7-124851905-T-C

Position:

• chr7-124851905-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.916A>G​(p.Ile306Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,459,378 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 Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: POT1 NM_015450.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3 B:3
• Conservation: PhyloP100: -0.555

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]

POT1 (HGNC:):

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=0.06801072).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
POT1	NM_015450.3	c.916A>G	p.Ile306Val	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.916A>G	p.Ile306Val	missense_variant	11/19	2	NM_015450.3	ENSP00000350249.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000796 AC: 2 AN: 251102 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135736

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: 0.00

Gnomad NFE exome AF: 0.0000176

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1459378 Hom.: 0 Cov.: 29 AF XY: 0.00000138 AC XY: 1 AN XY: 726196

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000360

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Alfa AF: 0.0000468 Hom.: 0

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3 Benign:3

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not specified Uncertain:1 Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	Genetic Services Laboratory, University of Chicago	Jan 11, 2021	DNA sequence analysis of the POT1 gene demonstrated a sequence change, c.916A>G, in exon 11 that results in an amino acid change, p.Ile306Val. This sequence change does not appear to have been previously described in individuals with POT1-related disorders and has been described in the gnomAD database in two individuals with an overall population frequency of 0.0008% (dbSNP rs1415345156). The p.Ile306Val change affects a moderately conserved amino acid residue located in a domain of the POT1 protein that is not known to be functional. The p.Ile306Val substitution appears to be benign using several in-silico pathogenicity prediction tools (SIFT, PolyPhen2, Align GVGD, REVEL). Due to these contrasting evidences and the lack of functional studies, the clinical significance of the p.Ile306Val change remains unknown at this time. -
Likely benign, criteria provided, single submitter	clinical testing	Center for Genomic Medicine, Rigshospitalet, Copenhagen University Hospital	Jul 31, 2024	- -

not provided Benign:2

Likely benign, no assertion criteria provided	clinical testing	Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center	-	- -
Likely benign, no assertion criteria provided	clinical testing	Genome Diagnostics Laboratory, University Medical Center Utrecht	-	- -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jan 02, 2020

The p.I306V variant (also known as c.916A>G), located in coding exon 7 of the POT1 gene, results from an A to G substitution at nucleotide position 916. The isoleucine at codon 306 is replaced by valine, an amino acid with highly similar properties. This amino acid position is not well 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

Jan 05, 2023

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. 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. ClinVar contains an entry for this variant (Variation ID: 942376). This variant has not been reported in the literature in individuals affected with POT1-related conditions. This variant is present in population databases (no rsID available, gnomAD 0.002%). This sequence change replaces isoleucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 306 of the POT1 protein (p.Ile306Val). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.066
BayesDel_addAF	Benign	-0.37	T
BayesDel_noAF	Benign	-0.76
CADD	Benign	0.21
DANN	Benign	0.18
DEOGEN2	Benign	0.093	T;T
Eigen	Benign	-1.2
Eigen_PC	Benign	-1.2
FATHMM_MKL	Benign	0.026	N
LIST_S2	Benign	0.50	T;T
M_CAP	Benign	0.0049	T
MetaRNN	Benign	0.068	T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	0.57	N;.
PrimateAI	Benign	0.31	T
PROVEAN	Benign	-0.080	N;N
REVEL	Benign	0.012
Sift	Benign	0.80	T;T
Sift4G	Benign	0.42	T;T
Polyphen		0.0	B;.
Vest4		0.065
MutPred		0.13		Gain of phosphorylation at S309 (P = 0.1888);.;
MVP		0.18
MPC		0.070
ClinPred		0.023	T
GERP RS		-1.4
Varity_R		0.023
gMVP		0.19

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: rs1415345156; hg19: chr7-124491959;