rs587779891
Variant summary
Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4_Moderate
The NM_000057.4(BLM):c.4112C>T(p.Thr1371Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000155 in 1,614,048 control chromosomes in the GnomAD database, with no homozygous occurrence. 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 Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. T1371T) has been classified as Likely benign.
Frequency
Consequence
NM_000057.4 missense
Scores
Clinical Significance
Conservation
Publications
- Bloom syndromeInheritance: AR Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: Myriad Women’s Health, Labcorp Genetics (formerly Invitae), G2P, Laboratory for Molecular Medicine, Orphanet, Genomics England PanelApp, ClinGen
- osteosarcomaInheritance: AR Classification: MODERATE Submitted by: Genomics England PanelApp
- breast cancerInheritance: AD Classification: NO_KNOWN Submitted by: Ambry Genetics
- hereditary nonpolyposis colon cancerInheritance: AD Classification: NO_KNOWN Submitted by: Ambry Genetics
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ACMG classification
Our verdict: Likely_benign. The variant received -2 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000263 AC: 4AN: 152176Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000239 AC: 6AN: 251482 AF XY: 0.0000221 show subpopulations
GnomAD4 exome AF: 0.0000144 AC: 21AN: 1461872Hom.: 0 Cov.: 31 AF XY: 0.0000124 AC XY: 9AN XY: 727234 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000263 AC: 4AN: 152176Hom.: 0 Cov.: 32 AF XY: 0.0000404 AC XY: 3AN XY: 74340 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Bloom syndrome Uncertain:3
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This sequence change replaces threonine, which is neutral and polar, with methionine, which is neutral and non-polar, at codon 1371 of the BLM protein (p.Thr1371Met). This variant is present in population databases (rs587779891, gnomAD 0.005%). This variant has not been reported in the literature in individuals affected with BLM-related conditions. ClinVar contains an entry for this variant (Variation ID: 127510). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. 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. -
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not provided Uncertain:2
Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -
The BLM c.4112C>T (p.Thr1371Met) variant has been briefly reported in the published literature in an individual affected with neuroendocrine/adrenal cancer or colon cancer (PMID: 35988656 (2022)). The frequency of this variant in the general population, 0.000044 (5/113764 chromosomes (Genome Aggregation Database, http://gnomad.broadinstitute.org)), is uninformative in the assessment of its pathogenicity. Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded predictions that this variant is benign. Based on the available information, we are unable to determine the clinical significance of this variant. -
Hereditary cancer-predisposing syndrome Uncertain:2
The p.T1371M variant (also known as c.4112C>T), located in coding exon 21 of the BLM gene, results from a C to T substitution at nucleotide position 4112. The threonine at codon 1371 is replaced by methionine, an amino acid with similar properties. 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. -
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not specified Uncertain:1
Variant summary: BLM c.4112C>T (p.Thr1371Met) results in a non-conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 2.4e-05 in 251482 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.4112C>T in individuals affected with Bloom Syndrome and no experimental evidence demonstrating its impact on protein function have been reported. Five ClinVar submitters (evaluation after 2014) cite the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at