points.

• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. No scorers claiming Benign.
• BP6: Variant 2-178683301-A-T is Benign according to our data. Variant chr2-178683301-A-T is described in ClinVar as [Likely_benign]. Clinvar id is 46880.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-178683301-A-T is described in Lovd as [Benign].
• BS1: Variant frequency is greater than expected in population eas. gnomad4 allele frequency = 0.000901 (137/152096) while in subpopulation EAS AF= 0.0162 (84/5186). AF 95% confidence interval is 0.0134. There are 1 homozygotes in gnomad4. There are 73 alleles in male gnomad4 subpopulation. This position pass quality control queck.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TTN	NM_001267550.2	c.32807-10T>A		splice_polypyrimidine_tract_variant, intron_variant		ENST00000589042.5
LOC124906100	XR_007087318.1	n.2186-30453A>T		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TTN	ENST00000589042.5	c.32807-10T>A		splice_polypyrimidine_tract_variant, intron_variant		5	NM_001267550.2	P1
TTN-AS1	ENST00000659121.1	n.503-51203A>T		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes AF: 0.000895 AC: 136 AN: 151978 Hom.: 1 Cov.: 32

Gnomad AFR AF: 0.00106

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000197

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.0162

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000295

Gnomad OTH AF: 0.00144

GnomAD3 exomes AF: 0.00114 AC: 146 AN: 127864 Hom.: 0 AF XY: 0.00112 AC XY: 76 AN XY: 67736

Gnomad AFR exome AF: 0.000704

Gnomad AMR exome AF: 0.000229

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0138

Gnomad SAS exome AF: 0.000235

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00143

GnomAD4 exome AF: 0.000437 AC: 574 AN: 1313056 Hom.: 8 Cov.: 20 AF XY: 0.000420 AC XY: 272 AN XY: 647446

Gnomad4 AFR exome AF: 0.000312

Gnomad4 AMR exome AF: 0.000170

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0115

Gnomad4 SAS exome AF: 0.000113

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000491

Gnomad4 OTH exome AF: 0.00264

GnomAD4 genome AF: 0.000901 AC: 137 AN: 152096 Hom.: 1 Cov.: 32 AF XY: 0.000981 AC XY: 73 AN XY: 74388

Gnomad4 AFR AF: 0.00106

Gnomad4 AMR AF: 0.000196

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.0162

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000295

Gnomad4 OTH AF: 0.00190

Alfa AF: 0.000299 Hom.: 0

Bravo AF: 0.000971

Asia WGS AF: 0.00954 AC: 33 AN: 3472

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:19

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Benign:7

Likely benign, criteria provided, single submitter	clinical testing	PreventionGenetics, part of Exact Sciences	-	- -
Likely benign, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Jun 24, 2015	c.29075-10T>A in intron 130 of TTN: This variant is not expected to have clinica l significance because it has been identified in 2.2% (14/644) of East Asian chr omosomes by the Exome Aggregation Consortium (ExAC, http://exac.broadinstitute.o rg; dbSNP rs138192315). -
Benign, no assertion criteria provided	clinical testing	Clinical Genetics, Academic Medical Center	-	- -
Benign, criteria provided, single submitter	clinical testing	GeneDx	Mar 19, 2014	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. -
Benign, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Apr 15, 2021	- -
Benign, no assertion criteria provided	clinical testing	Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+	-	- -
Benign, no assertion criteria provided	clinical testing	Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center	-	- -

Autosomal recessive limb-girdle muscular dystrophy type 2J Benign:2

Likely benign, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Jan 12, 2018	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. -
Benign, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Sep 10, 2021	- -

Early-onset myopathy with fatal cardiomyopathy Benign:2

Likely benign, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Jan 12, 2018	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. -
Benign, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Sep 10, 2021	- -

Myopathy, myofibrillar, 9, with early respiratory failure Benign:2

Benign, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Jan 12, 2018	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 benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -
Benign, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Sep 10, 2021	- -

Tibial muscular dystrophy Benign:2

Benign, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Jan 12, 2018	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 benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -
Benign, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Sep 10, 2021	- -

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Benign:1

Benign, criteria provided, single submitter

clinical testing

Invitae

Jan 31, 2024

- -

Cardiomyopathy Benign:1

Benign, criteria provided, single submitter

clinical testing

CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario

May 04, 2018

- -

Dilated cardiomyopathy 1G Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

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. -

not provided Benign:1

Benign, criteria provided, single submitter

clinical testing

Athena Diagnostics

Apr 19, 2018

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.15
Cadd	Uncertain	23
Dann	Benign	0.83

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	0.99
dbscSNV1_RF	Pathogenic	0.74
SpliceAI score (max)		0.43		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.43		Position offset: -10

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

Publications

LitVar

Other links and lift over

dbSNP: rs138192315; hg19: chr2-179548028;