Genetic Variant TTC7B:p.Val658Ile (chr14-90593621-C-T) – ACMG Classification: Likely_benign (-2 pts)

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2BP4_Strong

The NM_001010854.2(TTC7B):c.1972G>A(p.Val658Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000863 in 1,598,228 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 (★).

Frequency

Genomes: 𝑓 0.00034 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000059 ( 0 hom. )

Consequence

TTC7B
NM_001010854.2 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 0.442

Variant links:

Genes affected

TTC7B (HGNC:19858): (tetratricopeptide repeat domain 7B) Involved in phosphatidylinositol phosphate biosynthetic process and protein localization to plasma membrane. Located in cytosol and plasma membrane. [provided by Alliance of Genome Resources, Apr 2022]

TTC7B links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.00928691).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTC7B	NM_001010854.2 link	c.1972G>A	p.Val658Ile	missense_variant	Exon 18 of 20	ENST00000328459.11	NP_001010854.1	Q86TV6-1Q6PIF1
TTC7B	NM_001401365.1 link	c.2185G>A	p.Val729Ile	missense_variant	Exon 20 of 22		NP_001388294.1
TTC7B	NM_001320421.2 link	c.1717G>A	p.Val573Ile	missense_variant	Exon 19 of 21		NP_001307350.1	Q86TV6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TTC7B	ENST00000328459.11 link	c.1972G>A	p.Val658Ile	missense_variant	Exon 18 of 20	1	NM_001010854.2	ENSP00000336127.4		Q86TV6-1

Frequencies

GnomAD3 genomes

AF:

0.000335

AC:

AN:

152190

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00101

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000196

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000192

Gnomad SAS

AF:

0.000414

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000294

Gnomad OTH

AF:

0.000478

GnomAD3 exomes

AF:

0.0000998

AC:

AN:

240588

Hom.:

AF XY:

0.0000923

AC XY:

AN XY:

130038

show subpopulations

Gnomad AFR exome

AF:

0.00112

Gnomad AMR exome

AF:

0.0000624

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000699

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000182

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000595

AC:

AN:

1445920

Hom.:

Cov.:

AF XY:

0.0000571

AC XY:

AN XY:

717942

show subpopulations

Gnomad4 AFR exome

AF:

0.000940

Gnomad4 AMR exome

AF:

0.0000706

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000255

Gnomad4 SAS exome

AF:

0.0000356

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000372

Gnomad4 OTH exome

AF:

0.000117

GnomAD4 genome

AF:

0.000341

AC:

AN:

152308

Hom.:

Cov.:

AF XY:

0.000309

AC XY:

AN XY:

74478

show subpopulations

Gnomad4 AFR

AF:

0.00103

Gnomad4 AMR

AF:

0.000196

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000193

Gnomad4 SAS

AF:

0.000414

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000294

Gnomad4 OTH

AF:

0.000473

Alfa

AF:

0.0000829

Hom.:

Bravo

AF:

0.000325

ESP6500AA

AF:

0.00182

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000989

AC:

EpiCase

AF:

0.0000554

EpiControl

AF:

0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Feb 15, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.1972G>A (p.V658I) alteration is located in exon 18 (coding exon 18) of the TTC7B gene. This alteration results from a G to A substitution at nucleotide position 1972, causing the valine (V) at amino acid position 658 to be replaced by an isoleucine (I). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.068

BayesDel_addAF

Benign

-0.45

BayesDel_noAF

Benign

-0.48

CADD

Benign

1.8

DANN

Benign

0.81

DEOGEN2

Benign

0.022

T;T;T

Eigen

Benign

-1.5

Eigen_PC

Benign

-1.5

FATHMM_MKL

Benign

0.14

LIST_S2

Benign

0.60

T;T;T

M_CAP

Benign

0.013

MetaRNN

Benign

0.0093

T;T;T

MetaSVM

Benign

-1.1

MutationAssessor

Benign

0.52

N;.;.

PrimateAI

Benign

0.32

PROVEAN

Benign

0.040

N;N;N

REVEL

Benign

0.033

Sift

Benign

0.66

T;T;T

Sift4G

Benign

1.0

T;T;T

Polyphen

0.0

B;.;.

Vest4

0.24

MVP

0.30

MPC

0.29

ClinPred

0.00052

GERP RS

-4.7

Varity_R

0.011

gMVP

0.14

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.050

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