rs202044972

Positions:

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2PP3_Moderate

The NM_020458.4(TTC7A):c.2515G>A(p.Ala839Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000118 in 1,613,650 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000012 ( 0 hom. )

Consequence

TTC7A
NM_020458.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts P:1U:2

Conservation

PhyloP100: 9.96

Variant links:

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]

TTC7A links:

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]

STPG4 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 4 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.854

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TTC7A	NM_020458.4 linkuse as main transcript	c.2515G>A	p.Ala839Thr	missense_variant	20/20	ENST00000319190.11	NP_065191.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TTC7A	ENST00000319190.11 linkuse as main transcript	c.2515G>A	p.Ala839Thr	missense_variant	20/20	2	NM_020458.4	ENSP00000316699	P1	Q9ULT0-1

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152190

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000386

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000199

AC:

AN:

250996

Hom.:

AF XY:

0.0000221

AC XY:

AN XY:

135772

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000579

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad SAS exome

AF:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000882

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000116

AC:

AN:

1461342

Hom.:

Cov.:

AF XY:

0.0000124

AC XY:

AN XY:

726998

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.0000224

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000252

Gnomad4 SAS exome

AF:

0.0000232

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000630

Gnomad4 OTH exome

AF:

0.0000828

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152308

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74478

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000387

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:1Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Gastrointestinal defects and immunodeficiency syndrome 1

Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Jan 24, 2022

- -

not specified

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

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

Sep 26, 2022

Variant summary: TTC7A c.2515G>A (p.Ala839Thr) results in a non-conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 2e-05 in 250996 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.2515G>A has been reported in the literature in an individual affected with Tricho-hepato-enteric syndrome with a non-informative genotype (pathogenicity of the second allele is uncertain) (example: Neves_2018). To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. One clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 and classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Multiple gastrointestinal atresias

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 04, 2023

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. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt TTC7A protein function. ClinVar contains an entry for this variant (Variation ID: 440891). This missense change has been observed in individual(s) with gastrointestinal defects and immunodeficiency syndrome (PMID: 29174094). This variant is present in population databases (rs202044972, gnomAD 0.003%). This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 839 of the TTC7A protein (p.Ala839Thr). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.59

BayesDel_addAF

Pathogenic

0.36

BayesDel_noAF

Pathogenic

0.37

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.82

.;D;.

Eigen

Pathogenic

0.89

Eigen_PC

Pathogenic

0.82

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.96

D;D;D

M_CAP

Pathogenic

0.40

MetaRNN

Pathogenic

0.85

D;D;D

MetaSVM

Uncertain

0.74

MutationAssessor

Uncertain

2.9

.;M;.

MutationTaster

Benign

1.0

D;D;D;D

PrimateAI

Uncertain

0.76

PROVEAN

Uncertain

-2.9

D;D;D

REVEL

Pathogenic

0.83

Sift

Uncertain

0.0020

D;D;D

Sift4G

Pathogenic

0.0

D;D;D

Polyphen

1.0

D;D;.

Vest4

0.93

MVP

0.96

MPC

0.38

ClinPred

0.97

GERP RS

5.4

Varity_R

0.54

gMVP

0.71

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over