2-46956923-G-T

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM2BP4

The NM_020458.4(TTC7A):​c.433G>T​(p.Ala145Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,888 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. 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. A145T) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

TTC7A
NM_020458.4 missense

Scores

2
16

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 9.25

Publications

5 publications found
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 Gene-Disease associations (from GenCC):
  • gastrointestinal defects and immunodeficiency syndrome 1
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
  • multiple intestinal atresia
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, ClinGen, Ambry Genetics

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.28400525).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTC7ANM_020458.4 linkc.433G>T p.Ala145Ser missense_variant Exon 3 of 20 ENST00000319190.11 NP_065191.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTC7AENST00000319190.11 linkc.433G>T p.Ala145Ser missense_variant Exon 3 of 20 2 NM_020458.4 ENSP00000316699.5

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD2 exomes
AF:
0.00000795
AC:
2
AN:
251490
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000544
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000879
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000205
AC:
3
AN:
1461888
Hom.:
0
Cov.:
31
AF XY:
0.00000138
AC XY:
1
AN XY:
727246
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000180
AC:
2
AN:
1112008
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.0000000568638), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.375
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
Cov.:
33
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Multiple gastrointestinal atresias Uncertain:1
Aug 15, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 145 of the TTC7A protein (p.Ala145Ser). This variant is present in population databases (no rsID available, gnomAD 0.006%). 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: 1055896). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. 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
0.14
BayesDel_addAF
Benign
-0.16
T
BayesDel_noAF
Benign
-0.30
CADD
Benign
20
DANN
Benign
0.96
DEOGEN2
Benign
0.055
.;T;.
Eigen
Benign
0.0014
Eigen_PC
Benign
0.067
FATHMM_MKL
Uncertain
0.95
D
LIST_S2
Benign
0.83
T;T;T
M_CAP
Benign
0.021
T
MetaRNN
Benign
0.28
T;T;T
MetaSVM
Benign
-1.1
T
PhyloP100
9.3
PrimateAI
Uncertain
0.56
T
PROVEAN
Benign
-0.87
N;N;N
REVEL
Benign
0.19
Sift
Benign
0.23
T;T;T
Sift4G
Benign
0.066
T;T;T
Polyphen
0.0020
B;P;.
Vest4
0.47
MutPred
0.36
.;Gain of disorder (P = 0.0278);Gain of disorder (P = 0.0278);
MVP
0.21
MPC
0.069
ClinPred
0.67
D
GERP RS
5.8
Varity_R
0.11
gMVP
0.19
Mutation Taster
=191/109
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

Publications

Other links and lift over

dbSNP: rs201163893; hg19: chr2-47184062; API