1-54737619-G-A

Variant names:

• chr1-54737619-G-A
• rs756617992
• NM_004623.5:c.1016G>A

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_004623.5(TTC4):​c.1016G>A​(p.Arg339Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000992 in 1,613,304 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. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000089 (0 hom.)
• Consequence: TTC4 NM_004623.5 missense
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: 0.578

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]

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]

ACMG classification

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=0.039681315).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTC4	NM_004623.5	c.1016G>A	p.Arg339Gln	missense_variant	Exon 9 of 10	ENST00000371281.4	NP_004614.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TTC4	ENST00000371281.4	c.1016G>A	p.Arg339Gln	missense_variant	Exon 9 of 10	1	NM_004623.5	ENSP00000360329.3
MROH7-TTC4	ENST00000414150.6	n.*718G>A		non_coding_transcript_exon_variant	Exon 32 of 33	2		ENSP00000410192.2
MROH7-TTC4	ENST00000414150.6	n.*718G>A		3_prime_UTR_variant	Exon 32 of 33	2		ENSP00000410192.2

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152172 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

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: 0.0000294

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.00000796 AC: 2 AN: 251130 Hom.: 0 AF XY: 0.00000737 AC XY: 1 AN XY: 135728

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: 0.0000463

Gnomad NFE exome AF: 0.00000881

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000890 AC: 13 AN: 1461132 Hom.: 0 Cov.: 30 AF XY: 0.0000110 AC XY: 8 AN XY: 726862

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: 0.0000936

Gnomad4 NFE exome AF: 0.00000540

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152172 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74336

Gnomad4 AFR AF: 0.0000241

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: 0.0000294

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000502 Hom.: 0

Bravo AF: 0.0000113

ExAC AF: 0.00000824 AC: 1

EpiCase AF: 0.00

EpiControl AF: 0.0000593

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Benign:1

Jan 31, 2025

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.073
BayesDel_addAF	Benign	-0.38	T
BayesDel_noAF	Benign	-0.78
CADD	Benign	9.9
DANN	Benign	0.79
DEOGEN2	Benign	0.0037	T
Eigen	Benign	-0.97
Eigen_PC	Benign	-0.83
FATHMM_MKL	Benign	0.52	D
LIST_S2	Benign	0.52	T
M_CAP	Benign	0.0076	T
MetaRNN	Benign	0.040	T
MetaSVM	Benign	-0.90	T
MutationAssessor	Benign	-0.15	N
PrimateAI	Benign	0.19	T
PROVEAN	Benign	0.31	N
REVEL	Benign	0.018
Sift	Benign	0.93	T
Sift4G	Benign	0.85	T
Polyphen		0.0020	B
Vest4		0.12
MVP		0.36
MPC		0.056
ClinPred		0.029	T
GERP RS		-1.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.070
gMVP		0.10

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: rs756617992; hg19: chr1-55203292;