NM_020458.4:c.2470C>T

Variant names:

• chr2-47073816-C-T
• rs1057516047
• NM_020458.4:c.2470C>T

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PVS1_Strong PM2 PP5_Moderate

The NM_020458.4(TTC7A):​c.2470C>T​(p.Gln824*) variant causes a stop gained change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: TTC7A NM_020458.4 stop_gained
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 6.15
• Publications: 0 publications found

Genes affected

TTC7A (HGNC:19750): (tetratricopeptide repeat domain 7A) This gene encodes a protein containing tetratricopeptide repeats. Mutations in this gene disrupt intestinal development and can cause early onset inflammatory bowel disease and intestinal atresia. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jun 2014]

ENSG00000273269 (HGNC:):

STPG4 (HGNC:26850): (sperm-tail PG-rich repeat containing 4) Predicted to enable chromatin binding activity and histone binding activity. Predicted to be involved in DNA demethylation of male pronucleus and positive regulation of DNA demethylation. Predicted to act upstream of or within C-5 methylation of cytosine. Predicted to be located in cytoplasm and nucleus. Predicted to be active in female pronucleus; germinal vesicle; and male pronucleus. [provided by Alliance of Genome Resources, Apr 2022]

ACMG classification

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 4 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 2-47073816-C-T is Pathogenic according to our data. Variant chr2-47073816-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 369683.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_020458.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TTC7A	NM_020458.4	MANE Select	c.2470C>T	p.Gln824*	stop_gained	Exon 20 of 20	NP_065191.2
	TTC7A	NM_001288951.2		c.2542C>T	p.Gln848*	stop_gained	Exon 21 of 21	NP_001275880.1
	TTC7A	NM_001288953.2		c.2368C>T	p.Gln790*	stop_gained	Exon 21 of 21	NP_001275882.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TTC7A	ENST00000319190.11	TSL:2 MANE Select	c.2470C>T	p.Gln824*	stop_gained	Exon 20 of 20	ENSP00000316699.5
	TTC7A	ENST00000394850.6	TSL:1	c.2542C>T	p.Gln848*	stop_gained	Exon 21 of 21	ENSP00000378320.2
	TTC7A	ENST00000409825.5	TSL:1	n.*2219C>T		non_coding_transcript_exon	Exon 21 of 21	ENSP00000386521.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Multiple gastrointestinal atresias Pathogenic:1

Sep 17, 2015

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This substitution is predicted to result in a premature stop codon at amino acid position 824, NP_065191.2: p.(Gln824*). In-silico software (MutationTaster) predicts this variant to be disease-causing. This is a novel variant, not previously reported in disease or population databases. It was identified in a homozygous state in an infant with multiple intestinal atresias. Both parents were confirmed to be carriers.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.61	D
BayesDel_noAF	Pathogenic	0.63
CADD	Pathogenic	44
DANN	Uncertain	1.0
Eigen	Pathogenic	0.84
Eigen_PC	Pathogenic	0.70
FATHMM_MKL	Pathogenic	0.97	D
PhyloP100		6.1
Vest4		0.21
GERP RS		4.5
Mutation Taster		=0/200	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs1057516047; hg19: chr2-47300955;