2-74483378-A-G

Variant names:

• chr2-74483378-A-G
• rs749850269
• NM_022492.6:c.97A>G

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_022492.6(TTC31):​c.97A>G​(p.Lys33Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000372 in 1,614,030 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/22 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. K33Q) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: TTC31 NM_022492.6 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.375
• Publications: 0 publications found

Genes affected

TTC31 (HGNC:25759): (tetratricopeptide repeat domain 31)

CCDC142 (HGNC:25889): (coiled-coil domain containing 142)

ACMG classification

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.12840983).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTC31	NM_022492.6	c.97A>G	p.Lys33Glu	missense_variant	Exon 2 of 13	ENST00000233623.11	NP_071937.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TTC31	ENST00000233623.11	c.97A>G	p.Lys33Glu	missense_variant	Exon 2 of 13	1	NM_022492.6	ENSP00000233623.6

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152138 Hom.: 0 Cov.: 32

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: 0.0000441

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.00000801 AC: 2 AN: 249588 AF XY: 0.00000738

Gnomad AFR exome AF: 0.0000646

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000883

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461892 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727246

African (AFR) AF: 0.0000299 AC: 1 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 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: 1112010

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152138 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74322

African (AFR) AF: 0.00 AC: 0 AN: 41432

American (AMR) AF: 0.00 AC: 0 AN: 15274

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5194

South Asian (SAS) AF: 0.00 AC: 0 AN: 4830

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10610

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000441 AC: 3 AN: 68010

Other (OTH) AF: 0.00 AC: 0 AN: 2090

Alfa AF: 0.0000282 Hom.: 0

Bravo AF: 0.0000189

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Dec 15, 2021

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.97A>G (p.K33E) alteration is located in exon 2 (coding exon 2) of the TTC31 gene. This alteration results from a A to G substitution at nucleotide position 97, causing the lysine (K) at amino acid position 33 to be replaced by a glutamic acid (E). 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	0.11
BayesDel_addAF	Benign	-0.18	T
BayesDel_noAF	Benign	-0.31
CADD	Benign	17
DANN	Uncertain	0.99
DEOGEN2	Benign	0.0077	.;.;T
Eigen	Benign	-0.39
Eigen_PC	Benign	-0.39
FATHMM_MKL	Benign	0.14	N
LIST_S2	Benign	0.70	T;T;T
M_CAP	Benign	0.0062	T
MetaRNN	Benign	0.13	T;T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	1.8	L;.;L
PhyloP100		-0.38
PrimateAI	Benign	0.26	T
PROVEAN	Uncertain	-3.3	D;N;N
REVEL	Benign	0.053
Sift	Pathogenic	0.0	D;D;D
Sift4G	Uncertain	0.023	D;D;D
Polyphen		0.44	.;.;B
Vest4		0.40
MutPred		0.28		Loss of methylation at K33 (P = 8e-04);Loss of methylation at K33 (P = 8e-04);Loss of methylation at K33 (P = 8e-04);
MVP		0.57
MPC		0.15
ClinPred		0.62	D
GERP RS		-1.7
PromoterAI		0.074	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.35
gMVP		0.16
Mutation Taster		=99/1	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

Other links and lift over

dbSNP: rs749850269; hg19: chr2-74710505;