rs2227934

Variant summary

Our verdict is Benign. The variant received -21 ACMG points: 0P and 21B. BP4_StrongBP6_Very_StrongBP7BA1

The NM_000057.4(BLM):​c.3531C>A​(p.Ala1177Ala) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.168 in 1,613,558 control chromosomes in the GnomAD database, including 23,763 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★★). Synonymous variant affecting the same amino acid position (i.e. A1177A) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.15 ( 1904 hom., cov: 32)
Exomes 𝑓: 0.17 ( 21859 hom. )

Consequence

BLM
NM_000057.4 synonymous

Scores

2

Clinical Significance

Benign criteria provided, multiple submitters, no conflicts B:13

Conservation

PhyloP100: -1.00

Publications

30 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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -21 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.53).
BP6
Variant 15-90803693-C-A is Benign according to our data. Variant chr15-90803693-C-A is described in ClinVar as Benign. ClinVar VariationId is 92395.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BP7
Synonymous conserved (PhyloP=-1 with no splicing effect.
BA1
GnomAd4 highest subpopulation (NFE) allele frequency at 95% confidence interval = 0.184 is higher than 0.05.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
BLMNM_000057.4 linkc.3531C>A p.Ala1177Ala synonymous_variant Exon 18 of 22 ENST00000355112.8 NP_000048.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
BLMENST00000355112.8 linkc.3531C>A p.Ala1177Ala synonymous_variant Exon 18 of 22 1 NM_000057.4 ENSP00000347232.3

Frequencies

GnomAD3 genomes
AF:
0.154
AC:
23353
AN:
151944
Hom.:
1907
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.121
Gnomad AMI
AF:
0.0965
Gnomad AMR
AF:
0.111
Gnomad ASJ
AF:
0.171
Gnomad EAS
AF:
0.178
Gnomad SAS
AF:
0.0925
Gnomad FIN
AF:
0.146
Gnomad MID
AF:
0.161
Gnomad NFE
AF:
0.187
Gnomad OTH
AF:
0.149
GnomAD2 exomes
AF:
0.151
AC:
38074
AN:
251328
AF XY:
0.150
show subpopulations
Gnomad AFR exome
AF:
0.121
Gnomad AMR exome
AF:
0.0884
Gnomad ASJ exome
AF:
0.166
Gnomad EAS exome
AF:
0.180
Gnomad FIN exome
AF:
0.146
Gnomad NFE exome
AF:
0.187
Gnomad OTH exome
AF:
0.156
GnomAD4 exome
AF:
0.170
AC:
248242
AN:
1461496
Hom.:
21859
Cov.:
33
AF XY:
0.168
AC XY:
122051
AN XY:
727062
show subpopulations
African (AFR)
AF:
0.117
AC:
3902
AN:
33470
American (AMR)
AF:
0.0935
AC:
4180
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.165
AC:
4318
AN:
26122
East Asian (EAS)
AF:
0.177
AC:
7015
AN:
39680
South Asian (SAS)
AF:
0.0891
AC:
7683
AN:
86250
European-Finnish (FIN)
AF:
0.147
AC:
7830
AN:
53408
Middle Eastern (MID)
AF:
0.138
AC:
798
AN:
5768
European-Non Finnish (NFE)
AF:
0.182
AC:
202656
AN:
1111698
Other (OTH)
AF:
0.163
AC:
9860
AN:
60380
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.457
Heterozygous variant carriers
0
10932
21864
32797
43729
54661
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
6894
13788
20682
27576
34470
<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:
0.154
AC:
23361
AN:
152062
Hom.:
1904
Cov.:
32
AF XY:
0.150
AC XY:
11157
AN XY:
74322
show subpopulations
African (AFR)
AF:
0.121
AC:
5004
AN:
41494
American (AMR)
AF:
0.111
AC:
1691
AN:
15264
Ashkenazi Jewish (ASJ)
AF:
0.171
AC:
595
AN:
3470
East Asian (EAS)
AF:
0.179
AC:
927
AN:
5178
South Asian (SAS)
AF:
0.0934
AC:
450
AN:
4818
European-Finnish (FIN)
AF:
0.146
AC:
1537
AN:
10548
Middle Eastern (MID)
AF:
0.156
AC:
46
AN:
294
European-Non Finnish (NFE)
AF:
0.187
AC:
12708
AN:
67972
Other (OTH)
AF:
0.149
AC:
315
AN:
2112
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.506
Heterozygous variant carriers
0
1022
2044
3067
4089
5111
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Genome Hom
Variant carriers
0
254
508
762
1016
1270
<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:
0.170
Hom.:
3610
Bravo
AF:
0.149
Asia WGS
AF:
0.136
AC:
474
AN:
3478

ClinVar

Significance: Benign
Submissions summary: Benign:13
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Bloom syndrome Benign:6
Jan 13, 2018
Illumina Laboratory Services, Illumina
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Jul 01, 2021
Genome-Nilou Lab
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Nov 15, 2024
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Mar 28, 2017
Natera, Inc.
Significance:Benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Jul 07, 2023
KCCC/NGS Laboratory, Kuwait Cancer Control Center
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Feb 04, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not specified Benign:3
Mar 28, 2016
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant identified in a genome or exome case(s) and assessed due to predicted null impact of the variant or pathogenic assertions in the literature or databases. Disclaimer: This variant has not undergone full assessment. The following are preliminary notes: Frequency -

-
Genetic Services Laboratory, University of Chicago
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

Likely benign based on allele frequency in 1000 Genomes Project or ESP global frequency and its presence in a patient with a rare or unrelated disease phenotype. NOT Sanger confirmed. -

Jul 29, 2013
Eurofins Ntd Llc (ga)
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Benign:2
Mar 03, 2015
GeneDx
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

-
Breakthrough Genomics, Breakthrough Genomics
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:not provided

- -

BLM-related disorder Benign:1
Nov 15, 2022
PreventionGenetics, part of Exact Sciences
Significance:Benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

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

Hereditary cancer-predisposing syndrome Benign:1
Aug 10, 2016
Ambry Genetics
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This alteration is classified as 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
BayesDel_noAF
Benign
-0.53
CADD
Benign
3.0
DANN
Benign
0.50
PhyloP100
-1.0
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Mutation Taster
=100/0
polymorphism (auto)

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

Other links and lift over

dbSNP: rs2227934; hg19: chr15-91346923; COSMIC: COSV61922667; API