7-124840994-C-T

Variant names:

• chr7-124840994-C-T
• rs797045169
• NM_015450.3:c.1348G>A

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 2P and 3B. PM2 BP4_Moderate BP6

The NM_015450.3(POT1):​c.1348G>A​(p.Glu450Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. E450G) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: POT1 NM_015450.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:1
• Conservation: PhyloP100: 0.667
• Publications: 6 publications found

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 Gene-Disease associations (from GenCC):

• pulmonary fibrosis and/or bone marrow failure syndrome, telomere-related, 8

  Inheritance: AD Classification: STRONG, LIMITED Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
• tumor predisposition syndrome 3

  Inheritance: AD Classification: MODERATE Submitted by: Ambry Genetics
• glioma susceptibility 9

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
• thyroid gland carcinoma

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
• cerebroretinal microangiopathy with calcifications and cysts 3

  Inheritance: AR Classification: LIMITED Submitted by: G2P, Ambry Genetics

ACMG classification

Our verdict: Likely_benign. The variant received -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.1546076).
• BP6: Variant 7-124840994-C-T is Benign according to our data. Variant chr7-124840994-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 1770526.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
POT1	NM_015450.3	c.1348G>A	p.Glu450Lys	missense_variant	Exon 14 of 19	ENST00000357628.8	NP_056265.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
POT1	ENST00000357628.8	c.1348G>A	p.Glu450Lys	missense_variant	Exon 14 of 19	2	NM_015450.3	ENSP00000350249.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Tumor predisposition syndrome 3 Uncertain:1

Nov 05, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glutamic acid, which is acidic and polar, with lysine, which is basic and polar, at codon 450 of the POT1 protein (p.Glu450Lys). 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: 1770526). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) 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. -

Hereditary cancer-predisposing syndrome Benign:1

Dec 02, 2024

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.092
BayesDel_addAF	Benign	-0.18	T
BayesDel_noAF	Benign	-0.49
CADD	Benign	20
DANN	Uncertain	0.99
DEOGEN2	Benign	0.19	T;T;T
Eigen	Benign	-0.22
Eigen_PC	Benign	-0.088
FATHMM_MKL	Uncertain	0.78	D
LIST_S2	Uncertain	0.92	D;D;.
M_CAP	Benign	0.0076	T
MetaRNN	Benign	0.15	T;T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	2.0	M;.;.
PhyloP100		0.67
PrimateAI	Benign	0.32	T
PROVEAN	Benign	-1.0	N;N;.
REVEL	Benign	0.012
Sift	Benign	0.12	T;T;.
Sift4G	Benign	0.53	T;T;D
Polyphen		0.22	B;.;.
Vest4		0.23
MutPred		0.46		Gain of methylation at E450 (P = 0.0092);.;.;
MVP		0.39
MPC		0.10
ClinPred		0.31	T
GERP RS		3.5
Varity_R		0.12
gMVP		0.53
Mutation Taster		=89/11	polymorphism

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

Other links and lift over

dbSNP: rs797045169; hg19: chr7-124481048; COSMIC: COSV100714126;