rs184657475

Variant names:

Your query was ambiguous. Multiple possible variants found:

Variant summary

Our verdict is Benign. The variant received -9 ACMG points: 0P and 9B. BP4_StrongBP6BS1

The NM_000057.4(BLM):c.1044G>A(p.Met348Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000824 in 1,613,918 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 Conflicting classifications of pathogenicity (no stars). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Uncertain significance in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M348T) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000079 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000083 ( 0 hom. )

Consequence

BLM
NM_000057.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3B:4

Conservation

PhyloP100: 0.169

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: Benign. The variant received -9 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.0044721067).

BP6

Variant 15-90754895-G-A is Benign according to our data. Variant chr15-90754895-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 413284.

BS1

Variant frequency is greater than expected in population eas. GnomAd4 allele frequency = 0.0000788 (12/152240) while in subpopulation EAS AF = 0.00231 (12/5184). AF 95% confidence interval is 0.00134. There are 0 homozygotes in GnomAd4. There are 8 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
BLM	NM_000057.4 link	c.1044G>A	p.Met348Ile	missense_variant	Exon 5 of 22	ENST00000355112.8	NP_000048.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
BLM	ENST00000355112.8 link	c.1044G>A	p.Met348Ile	missense_variant	Exon 5 of 22	1	NM_000057.4	ENSP00000347232.3

Frequencies

GnomAD3 genomes

AF:

0.0000789

AC:

AN:

152122

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00231

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:

0.000243

AC:

AN:

250878

AF XY:

0.000155

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000828

AC:

121

AN:

1461678

Hom.:

Cov.:

AF XY:

0.0000674

AC XY:

AN XY:

727138

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33478

American (AMR)

AF:

0.00

AC:

AN:

44720

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26130

East Asian (EAS)

AF:

0.00280

AC:

111

AN:

39674

South Asian (SAS)

AF:

0.0000116

AC:

AN:

86244

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53340

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00000450

AC:

AN:

1111938

Other (OTH)

AF:

0.0000662

AC:

AN:

60386

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.483

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:

0.0000788

AC:

AN:

152240

Hom.:

Cov.:

AF XY:

0.000107

AC XY:

AN XY:

74460

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41544

American (AMR)

AF:

0.00

AC:

AN:

15288

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00231

AC:

AN:

5184

South Asian (SAS)

AF:

0.00

AC:

AN:

4820

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10612

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68010

Other (OTH)

AF:

0.00

AC:

AN:

2108

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.513

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome 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

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.000140

ExAC

AF:

0.000231

AC:

Asia WGS

AF:

0.00115

AC:

AN:

3478

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3Benign:4

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not specified

Uncertain:2

Jun 23, 2025

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: BLM c.1044G>A (p.Met348Ile) results in a conservative amino acid change in the encoded protein sequence. Algorithms developed to predict the effect of missense changes on protein structure and function all suggest that this variant is likely to be tolerated. The variant allele was found at a frequency of 0.00024 in 250878 control chromosomes (gnomAD). This frequency is not significantly higher than estimated for a pathogenic variant in BLM causing Bloom Syndrome (0.00024 vs 0.0035), allowing no conclusion about variant significance. c.1044G>A has been observed in individuals affected with Melanoma, Urothelial carcinoma or Schuurs-Hoeijmakers syndrome (Luo_2020, Yang_2021, Ohkawa_2021). These reports do not provide unequivocal conclusions about association of the variant with Bloom Syndrome. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 23292937, 32083130, 33588785, 34341476). ClinVar contains an entry for this variant (Variation ID: 413284). Based on the evidence outlined above, the variant was classified as uncertain significance. -

May 06, 2022

Genetic Services Laboratory, University of Chicago

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

DNA sequence analysis of the BLM gene demonstrated a sequence change, c.1044G>A, in exon 5 that results in an amino acid change, p.Met348Ile. This sequence change has been described in the gnomAD database with a frequency of 0.33% in the East Asian subpopulation (dbSNP rs184657475). The p.Met348Ile change affects a poorly conserved amino acid residue located in a domain of the BLM protein that is not known to be functional. The p.Met348Ile substitution appears to be benign using several in-silico pathogenicity prediction tools (SIFT, PolyPhen2, Align GVGD, REVEL). This sequence change does not appear to have been previously described in individuals with BLM-related disorders. Due to insufficient evidences and the lack of functional studies, the clinical significance of the p.Met348Ile change remains unknown at this time. -

Hereditary breast ovarian cancer syndrome

Uncertain:1

May 01, 2019

Cancer Genomics Group, Japanese Foundation For Cancer Research

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:research

- -

BLM-related disorder

Benign:1

Sep 01, 2022

PreventionGenetics, part of Exact Sciences

Significance:Likely benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Bloom syndrome

Benign:1

Feb 02, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

not provided

Benign:1

Jun 29, 2023

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Hereditary cancer-predisposing syndrome

Benign:1

Nov 14, 2022

Ambry Genetics

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This 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

0.13

BayesDel_addAF

Benign

-0.61

BayesDel_noAF

Benign

-0.65

CADD

Benign

5.2

(source)

DANN

Benign

0.68

DEOGEN2

Benign

0.084

T;.

Eigen

Benign

-1.1

Eigen_PC

Benign

-1.1

FATHMM_MKL

Benign

0.038

LIST_S2

Benign

0.48

T;T

M_CAP

Benign

0.016

MetaRNN

Benign

0.0045

T;T

MetaSVM

Benign

-1.0

MutationAssessor

Benign

1.5

L;.

PhyloP100

0.17

PrimateAI

Benign

0.28

PROVEAN

Benign

-0.78

N;N

REVEL

Benign

0.022

Sift

Uncertain

0.025

D;T

Sift4G

Benign

0.44

T;T

Polyphen

0.15

B;.

Vest4

0.19

MutPred

0.17

Gain of methylation at K347 (P = 0.0223);Gain of methylation at K347 (P = 0.0223);

MVP

0.60

MPC

0.098

ClinPred

0.014

GERP RS

-0.88

Varity_R

0.067

gMVP

0.071

Mutation Taster

=91/9

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

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over