chr7-124853088-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
Consequence
NM_015450.3 missense
Scores
Clinical Significance
Conservation
Publications
- pulmonary fibrosis and/or bone marrow failure syndrome, telomere-related, 8Inheritance: AD Classification: STRONG, LIMITED Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
- tumor predisposition syndrome 3Inheritance: AD Classification: MODERATE Submitted by: Ambry Genetics
- glioma susceptibility 9Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
- thyroid gland carcinomaInheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
- cerebroretinal microangiopathy with calcifications and cysts 3Inheritance: AR Classification: LIMITED Submitted by: G2P, Ambry Genetics
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ACMG classification
Our verdict: Likely_benign. The variant received -2 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| POT1 | NM_015450.3 | c.753G>A | p.Met251Ile | missense_variant | Exon 10 of 19 | ENST00000357628.8 | NP_056265.2 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000658 AC: 1AN: 152068Hom.: 0 Cov.: 33 show subpopulations
GnomAD4 exome AF: 6.87e-7 AC: 1AN: 1456110Hom.: 0 Cov.: 29 AF XY: 0.00000138 AC XY: 1AN XY: 724640 show subpopulations ⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
Age Distribution
GnomAD4 genome AF: 0.00000658 AC: 1AN: 152068Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0AN XY: 74294 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Hereditary cancer-predisposing syndrome Uncertain:1
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
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:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at