rs138542210

Variant summary

Our verdict is Benign. The variant received -13 ACMG points: 0P and 13B. BP4_StrongBP6BS1BS2

The NM_000057.4(BLM):​c.178T>A​(p.Leu60Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000158 in 1,612,296 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts a benign outcome for this variant. 15/22 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 0.00014 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00016 ( 2 hom. )

Consequence

BLM
NM_000057.4 missense

Scores

1
2
16

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3B:7O:1

Conservation

PhyloP100: 0.226

Publications

8 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 -13 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.0064494014).
BP6
Variant 15-90749446-T-A is Benign according to our data. Variant chr15-90749446-T-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 133710.
BS1
Variant frequency is greater than expected in population eas. GnomAd4 allele frequency = 0.000138 (21/152316) while in subpopulation EAS AF = 0.00405 (21/5180). AF 95% confidence interval is 0.00272. There are 0 homozygotes in GnomAd4. There are 15 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.
BS2
High Homozygotes in GnomAdExome4 at 2 AR,AD gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
BLMNM_000057.4 linkc.178T>A p.Leu60Ile missense_variant Exon 3 of 22 ENST00000355112.8 NP_000048.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
BLMENST00000355112.8 linkc.178T>A p.Leu60Ile missense_variant Exon 3 of 22 1 NM_000057.4 ENSP00000347232.3

Frequencies

GnomAD3 genomes
AF:
0.000138
AC:
21
AN:
152198
Hom.:
0
Cov.:
32
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:
0.00404
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:
0.000264
AC:
66
AN:
250406
AF XY:
0.000280
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00343
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000177
Gnomad OTH exome
AF:
0.000164
GnomAD4 exome
AF:
0.000160
AC:
234
AN:
1459980
Hom.:
2
Cov.:
31
AF XY:
0.000180
AC XY:
131
AN XY:
726484
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33434
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26120
East Asian (EAS)
AF:
0.00572
AC:
227
AN:
39682
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86228
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53414
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5762
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1110290
Other (OTH)
AF:
0.000116
AC:
7
AN:
60328
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.487
Heterozygous variant carriers
0
16
32
47
63
79
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
4
8
12
16
20
<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:
0.000138
AC:
21
AN:
152316
Hom.:
0
Cov.:
32
AF XY:
0.000201
AC XY:
15
AN XY:
74480
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41568
American (AMR)
AF:
0.00
AC:
0
AN:
15308
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00405
AC:
21
AN:
5180
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10616
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68030
Other (OTH)
AF:
0.00
AC:
0
AN:
2110
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.492
Heterozygous variant carriers
0
2
4
5
7
9
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<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:
0.000303
Hom.:
0
Bravo
AF:
0.000136
ExAC
AF:
0.000313
AC:
38
Asia WGS
AF:
0.00173
AC:
6
AN:
3478

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:3Benign:7Other:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Bloom syndrome Benign:3
Jan 13, 2018
Illumina Laboratory Services, Illumina
Significance:Likely 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 likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

Jan 29, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Aug 06, 2019
Natera, Inc.
Significance:Benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

not specified Uncertain:1Other:1
Sep 19, 2013
ITMI
Significance:not provided
Review Status:no classification provided
Collection Method:reference population

- -

Sep 09, 2019
Genetic Services Laboratory, University of Chicago
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Hereditary cancer-predisposing syndrome Benign:2
Dec 17, 2020
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. -

Jan 19, 2022
Sema4, Sema4
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:curation

- -

Microcephaly Uncertain:1
-
Department of Pediatrics, Samsung Medical Center, Samsung Medical Center
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:research

- -

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
Oct 13, 2020
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). -

not provided Benign:1
Apr 22, 2021
Quest Diagnostics Nichols Institute San Juan Capistrano
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
0.10
BayesDel_addAF
Benign
-0.41
T
BayesDel_noAF
Benign
-0.36
CADD
Benign
17
DANN
Uncertain
0.99
DEOGEN2
Benign
0.29
T;.
Eigen
Benign
-0.044
Eigen_PC
Benign
-0.25
FATHMM_MKL
Benign
0.18
N
LIST_S2
Benign
0.75
T;T
M_CAP
Benign
0.062
D
MetaRNN
Benign
0.0064
T;T
MetaSVM
Benign
-0.81
T
MutationAssessor
Uncertain
2.4
M;.
PhyloP100
0.23
PrimateAI
Benign
0.43
T
PROVEAN
Benign
-0.90
N;N
REVEL
Benign
0.099
Sift
Pathogenic
0.0
D;D
Sift4G
Benign
0.12
T;T
Polyphen
0.99
D;.
Vest4
0.25
MVP
0.83
MPC
0.15
ClinPred
0.12
T
GERP RS
0.57
Varity_R
0.43
gMVP
0.049
Mutation Taster
=98/2
polymorphism

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: rs138542210; hg19: chr15-91292676; COSMIC: COSV105909954; API