rs777492549

Variant names:

Your query was ambiguous. Multiple possible variants found:

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 0P and 0B.

The NM_000057.4(BLM):c.3505G>A(p.Ala1169Thr) variant causes a missense change. The variant allele was found at a frequency of 0.000013 in 1,614,002 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A1169V) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000014 ( 0 hom. )

Consequence

BLM
NM_000057.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5B:1

Conservation

PhyloP100: 5.79

Publications

3 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:

ENSG00000300894 (HGNC:):

ENSG00000300894 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
BLM	NM_000057.4 link	c.3505G>A	p.Ala1169Thr	missense_variant	Exon 18 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.3505G>A	p.Ala1169Thr	missense_variant	Exon 18 of 22	1	NM_000057.4	ENSP00000347232.3		P54132

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152152

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000676

AC:

AN:

251414

AF XY:

0.0000809

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000434

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000176

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000137

AC:

AN:

1461850

Hom.:

Cov.:

AF XY:

0.0000165

AC XY:

AN XY:

727222

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33478

American (AMR)

AF:

0.000313

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26132

East Asian (EAS)

AF:

0.00

AC:

AN:

39684

South Asian (SAS)

AF:

0.00

AC:

AN:

86256

European-Finnish (FIN)

AF:

0.0000187

AC:

AN:

53420

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00000450

AC:

AN:

1111994

Other (OTH)

AF:

0.00

AC:

AN:

60394

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.458

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:

0.00000657

AC:

AN:

152152

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74324

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41436

American (AMR)

AF:

0.0000655

AC:

AN:

15272

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5196

South Asian (SAS)

AF:

0.00

AC:

AN:

4826

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10598

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68034

Other (OTH)

AF:

0.00

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.425

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.0000282

Hom.:

Bravo

AF:

0.0000227

ExAC

AF:

0.0000576

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:5Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Bloom syndrome

Uncertain:3

Oct 29, 2018

Natera, Inc.

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Sep 09, 2021

Fulgent Genetics, Fulgent Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jan 16, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 1169 of the BLM protein (p.Ala1169Thr). This variant is present in population databases (rs777492549, 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: 524814). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) 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. -

not provided

Uncertain:1

Dec 27, 2023

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The BLM c.3505G>A (p.Ala1169Thr) variant has been reported in the published literature in identified in a reportedly healthy individual (PMID: 29641532 (2018)). The frequency of this variant in the general population, 0.00043 (15/34592 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:1

Mar 16, 2023

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.A1169T variant (also known as c.3505G>A), located in coding exon 17 of the BLM gene, results from a G to A substitution at nucleotide position 3505. The alanine at codon 1169 is replaced by threonine, an amino acid with similar properties. This alteration was identified in 1/1358 non-cancer control individuals and was not observed in 57 cases, in a study looking at cancer predisposition mutations in patients with cutaneous melanoma and a history of at least two additional non-cutaneous melanoma primary cancers (Pritchard AL et al. PLoS One, 2018 Apr;13:e0194098).This amino acid position is 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. -

Ovarian cancer

Benign:1

Jan 01, 2022

Laboratory of Molecular Epidemiology of Birth Defects, West China Second University Hospital, Sichuan University

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.27

BayesDel_addAF

Benign

-0.29

BayesDel_noAF

Benign

-0.33

CADD

Benign

(source)

DANN

Pathogenic

1.0

DEOGEN2

Benign

0.36

Eigen

Uncertain

0.37

Eigen_PC

Uncertain

0.42

FATHMM_MKL

Uncertain

0.95

LIST_S2

Uncertain

0.89

M_CAP

Benign

0.036

MetaRNN

Uncertain

0.61

MetaSVM

Benign

-0.90

MutationAssessor

Uncertain

2.2

PhyloP100

5.8

PrimateAI

Uncertain

0.58

PROVEAN

Uncertain

-3.1

REVEL

Benign

0.24

Sift

Uncertain

0.0040

Sift4G

Uncertain

0.016

Polyphen

0.78

Vest4

0.66

MutPred

0.59

Gain of helix (P = 0.0117);

MVP

0.87

MPC

0.42

ClinPred

0.28

GERP RS

5.7

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.70

gMVP

0.67

Mutation Taster

=72/28

polymorphism

(source)

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

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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