Genetic Variant TTC7A:p.Arg325Trp (chr2-46994486-C-T) – ACMG Classification: Uncertain_significance (2 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_020458.4(TTC7A):c.973C>T(p.Arg325Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000235 in 1,613,860 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000023 ( 0 hom. )

Consequence

TTC7A
NM_020458.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 3.52

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:

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 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
TTC7A	NM_020458.4 link	c.973C>T	p.Arg325Trp	missense_variant	Exon 7 of 20	ENST00000319190.11	NP_065191.2	Q9ULT0-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TTC7A	ENST00000319190.11 link	c.973C>T	p.Arg325Trp	missense_variant	Exon 7 of 20	2	NM_020458.4	ENSP00000316699.5		Q9ULT0-1

Frequencies

GnomAD3 genomes

AF:

0.0000263

AC:

AN:

152104

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000483

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000207

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000796

AC:

AN:

251128

Hom.:

AF XY:

0.00000736

AC XY:

AN XY:

135788

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000176

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000233

AC:

AN:

1461756

Hom.:

Cov.:

AF XY:

0.0000234

AC XY:

AN XY:

727182

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000232

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000270

Gnomad4 OTH exome

AF:

0.0000331

GnomAD4 genome

AF:

0.0000263

AC:

AN:

152104

Hom.:

Cov.:

AF XY:

0.0000404

AC XY:

AN XY:

74308

show subpopulations

Gnomad4 AFR

AF:

0.0000483

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.000207

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000434

Hom.:

ExAC

AF:

0.00000824

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Multiple gastrointestinal atresias

Uncertain:1

Mar 28, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 325 of the TTC7A protein (p.Arg325Trp). This variant is present in population databases (rs777393270, gnomAD 0.002%). This variant has not been reported in the literature in individuals affected with TTC7A-related conditions. ClinVar contains an entry for this variant (Variation ID: 577135). 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 not expected to disrupt TTC7A protein function with a negative predictive value of 80%. 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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.15

BayesDel_addAF

Uncertain

0.055

BayesDel_noAF

Benign

-0.14

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Benign

0.046

.;T;.

Eigen

Uncertain

0.25

Eigen_PC

Uncertain

0.32

FATHMM_MKL

Uncertain

0.95

LIST_S2

Uncertain

0.94

D;D;D

M_CAP

Benign

0.036

MetaRNN

Uncertain

0.65

D;D;D

MetaSVM

Benign

-1.0

MutationAssessor

Benign

1.0

.;L;L

PrimateAI

Uncertain

0.59

PROVEAN

Benign

0.090

N;N;N

REVEL

Benign

0.18

Sift

Benign

0.18

T;T;T

Sift4G

Pathogenic

0.0010

D;D;D

Polyphen

0.17

B;D;.

Vest4

0.76

MutPred

0.45

.;Loss of disorder (P = 0.0224);Loss of disorder (P = 0.0224);

MVP

0.48

MPC

0.38

ClinPred

0.73

GERP RS

3.8

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.10

gMVP

0.41

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