7-124863556-T-G

Variant names:

• chr7-124863556-T-G
• rs146552802
• NM_015450.3:c.340A>C

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 4P and 2B. PM1 PM2 BP4_Moderate

The NM_015450.3(POT1):​c.340A>C​(p.Ile114Leu) 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. 16/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I114V) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: POT1 NM_015450.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -1.09
• Publications: 0 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: Uncertain_significance. The variant received 2 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 3 benign, 28 uncertain in NM_015450.3
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.078550786).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
POT1	NM_015450.3	c.340A>C	p.Ile114Leu	missense_variant	Exon 8 of 19	ENST00000357628.8	NP_056265.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
POT1	ENST00000357628.8	c.340A>C	p.Ile114Leu	missense_variant	Exon 8 of 19	2	NM_015450.3	ENSP00000350249.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Tumor predisposition syndrome 3 Uncertain:1

Jul 12, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces isoleucine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 114 of the POT1 protein (p.Ile114Leu). 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 (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. ClinVar contains an entry for this variant (Variation ID: 1460762). This variant has not been reported in the literature in individuals affected with POT1-related conditions. This variant is not present in population databases (gnomAD no frequency).

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.10
BayesDel_addAF	Benign	-0.23	T
BayesDel_noAF	Benign	-0.57
CADD	Benign	9.7
DANN	Benign	0.78
DEOGEN2	Benign	0.39	T
Eigen	Benign	-1.4
Eigen_PC	Benign	-1.4
FATHMM_MKL	Benign	0.14	N
LIST_S2	Benign	0.68	T
M_CAP	Benign	0.0097	T
MetaRNN	Benign	0.079	T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	0.46	N
PhyloP100		-1.1
PrimateAI	Benign	0.30	T
PROVEAN	Benign	-0.85	N
REVEL	Benign	0.031
Sift	Benign	0.096	T
Sift4G	Uncertain	0.025	D
Vest4		0.15
ClinPred		0.070	T
GERP RS		-4.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.29
gMVP		0.66
Mutation Taster		=93/7	polymorphism

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

Other links and lift over

dbSNP: rs146552802; hg19: chr7-124503610;