Genetic Variant POT1:p.Ile49MetfsTer7 (chr7-124871018-CA-C) – ACMG Classification: Pathogenic (18 pts)

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_015450.3(POT1):c.147delT(p.Ile49MetfsTer7) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000311 in 1,607,744 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000027 ( 0 hom. )

Consequence

POT1
NM_015450.3 frameshift

Scores

Not classified

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:5

Conservation

PhyloP100: 1.51

Variant links:

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 links:

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ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 ACMG points.

PVS1

Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 7-124871018-CA-C is Pathogenic according to our data. Variant chr7-124871018-CA-C is described in ClinVar as [Pathogenic]. Clinvar id is 420174.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
POT1	NM_015450.3 link	c.147delT	p.Ile49MetfsTer7	frameshift_variant	Exon 7 of 19	ENST00000357628.8	NP_056265.2	Q9NUX5-1A0A024R739

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
POT1	ENST00000357628.8 link	c.147delT	p.Ile49MetfsTer7	frameshift_variant	Exon 7 of 19	2	NM_015450.3	ENSP00000350249.3		Q9NUX5-1

Frequencies

GnomAD3 genomes

AF:

0.00000658

AC:

AN:

152076

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

0.00000275

AC:

AN:

1455668

Hom.:

Cov.:

AF XY:

0.00000276

AC XY:

AN XY:

724208

show subpopulations

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:

0.00000361

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000658

AC:

AN:

152076

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74268

show subpopulations

Gnomad4 AFR

AF:

0.0000241

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:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000378

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Hereditary cancer-predisposing syndrome

Pathogenic:2

Jul 17, 2023

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as Pathogenic. Following criteria are met: 0102 - Loss of function is a known mechanism of disease in this gene and is associated with hereditary neoplastic syndrome (MONDO#0015356), POT1-related. (I) 0107 - This gene is associated with autosomal dominant disease. (I) 0112 - The condition associated with this gene has incomplete penetrance (PMIDs: 25482530, 29693246, 33216348). (I) 0201 - Variant is predicted to cause nonsense-mediated decay (NMD) and loss of protein (premature termination codon is located at least 54 nucleotides upstream of the final exon-exon junction). (SP) 0251 - This variant is heterozygous. (I) 0302 - Variant is present in gnomAD <0.001 for a dominant condition (v3: 1 heterozygote, 0 homozygotes). (SP) 0701 - Other NMD-predicted variants comparable to the one identified in this case have very strong previous evidence for pathogenicity (DECIPHER; PMIDs: 25482530, 27528712, 34769003). (SP) 0802 - This variant has moderate previous evidence of pathogenicity in unrelated individuals. It has been identified as a germline variant in an individual with a history of multiple primary tumours (PMID: 35456397), an individual with glioma (PMID: 25877891); and classified as likely pathogenic/pathogenic by diagnostic laboratories in ClinVar. (SP) 1007 - No published functional evidence has been identified for this variant. (I) 1208 - Inheritance information for this variant is not currently available in this individual. (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -

Jan 04, 2023

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.147delT pathogenic mutation, located in coding exon 3 of the POT1 gene, results from a deletion of one nucleotide at nucleotide position 147, causing a translational frameshift with a predicted alternate stop codon (p.I49Mfs*7). This alteration has been reported in an individual diagnosed with glioma (Jones S et al. Sci Transl Med, 2015 Apr;7:283ra53). In addition to the clinical data presented in the literature, this alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. As such, this alteration is interpreted as a disease-causing mutation. -

Long telomere syndrome

Pathogenic:1

Aug 01, 2022

The Telomere Center at Johns Hopkins, Johns Hopkins University School of Medicine

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

not provided

Pathogenic:1

Jul 10, 2023

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Frameshift variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss-of-function is a known mechanism of disease; Not observed in large population cohorts (gnomAD); Observed in an individual with glioma and in another individual with multiple cancers including lymphoma, melanoma, and papillary thyroid cancer (Jones et al., 2015; Jajosky et al., 2022); This variant is associated with the following publications: (PMID: 35456397, 25877891) -

Tumor predisposition syndrome 3

Pathogenic:1

Jan 30, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Ile49Metfs*7) in the POT1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in POT1 are known to be pathogenic (PMID: 32155570). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with glioma (PMID: 25877891). ClinVar contains an entry for this variant (Variation ID: 420174). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over