rs1554414706

chr7-124824048-T-C

Variant summary

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

The NM_015450.3(POT1):c.1819A>G(p.Ile607Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 13/21 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. I607T) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: POT1 NM_015450.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 2.48

Genes affected

POT1 (HGNC:17284): (protection of telomeres 1) This gene is a member of the telombin family and encodes a nuclear protein involved in telomere maintenance. Specifically, this protein functions as a member of a multi-protein complex that binds to the TTAGGG repeats of telomeres, regulating telomere length and protecting chromosome ends from illegitimate recombination, catastrophic chromosome instability, and abnormal chromosome segregation. Increased transcriptional expression of this gene is associated with stomach carcinogenesis and its progression. Alternatively spliced transcript variants have been described. [provided by RefSeq, Jul 2008]

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=0.17150125).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
POT1	NM_015450.3	c.1819A>G	p.Ile607Val	missense_variant	19/19	ENST00000357628.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
POT1	ENST00000357628.8	c.1819A>G	p.Ile607Val	missense_variant	19/19	2	NM_015450.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Tumor predisposition syndrome 3 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Nov 25, 2023

This sequence change replaces isoleucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 607 of the POT1 protein (p.Ile607Val). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with POT1-related conditions. ClinVar contains an entry for this variant (Variation ID: 541862). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt POT1 protein function with a negative predictive value of 80%. 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. -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Feb 19, 2023

The p.I607V variant (also known as c.1819A>G), located in coding exon 15 of the POT1 gene, results from an A to G substitution at nucleotide position 1819. The isoleucine at codon 607 is replaced by valine, an amino acid with highly similar properties. This amino acid position is conserved. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, 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	-0.070	T
BayesDel_noAF	Benign	-0.34
Cadd	Benign	20
Dann	Uncertain	0.99
DEOGEN2	Benign	0.17	T;T
Eigen	Benign	-0.14
Eigen_PC	Benign	-0.011
FATHMM_MKL	Uncertain	0.85	D
LIST_S2	Benign	0.78	T;T
M_CAP	Benign	0.0091	T
MetaRNN	Benign	0.17	T;T
MetaSVM	Benign	-0.83	T
MutationAssessor	Uncertain	2.8	M;.
MutationTaster	Benign	0.69	N;N
PrimateAI	Benign	0.46	T
PROVEAN	Benign	-0.40	N;N
REVEL	Benign	0.075
Sift	Uncertain	0.015	D;D
Sift4G	Uncertain	0.060	T;T
Polyphen		0.011	B;.
Vest4		0.48
MutPred		0.25		Gain of methylation at K608 (P = 0.0526);.;
MVP		0.41
MPC		0.072
ClinPred		0.82	D
GERP RS		3.5
Varity_R		0.11
gMVP		0.33

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: rs1554414706; hg19: chr7-124464102;