Genetic Variant TTC4:p.Asp112Gly (chr1-54717597-A-G) – ACMG Classification: Uncertain_significance (2 pts)

Variant summary

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

The NM_004623.5(TTC4):c.335A>G(p.Asp112Gly) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,459,840 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000027 ( 0 hom. )

Consequence

TTC4
NM_004623.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 8.34

Variant links:

Genes affected

TTC4 (HGNC:12394): (tetratricopeptide repeat domain 4) This gene encodes a protein that contains tetratricopeptide (TPR) repeats, which often mediate protein-protein interactions and chaperone activity. The encoded protein interacts with heat shock proteins 70 and 90. Alternative splicing results in multiple transcript variants. Naturally-occuring readthrough transcription occurs from upstream gene MROH (maestro heat-like repeat family member 7) to this gene. [provided by RefSeq, Apr 2014]

TTC4 links:

MROH7-TTC4 (HGNC:49180): (MROH7-TTC4 readthrough (NMD candidate)) This locus represents naturally occurring read-through transcription between the neighboring MROH7 (maestro heat-like repeat family member 7) and TTC4 (tetratricopeptide repeat domain 4) genes. Alternative splicing results in multiple transcript variants, which are candidates for nonsense-mediated mRNA decay (NMD) and are unlikely to produce protein products. [provided by RefSeq, Aug 2013]

MROH7-TTC4 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
TTC4	NM_004623.5 link	c.335A>G	p.Asp112Gly	missense_variant	Exon 3 of 10	ENST00000371281.4	NP_004614.3	O95801

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
TTC4	ENST00000371281.4 link	c.335A>G	p.Asp112Gly	missense_variant	Exon 3 of 10	1	NM_004623.5	ENSP00000360329.3	O95801
MROH7-TTC4	ENST00000414150.6 link	n.*37A>G		non_coding_transcript_exon_variant	Exon 26 of 33	2		ENSP00000410192.2	A0A0A0MT08
MROH7-TTC4	ENST00000414150.6 link	n.*37A>G		3_prime_UTR_variant	Exon 26 of 33	2		ENSP00000410192.2	A0A0A0MT08

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000401

AC:

AN:

249384

Hom.:

AF XY:

0.00000742

AC XY:

AN XY:

134844

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000546

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000274

AC:

AN:

1459840

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

726114

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000504

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.0000332

GnomAD4 genome

Cov.:

Bravo

AF:

0.0000113

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Sep 29, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.335A>G (p.D112G) alteration is located in exon 3 (coding exon 3) of the TTC4 gene. This alteration results from a A to G substitution at nucleotide position 335, causing the aspartic acid (D) at amino acid position 112 to be replaced by a glycine (G). 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

Uncertain

0.38

BayesDel_addAF

Benign

-0.064

BayesDel_noAF

Benign

-0.16

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Benign

0.10

Eigen

Uncertain

0.46

Eigen_PC

Uncertain

0.40

FATHMM_MKL

Uncertain

0.96

LIST_S2

Uncertain

0.90

M_CAP

Benign

0.029

MetaRNN

Uncertain

0.65

MetaSVM

Benign

-0.56

MutationAssessor

Uncertain

2.6

PrimateAI

Benign

0.43

PROVEAN

Pathogenic

-5.2

REVEL

Uncertain

0.37

Sift

Uncertain

0.010

Sift4G

Benign

0.13

Polyphen

0.93

Vest4

0.52

MVP

0.88

MPC

0.35

ClinPred

0.97

GERP RS

2.8

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.19

gMVP

0.61

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.22

Details are displayed if max score is > 0.2

DS_DG_spliceai

0.22

Position offset: -1

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