7-124853088-C-T

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2BP4_Strong

The NM_015450.3(POT1):​c.753G>A​(p.Met251Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,608,178 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Likely benign in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M251V) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 6.9e-7 ( 0 hom. )

Consequence

POT1
NM_015450.3 missense

Scores

19

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 0.00700

Publications

6 publications found
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 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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -2 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.06328106).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
POT1NM_015450.3 linkc.753G>A p.Met251Ile missense_variant Exon 10 of 19 ENST00000357628.8 NP_056265.2 Q9NUX5-1A0A024R739

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
POT1ENST00000357628.8 linkc.753G>A p.Met251Ile missense_variant Exon 10 of 19 2 NM_015450.3 ENSP00000350249.3 Q9NUX5-1

Frequencies

GnomAD3 genomes
AF:
0.00000658
AC:
1
AN:
152068
Hom.:
0
Cov.:
33
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:
6.87e-7
AC:
1
AN:
1456110
Hom.:
0
Cov.:
29
AF XY:
0.00000138
AC XY:
1
AN XY:
724640
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
33326
American (AMR)
AF:
0.00
AC:
0
AN:
44648
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26074
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39618
South Asian (SAS)
AF:
0.00
AC:
0
AN:
85964
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53402
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5762
European-Non Finnish (NFE)
AF:
9.03e-7
AC:
1
AN:
1107112
Other (OTH)
AF:
0.00
AC:
0
AN:
60204
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.325
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.00000658
AC:
1
AN:
152068
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
74294
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41430
American (AMR)
AF:
0.00
AC:
0
AN:
15264
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5192
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10606
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
67966
Other (OTH)
AF:
0.00
AC:
0
AN:
2084
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.575
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.0000189

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1
Jun 27, 2023
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.M251I variant (also known as c.753G>A), located in coding exon 6 of the POT1 gene, results from a G to A substitution at nucleotide position 753. The methionine at codon 251 is replaced by isoleucine, an amino acid with highly similar properties. This variant was described as a germline finding in 1/3323 consecutive patients who had clinical testing for variants associated with hematologic malignancies (Lim TL et al. Leukemia, 2022 Jan;36:283-287). This amino acid position is poorly 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
Nov 26, 2019
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant has not been reported in the literature in individuals with POT1-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change replaces methionine with isoleucine at codon 251 of the POT1 protein (p.Met251Ile). The methionine residue is weakly conserved and there is a small physicochemical difference between methionine and isoleucine. 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. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The isoleucine amino acid residue is found in multiple mammalian species, suggesting that this missense change does not adversely affect protein function. These predictions have not been confirmed by published functional studies and their clinical significance is uncertain. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.11
BayesDel_addAF
Benign
-0.34
T
BayesDel_noAF
Benign
-0.73
CADD
Benign
11
DANN
Benign
0.67
DEOGEN2
Benign
0.30
T;T
Eigen
Benign
-1.2
Eigen_PC
Benign
-1.2
FATHMM_MKL
Benign
0.050
N
LIST_S2
Benign
0.57
T;T
M_CAP
Benign
0.0062
T
MetaRNN
Benign
0.063
T;T
MetaSVM
Benign
-1.0
T
MutationAssessor
Benign
-0.69
N;.
PhyloP100
0.0070
PrimateAI
Benign
0.25
T
PROVEAN
Benign
0.29
N;N
REVEL
Benign
0.018
Sift
Benign
0.40
T;T
Sift4G
Benign
0.48
T;T
Polyphen
0.0
B;.
Vest4
0.090
MutPred
0.28
Loss of ubiquitination at K247 (P = 0.0496);.;
MVP
0.18
MPC
0.97
ClinPred
0.024
T
GERP RS
-2.0
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.17
gMVP
0.27
Mutation Taster
=83/17
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.16
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs1172142052; hg19: chr7-124493142; API