NM_015450.3:c.747A>C

Variant names:

• chr7-124853094-T-G
• rs35361862
• NM_015450.3:c.747A>C

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_015450.3(POT1):​c.747A>C​(p.Gln249His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000687 in 1,455,616 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 (★). Synonymous variant affecting the same amino acid position (i.e. Q249Q) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: POT1 NM_015450.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -2.25
• 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 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.1387702).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
POT1	NM_015450.3	c.747A>C	p.Gln249His	missense_variant	Exon 10 of 19	ENST00000357628.8	NP_056265.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
POT1	ENST00000357628.8	c.747A>C	p.Gln249His	missense_variant	Exon 10 of 19	2	NM_015450.3	ENSP00000350249.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.87e-7 AC: 1 AN: 1455616 Hom.: 0 Cov.: 29 AF XY: 0.00000138 AC XY: 1 AN XY: 724430

African (AFR) AF: 0.00 AC: 0 AN: 33312

American (AMR) AF: 0.00 AC: 0 AN: 44654

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26074

East Asian (EAS) AF: 0.00 AC: 0 AN: 39612

South Asian (SAS) AF: 0.00 AC: 0 AN: 85948

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53404

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5760

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1106658

Other (OTH) AF: 0.0000166 AC: 1 AN: 60194

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Tumor predisposition syndrome 3 Uncertain:1

Oct 13, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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 histidine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. This variant has not been reported in the literature in individuals affected with POT1-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change replaces glutamine with histidine at codon 249 of the POT1 protein (p.Gln249His). The glutamine residue is moderately conserved and there is a small physicochemical difference between glutamine and histidine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.28
BayesDel_addAF	Benign	-0.26	T
BayesDel_noAF	Benign	-0.60
CADD	Benign	0.57
DANN	Benign	0.84
DEOGEN2	Uncertain	0.49	T;T
Eigen	Benign	-1.1
Eigen_PC	Benign	-1.1
FATHMM_MKL	Benign	0.035	N
LIST_S2	Benign	0.77	T;T
M_CAP	Benign	0.0040	T
MetaRNN	Benign	0.14	T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	1.6	L;.
PhyloP100		-2.3
PrimateAI	Benign	0.46	T
PROVEAN	Benign	-0.85	N;N
REVEL	Benign	0.028
Sift	Benign	0.23	T;T
Sift4G	Benign	0.34	T;T
Polyphen		0.0060	B;.
Vest4		0.23
MutPred		0.21		Gain of catalytic residue at K247 (P = 0.0561);.;
MVP		0.32
MPC		0.83
ClinPred		0.085	T
GERP RS		-5.4
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.14
gMVP		0.55
Mutation Taster		=80/20	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.060		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: rs35361862; hg19: chr7-124493148;