rs28385012

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BP4_Strong

The NM_000057.4(BLM):c.1772G>A(p.Arg591Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000111 in 1,531,960 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 variant affecting the same amino acid position, but resulting in a different missense (i.e. R591G) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000010 ( 0 hom. )

Consequence

BLM
NM_000057.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 0.827

Publications

5 publications found

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]

BLM Gene-Disease associations (from GenCC):

Bloom syndrome
Inheritance: 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
osteosarcoma
Inheritance: AR Classification: MODERATE Submitted by: Genomics England PanelApp
breast cancer
Inheritance: AD Classification: NO_KNOWN Submitted by: Ambry Genetics
hereditary nonpolyposis colon cancer
Inheritance: AD Classification: NO_KNOWN Submitted by: Ambry Genetics

BLM links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -4 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.047082186).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
BLM	NM_000057.4 link	c.1772G>A	p.Arg591Gln	missense_variant	Exon 7 of 22	ENST00000355112.8	NP_000048.1	P54132

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
BLM	ENST00000355112.8 link	c.1772G>A	p.Arg591Gln	missense_variant	Exon 7 of 22	1	NM_000057.4	ENSP00000347232.3		P54132

Frequencies

GnomAD3 genomes

AF:

0.0000197

AC:

AN:

152082

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000242

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000218

AC:

AN:

183460

AF XY:

0.0000310

show subpopulations

Gnomad AFR exome

AF:

0.0000649

Gnomad AMR exome

AF:

0.0000465

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000126

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000101

AC:

AN:

1379760

Hom.:

Cov.:

AF XY:

0.0000103

AC XY:

AN XY:

678732

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

30474

American (AMR)

AF:

0.0000664

AC:

AN:

30098

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

20646

East Asian (EAS)

AF:

0.0000767

AC:

AN:

39128

South Asian (SAS)

AF:

0.00

AC:

AN:

70404

European-Finnish (FIN)

AF:

0.00

AC:

AN:

50190

Middle Eastern (MID)

AF:

0.000186

AC:

AN:

5368

European-Non Finnish (NFE)

AF:

0.00000650

AC:

AN:

1076632

Other (OTH)

AF:

0.0000176

AC:

AN:

56820

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.454

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.0000197

AC:

AN:

152200

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74420

show subpopulations

African (AFR)

AF:

0.0000241

AC:

AN:

41520

American (AMR)

AF:

0.00

AC:

AN:

15290

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5182

South Asian (SAS)

AF:

0.00

AC:

AN:

4820

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10588

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.0000294

AC:

AN:

68010

Other (OTH)

AF:

0.00

AC:

AN:

2114

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.492

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.00000756

ExAC

AF:

0.00000826

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Bloom syndrome

Uncertain:3

Jun 14, 2024

Fulgent Genetics, Fulgent Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jan 01, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 591 of the BLM protein (p.Arg591Gln). This variant is present in population databases (rs28385012, gnomAD 0.01%). 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: 583411). 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. -

Oct 23, 2018

Natera, Inc.

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Hereditary cancer-predisposing syndrome

Uncertain:1

Jul 26, 2023

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.R591Q variant (also known as c.1772G>A), located in coding exon 6 of the BLM gene, results from a G to A substitution at nucleotide position 1772. The arginine at codon 591 is replaced by glutamine, an amino acid with highly similar properties. This amino acid position is not well 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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.075

BayesDel_addAF

Benign

-0.52

BayesDel_noAF

Benign

-0.75

CADD

Benign

(source)

DANN

Benign

0.89

DEOGEN2

Benign

0.058

T;.

Eigen

Benign

-0.88

Eigen_PC

Benign

-0.76

FATHMM_MKL

Benign

0.21

LIST_S2

Benign

0.80

T;T

M_CAP

Benign

0.0052

MetaRNN

Benign

0.047

T;T

MetaSVM

Benign

-1.0

MutationAssessor

Benign

1.4

L;.

PhyloP100

0.83

PrimateAI

Benign

0.18

PROVEAN

Benign

0.27

N;N

REVEL

Benign

0.016

Sift

Benign

0.36

T;T

Sift4G

Benign

0.63

T;T

Polyphen

0.0050

B;.

Vest4

0.048

MVP

0.70

MPC

0.10

ClinPred

0.024

GERP RS

2.6

Varity_R

0.016

gMVP

0.44

Mutation Taster

=94/6

polymorphism

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.010

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over