rs1444104997

Positions:

• chr7-124851908-C-T

Variant summary

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

The NM_015450.3(POT1):​c.913G>A​(p.Val305Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000131 in 152,182 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 0.000013 (0 hom., cov: 33)
• Consequence: POT1 NM_015450.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 0.210

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 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=0.05395952).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
POT1	NM_015450.3	c.913G>A	p.Val305Ile	missense_variant	11/19	ENST00000357628.8	NP_056265.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
POT1	ENST00000357628.8	c.913G>A	p.Val305Ile	missense_variant	11/19	2	NM_015450.3	ENSP00000350249	P1

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152182 Hom.: 0 Cov.: 33

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: 0.0000147

Gnomad OTH AF: 0.000478

GnomAD4 exome Cov.: 29

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152182 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 74340

Gnomad4 AFR AF: 0.00

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: 0.0000147

Gnomad4 OTH AF: 0.000478

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Mar 28, 2023

The p.V305I variant (also known as c.913G>A), located in coding exon 7 of the POT1 gene, results from a G to A substitution at nucleotide position 913. The valine at codon 305 is replaced by isoleucine, an amino acid with highly similar properties. This amino acid position is poorly conserved in available vertebrate species. 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. -

Tumor predisposition syndrome 3 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 29, 2023

This sequence change replaces valine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 305 of the POT1 protein (p.Val305Ile). 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: 541878). 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.072
BayesDel_addAF	Benign	-0.35	T
BayesDel_noAF	Benign	-0.73
CADD	Benign	6.5
DANN	Benign	0.95
DEOGEN2	Benign	0.093	T;T
Eigen	Benign	-0.90
Eigen_PC	Benign	-0.87
FATHMM_MKL	Benign	0.0098	N
LIST_S2	Benign	0.50	T;T
M_CAP	Benign	0.0060	T
MetaRNN	Benign	0.054	T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	0.20	N;.
MutationTaster	Benign	1.0	N;N
PrimateAI	Benign	0.27	T
PROVEAN	Benign	-0.21	N;N
REVEL	Benign	0.023
Sift	Benign	0.19	T;T
Sift4G	Benign	0.19	T;T
Polyphen		0.014	B;.
Vest4		0.084
MutPred		0.20		Loss of sheet (P = 0.0817);.;
MVP		0.24
MPC		0.068
ClinPred		0.046	T
GERP RS		0.91
Varity_R		0.024
gMVP		0.18

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: rs1444104997; hg19: chr7-124491962;