chr7-124846962-C-T

Position:

• chr7-124846962-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP3

The NM_015450.3(POT1):​c.986G>A​(p.Cys329Tyr) variant causes a missense change. The variant allele was found at a frequency of 0.00000275 in 1,452,920 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000028 (0 hom.)
• Consequence: POT1 NM_015450.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 4.19

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 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.832

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
POT1	NM_015450.3	c.986G>A	p.Cys329Tyr	missense_variant	12/19	ENST00000357628.8	NP_056265.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
POT1	ENST00000357628.8	c.986G>A	p.Cys329Tyr	missense_variant	12/19	2	NM_015450.3	ENSP00000350249.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000275 AC: 4 AN: 1452920 Hom.: 0 Cov.: 29 AF XY: 0.00000553 AC XY: 4 AN XY: 723432

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: 0.00000362

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Nov 15, 2022

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

May 15, 2023

The p.C329Y variant (also known as c.986G>A), located in coding exon 8 of the POT1 gene, results from a G to A substitution at nucleotide position 986. The cysteine at codon 329 is replaced by tyrosine, an amino acid with highly dissimilar properties. This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. 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 19, 2024

This sequence change replaces cysteine, which is neutral and slightly polar, with tyrosine, which is neutral and polar, at codon 329 of the POT1 protein (p.Cys329Tyr). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. 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: 475116). 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	Uncertain	0.48
BayesDel_addAF	Pathogenic	0.25	D
BayesDel_noAF	Uncertain	0.12
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.64	D;T
Eigen	Uncertain	0.62
Eigen_PC	Uncertain	0.61
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.92	D;D
M_CAP	Benign	0.032	D
MetaRNN	Pathogenic	0.83	D;D
MetaSVM	Benign	-0.71	T
MutationAssessor	Uncertain	2.7	M;.
PrimateAI	Uncertain	0.77	T
PROVEAN	Uncertain	-3.3	D;D
REVEL	Uncertain	0.43
Sift	Uncertain	0.0030	D;D
Sift4G	Uncertain	0.015	D;D
Polyphen		1.0	D;.
Vest4		0.79
MutPred		0.70		Gain of sheet (P = 0.0827);.;
MVP		0.62
MPC		0.54
ClinPred		0.96	D
GERP RS		5.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.54
gMVP		0.60

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.090		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: rs1472832603; hg19: chr7-124487016;