15-90769137-G-A
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Variant summary
Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2PP3
The NM_000057.4(BLM):c.2312G>A(p.Cys771Tyr) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic 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. C771F) has been classified as Uncertain significance.
Frequency
Genomes: not found (cov: 32)
Consequence
BLM
NM_000057.4 missense
NM_000057.4 missense
Scores
5
11
3
Clinical Significance
Conservation
PhyloP100: 6.40
Genes affected
BLM (HGNC:1058): (BLM RecQ like helicase) The Bloom syndrome is an autosomal recessive disorder characterized by growth deficiency, microcephaly and immunodeficiency among others. It is caused by homozygous or compound heterozygous mutation in the gene encoding DNA helicase RecQ protein on chromosome 15q26. This Bloom-associated helicase unwinds a variety of DNA substrates including Holliday junction, and is involved in several pathways contributing to the maintenance of genome stability. Identification of pathogenic Bloom variants is required for heterozygote testing in at-risk families. [provided by RefSeq, May 2020]
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ACMG classification
Classification made for transcript
Verdict is Uncertain_significance. Variant got 3 ACMG points.
PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.828
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | MANE | UniProt |
---|---|---|---|---|---|---|---|
BLM | NM_000057.4 | c.2312G>A | p.Cys771Tyr | missense_variant | 11/22 | ENST00000355112.8 |
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | TSL | MANE | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|
BLM | ENST00000355112.8 | c.2312G>A | p.Cys771Tyr | missense_variant | 11/22 | 1 | NM_000057.4 | P2 |
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD3 genomes
Cov.:
32
GnomAD4 exome Cov.: 31
GnomAD4 exome
Cov.:
31
GnomAD4 genome Cov.: 32
GnomAD4 genome
Cov.:
32
ClinVar
Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link
Submissions by phenotype
Bloom syndrome Uncertain:1
Uncertain significance, criteria provided, single submitter | clinical testing | Invitae | Aug 31, 2022 | Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). 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. ClinVar contains an entry for this variant (Variation ID: 524789). This variant has not been reported in the literature in individuals affected with BLM-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces cysteine, which is neutral and slightly polar, with tyrosine, which is neutral and polar, at codon 771 of the BLM protein (p.Cys771Tyr). - |
Hereditary cancer-predisposing syndrome Uncertain:1
Uncertain significance, criteria provided, single submitter | clinical testing | Ambry Genetics | Jan 02, 2024 | The p.C771Y variant (also known as c.2312G>A), located in coding exon 10 of the BLM gene, results from a G to A substitution at nucleotide position 2312. The cysteine at codon 771 is replaced by tyrosine, an amino acid with highly dissimilar properties. This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. - |
Computational scores
Source:
Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
BayesDel_addAF
Pathogenic
D
BayesDel_noAF
Uncertain
CADD
Pathogenic
DANN
Uncertain
DEOGEN2
Benign
T;.
Eigen
Uncertain
Eigen_PC
Uncertain
FATHMM_MKL
Pathogenic
D
LIST_S2
Uncertain
D;D
M_CAP
Uncertain
D
MetaRNN
Pathogenic
D;D
MetaSVM
Uncertain
T
MutationAssessor
Benign
L;.
MutationTaster
Benign
D;D
PrimateAI
Uncertain
T
PROVEAN
Pathogenic
D;D
REVEL
Uncertain
Sift
Uncertain
D;D
Sift4G
Uncertain
D;D
Polyphen
D;.
Vest4
MutPred
Loss of sheet (P = 0.0011);Loss of sheet (P = 0.0011);
MVP
MPC
ClinPred
D
GERP RS
Varity_R
gMVP
Splicing
Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
Details are displayed if max score is > 0.2
Find out detailed SpliceAI scores and Pangolin per-transcript scores at