rs56257041

Variant summary

Our verdict is Benign. Variant got -8 ACMG points: 2P and 10B. PM2BP4_StrongBP6BP7BS1

The NM_000057.4(BLM):​c.1467G>A​(p.Arg489Arg) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000149 in 1,613,974 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.00034 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00013 ( 0 hom. )

Consequence

BLM
NM_000057.4 synonymous

Scores

2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:6

Conservation

PhyloP100: -0.0920
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]

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ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -8 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.81).
BP6
Variant 15-90760840-G-A is Benign according to our data. Variant chr15-90760840-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 236801.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=4, Benign=1, Uncertain_significance=2}.
BP7
Synonymous conserved (PhyloP=-0.092 with no splicing effect.
BS1
Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.000335 (51/152184) while in subpopulation AFR AF= 0.00101 (42/41522). AF 95% confidence interval is 0.000769. There are 0 homozygotes in gnomad4. There are 24 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
BLMNM_000057.4 linkc.1467G>A p.Arg489Arg synonymous_variant Exon 7 of 22 ENST00000355112.8 NP_000048.1 P54132

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
BLMENST00000355112.8 linkc.1467G>A p.Arg489Arg synonymous_variant Exon 7 of 22 1 NM_000057.4 ENSP00000347232.3 P54132

Frequencies

GnomAD3 genomes
AF:
0.000322
AC:
49
AN:
152066
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.000966
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:
0.000118
Gnomad OTH
AF:
0.000479
GnomAD3 exomes
AF:
0.000188
AC:
47
AN:
250324
Hom.:
0
AF XY:
0.000177
AC XY:
24
AN XY:
135408
show subpopulations
Gnomad AFR exome
AF:
0.00124
Gnomad AMR exome
AF:
0.000289
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000124
Gnomad OTH exome
AF:
0.000492
GnomAD4 exome
AF:
0.000130
AC:
190
AN:
1461790
Hom.:
0
Cov.:
32
AF XY:
0.000139
AC XY:
101
AN XY:
727184
show subpopulations
Gnomad4 AFR exome
AF:
0.00149
Gnomad4 AMR exome
AF:
0.000246
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000116
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000890
Gnomad4 OTH exome
AF:
0.000381
GnomAD4 genome
AF:
0.000335
AC:
51
AN:
152184
Hom.:
0
Cov.:
32
AF XY:
0.000323
AC XY:
24
AN XY:
74390
show subpopulations
Gnomad4 AFR
AF:
0.00101
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.000118
Gnomad4 OTH
AF:
0.000474
Alfa
AF:
0.000148
Hom.:
1
Bravo
AF:
0.000355
Asia WGS
AF:
0.00144
AC:
5
AN:
3478
EpiCase
AF:
0.000109
EpiControl
AF:
0.000296

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:2Benign:6
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Bloom syndrome Uncertain:1Benign:2
Jan 13, 2018
Illumina Laboratory Services, Illumina
Significance: Uncertain significance
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, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

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

- -

May 20, 2019
Natera, Inc.
Significance: Likely benign
Review Status: no assertion criteria provided
Collection Method: clinical testing

- -

not provided Uncertain:1Benign:1
May 02, 2018
Eurofins Ntd Llc (ga)
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Apr 01, 2024
CeGaT Center for Human Genetics Tuebingen
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

BLM: BP4, BP7 -

Hereditary cancer-predisposing syndrome Benign:2
Jan 15, 2022
Sema4, Sema4
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: curation

- -

Apr 18, 2017
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. -

not specified Benign:1
Dec 17, 2020
Genetic Services Laboratory, University of Chicago
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.81
CADD
Benign
0.67
DANN
Benign
0.37
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs56257041; hg19: chr15-91304070; COSMIC: COSV104665683; COSMIC: COSV104665683; API