rs559554788

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 2P and 3B. PM2BP4_ModerateBP6

The NM_000057.4(BLM):​c.2161G>A​(p.Val721Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000285 in 1,612,270 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000029 ( 0 hom. )

Consequence

BLM
NM_000057.4 missense

Scores

3
16

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:1

Conservation

PhyloP100: 3.21
Variant links:
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 Likely_benign. Variant got -1 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.16814351).
BP6
Variant 15-90765382-G-A is Benign according to our data. Variant chr15-90765382-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 454096.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=1}.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
BLMNM_000057.4 linkuse as main transcriptc.2161G>A p.Val721Ile missense_variant 9/22 ENST00000355112.8 NP_000048.1

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
BLMENST00000355112.8 linkuse as main transcriptc.2161G>A p.Val721Ile missense_variant 9/221 NM_000057.4 ENSP00000347232 P2

Frequencies

GnomAD3 genomes
AF:
0.0000263
AC:
4
AN:
152102
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000414
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000438
AC:
11
AN:
251338
Hom.:
0
AF XY:
0.0000663
AC XY:
9
AN XY:
135836
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.000359
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000288
AC:
42
AN:
1460168
Hom.:
0
Cov.:
31
AF XY:
0.0000413
AC XY:
30
AN XY:
726580
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.0000252
Gnomad4 SAS exome
AF:
0.000278
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000135
Gnomad4 OTH exome
AF:
0.0000332
GnomAD4 genome
AF:
0.0000263
AC:
4
AN:
152102
Hom.:
0
Cov.:
32
AF XY:
0.0000404
AC XY:
3
AN XY:
74284
show subpopulations
Gnomad4 AFR
AF:
0.0000241
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.000414
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000147
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000492
Hom.:
0
Bravo
AF:
0.00000378
ExAC
AF:
0.0000165
AC:
2

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:2Benign:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Bloom syndrome Uncertain:2
Uncertain significance, no assertion criteria providedclinical testingNatera, Inc.Sep 16, 2020- -
Uncertain significance, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpJan 04, 2024This sequence change replaces valine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 721 of the BLM protein (p.Val721Ile). This variant is present in population databases (rs559554788, gnomAD 0.04%). 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: 454096). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt BLM protein function with a negative predictive value of 80%. 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. -
Hereditary cancer-predisposing syndrome Benign:1
Likely benign, criteria provided, single submitterclinical testingAmbry GeneticsMar 14, 2024This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.070
BayesDel_addAF
Benign
-0.49
T
BayesDel_noAF
Benign
-0.64
CADD
Benign
16
DANN
Uncertain
0.98
DEOGEN2
Benign
0.066
T;.
Eigen
Benign
-0.27
Eigen_PC
Benign
-0.096
FATHMM_MKL
Uncertain
0.94
D
LIST_S2
Uncertain
0.90
D;D
M_CAP
Benign
0.0062
T
MetaRNN
Benign
0.17
T;T
MetaSVM
Benign
-1.0
T
MutationAssessor
Benign
0.34
N;.
MutationTaster
Benign
0.99
D;D
PrimateAI
Benign
0.45
T
PROVEAN
Benign
-0.28
N;N
REVEL
Benign
0.026
Sift
Benign
0.20
T;T
Sift4G
Benign
0.36
T;T
Polyphen
0.14
B;.
Vest4
0.074
MVP
0.63
MPC
0.081
ClinPred
0.081
T
GERP RS
2.9
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.043
gMVP
0.45

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs559554788; hg19: chr15-91308612; COSMIC: COSV61925866; COSMIC: COSV61925866; API