rs764574982

chr2-47011374-G-Achr2-47011374-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_020458.4(TTC7A):c.1331G>A(p.Arg444Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000496 in 1,612,538 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 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. R444P) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.000039 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000051 (0 hom.)
• Consequence: TTC7A NM_020458.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.64

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.07576662).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TTC7A	NM_020458.4	c.1331G>A	p.Arg444Gln	missense_variant	11/20	ENST00000319190.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TTC7A	ENST00000319190.11	c.1331G>A	p.Arg444Gln	missense_variant	11/20	2	NM_020458.4	P1

Frequencies

GnomAD3 genomes AF: 0.0000395 AC: 6 AN: 152062 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000882

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000360 AC: 9 AN: 250146 Hom.: 0 AF XY: 0.0000370 AC XY: 5 AN XY: 135296

Gnomad AFR exome AF: 0.000185

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: 0.0000528

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000507 AC: 74 AN: 1460476 Hom.: 0 Cov.: 30 AF XY: 0.0000495 AC XY: 36 AN XY: 726614

Gnomad4 AFR exome AF: 0.0000896

Gnomad4 AMR exome AF: 0.0000447

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000585

Gnomad4 OTH exome AF: 0.0000497

GnomAD4 genome AF: 0.0000395 AC: 6 AN: 152062 Hom.: 0 Cov.: 33 AF XY: 0.0000269 AC XY: 2 AN XY: 74270

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000882

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000387 Hom.: 0

Bravo AF: 0.0000680

ExAC AF: 0.0000412 AC: 5

EpiCase AF: 0.000164

EpiControl AF: 0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Multiple gastrointestinal atresias Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Apr 30, 2018

This sequence change replaces arginine with glutamine at codon 444 of the TTC7A protein (p.Arg444Gln). The arginine residue is weakly conserved and there is a small physicochemical difference between arginine and glutamine. This variant is present in population databases (rs764574982, ExAC 0.01%). This variant has not been reported in the literature in individuals with TTC7A-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The glutamine amino acid residue is found in multiple mammalian species, suggesting that this missense change does not adversely affect protein function. These predictions have not been confirmed by published functional studies and their clinical significance is uncertain. 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	0.075
BayesDel_addAF	Benign	-0.34	T
BayesDel_noAF	Benign	-0.45
Cadd	Benign	21
Dann	Uncertain	0.98
Eigen	Benign	-0.81
Eigen_PC	Benign	-0.66
FATHMM_MKL	Uncertain	0.79	D
LIST_S2	Benign	0.81	T;T;T
M_CAP	Benign	0.0073	T
MetaRNN	Benign	0.076	T;T;T
MetaSVM	Benign	-1.1	T
MutationTaster	Benign	0.99	D;D;D;D
PrimateAI	Benign	0.30	T
PROVEAN	Benign	-0.67	N;N;N
REVEL	Benign	0.050
Sift	Benign	0.48	T;T;T
Sift4G	Benign	0.15	T;T;T
Polyphen		0.013	B;B;.
Vest4		0.30
MVP		0.45
MPC		0.075
ClinPred		0.036	T
GERP RS		2.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.029
gMVP		0.35

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

Other links and lift over

dbSNP: rs764574982; hg19: chr2-47238513;