rs746416077

Positions:

• chr7-124841164-T-A
• chr7-124841164-T-C
• chr7-124841164-T-G

Variant summary

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

The NM_015450.3(POT1):​c.1178A>T​(p.His393Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,459,488 control chromosomes in the GnomAD database, with no homozygous occurrence. 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 (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: POT1 NM_015450.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 1.05

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=0.1402913).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
POT1	NM_015450.3	c.1178A>T	p.His393Leu	missense_variant	14/19	ENST00000357628.8	NP_056265.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
POT1	ENST00000357628.8	c.1178A>T	p.His393Leu	missense_variant	14/19	2	NM_015450.3	ENSP00000350249	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000801 AC: 2 AN: 249608 Hom.: 0 AF XY: 0.0000148 AC XY: 2 AN XY: 134856

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000582

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: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1459488 Hom.: 0 Cov.: 31 AF XY: 0.00000276 AC XY: 2 AN XY: 725934

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000448

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

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

Jul 21, 2022

The p.H393L variant (also known as c.1178A>T), located in coding exon 10 of the POT1 gene, results from an A to T substitution at nucleotide position 1178. The histidine at codon 393 is replaced by leucine, an amino acid with 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. -

Tumor predisposition syndrome 3 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Apr 25, 2023

This sequence change replaces histidine, which is basic and polar, with leucine, which is neutral and non-polar, at codon 393 of the POT1 protein (p.His393Leu). 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: 1741223). 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 0.006%). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.081
BayesDel_addAF	Benign	-0.25	T
BayesDel_noAF	Benign	-0.42
CADD	Benign	18
DANN	Benign	0.87
DEOGEN2	Benign	0.29	T;T;T
Eigen	Benign	-0.66
Eigen_PC	Benign	-0.57
FATHMM_MKL	Uncertain	0.84	D
LIST_S2	Benign	0.73	T;T;.
M_CAP	Benign	0.013	T
MetaRNN	Benign	0.14	T;T;T
MetaSVM	Benign	-0.99	T
MutationAssessor	Uncertain	2.4	M;.;.
MutationTaster	Benign	0.99	N;N
PrimateAI	Benign	0.23	T
PROVEAN	Uncertain	-2.9	D;D;.
REVEL	Benign	0.091
Sift	Benign	0.062	T;T;.
Sift4G	Benign	0.064	T;T;T
Polyphen		0.015	B;.;.
Vest4		0.34
MutPred		0.44		Gain of sheet (P = 0.1208);.;.;
MVP		0.40
MPC		0.12
ClinPred		0.55	D
GERP RS		1.9
Varity_R		0.33
gMVP		0.48

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs746416077; hg19: chr7-124481218;