15-90811410-T-G

Variant summary

Our verdict is Benign. Variant got -20 ACMG points: 0P and 20B. BP4_StrongBP6_Very_StrongBS1BS2

The NM_000057.4(BLM):​c.4076+4T>G variant causes a splice donor region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00451 in 1,613,300 control chromosomes in the GnomAD database, including 38 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.0044 ( 5 hom., cov: 33)
Exomes 𝑓: 0.0045 ( 33 hom. )

Consequence

BLM
NM_000057.4 splice_donor_region, intron

Scores

2
Splicing: ADA: 0.00003625
2

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:18

Conservation

PhyloP100: -0.769
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 -20 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.93).
BP6
Variant 15-90811410-T-G is Benign according to our data. Variant chr15-90811410-T-G is described in ClinVar as [Likely_benign]. Clinvar id is 136520.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr15-90811410-T-G is described in Lovd as [Likely_benign].
BS1
Variant frequency is greater than expected in population amr. gnomad4 allele frequency = 0.00444 (677/152312) while in subpopulation AMR AF= 0.00732 (112/15302). AF 95% confidence interval is 0.00622. There are 5 homozygotes in gnomad4. There are 342 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck.
BS2
High Homozygotes in GnomAd4 at 5 AR gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
BLMNM_000057.4 linkuse as main transcriptc.4076+4T>G splice_donor_region_variant, intron_variant ENST00000355112.8 NP_000048.1

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
BLMENST00000355112.8 linkuse as main transcriptc.4076+4T>G splice_donor_region_variant, intron_variant 1 NM_000057.4 ENSP00000347232 P2

Frequencies

GnomAD3 genomes
AF:
0.00445
AC:
677
AN:
152194
Hom.:
5
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.000796
Gnomad AMI
AF:
0.00548
Gnomad AMR
AF:
0.00733
Gnomad ASJ
AF:
0.0360
Gnomad EAS
AF:
0.000192
Gnomad SAS
AF:
0.00228
Gnomad FIN
AF:
0.00754
Gnomad MID
AF:
0.0411
Gnomad NFE
AF:
0.00406
Gnomad OTH
AF:
0.0100
GnomAD3 exomes
AF:
0.00443
AC:
1112
AN:
250928
Hom.:
8
AF XY:
0.00471
AC XY:
640
AN XY:
135760
show subpopulations
Gnomad AFR exome
AF:
0.000555
Gnomad AMR exome
AF:
0.00327
Gnomad ASJ exome
AF:
0.0330
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00274
Gnomad FIN exome
AF:
0.00472
Gnomad NFE exome
AF:
0.00380
Gnomad OTH exome
AF:
0.00668
GnomAD4 exome
AF:
0.00452
AC:
6604
AN:
1460988
Hom.:
33
Cov.:
32
AF XY:
0.00463
AC XY:
3362
AN XY:
726850
show subpopulations
Gnomad4 AFR exome
AF:
0.00167
Gnomad4 AMR exome
AF:
0.00356
Gnomad4 ASJ exome
AF:
0.0331
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00266
Gnomad4 FIN exome
AF:
0.00375
Gnomad4 NFE exome
AF:
0.00405
Gnomad4 OTH exome
AF:
0.00742
GnomAD4 genome
AF:
0.00444
AC:
677
AN:
152312
Hom.:
5
Cov.:
33
AF XY:
0.00459
AC XY:
342
AN XY:
74484
show subpopulations
Gnomad4 AFR
AF:
0.000794
Gnomad4 AMR
AF:
0.00732
Gnomad4 ASJ
AF:
0.0360
Gnomad4 EAS
AF:
0.000193
Gnomad4 SAS
AF:
0.00228
Gnomad4 FIN
AF:
0.00754
Gnomad4 NFE
AF:
0.00406
Gnomad4 OTH
AF:
0.00992
Alfa
AF:
0.00481
Hom.:
3
Bravo
AF:
0.00483
Asia WGS
AF:
0.00346
AC:
12
AN:
3478
EpiCase
AF:
0.00600
EpiControl
AF:
0.00581

ClinVar

Significance: Benign/Likely benign
Submissions summary: Benign:18
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Bloom syndrome Benign:5
Benign, no assertion criteria providedclinical testingNatera, Inc.Apr 02, 2018- -
Benign, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpFeb 01, 2024- -
Benign, criteria provided, single submitterclinical testingARUP Laboratories, Molecular Genetics and Genomics, ARUP LaboratoriesApr 15, 2021- -
Likely benign, criteria provided, single submitterclinical testingMendelicsJul 02, 2018- -
Likely benign, criteria provided, single submitterclinical testingIllumina Laboratory Services, IlluminaJan 13, 2018This 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. -
not provided Benign:5
Likely benign, no assertion criteria providedclinical testingClinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center-- -
Benign, criteria provided, single submitterclinical testingWomen's Health and Genetics/Laboratory Corporation of America, LabCorpJun 12, 2016Variant summary: The c.4076+4T>G in a BLM gene is an intronic variant that alters a non-conserved nucleotide. 5/5 in silico tools via Alamut predict this variant to not affect normal splicing, however these predictions have yet to be confirmed by functional assay. The variant is present in control dataset of ExAC at a frequency of 0.0038 (458/119942 chrs tested, including 3 homozygous occurrences) which exceeds the estimated maximum allele frequency for a pathogenic allele in this gene (0.0035), suggesting that this variant is a likely polymorphism. The variant has been reported in affected with breast cancer in literature (Thompson_2012) without strong evidence of causality. Multiple clinical laboratories have classified the variant as "Benign. Taken together, the variant is classified as Benign. -
Likely benign, criteria provided, single submitterclinical testingCeGaT Center for Human Genetics TuebingenAug 01, 2024BLM: BP4, BS2 -
Likely benign, no assertion criteria providedclinical testingGenome Diagnostics Laboratory, University Medical Center Utrecht-- -
Likely benign, no assertion criteria providedclinical testingGenome Diagnostics Laboratory, Amsterdam University Medical Center-- -
not specified Benign:4
Benign, criteria provided, single submitterclinical testingEurofins Ntd Llc (ga)Jun 09, 2016- -
Benign, criteria provided, single submitterclinical testingGeneDxOct 24, 2013This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -
Benign, criteria provided, single submitterclinical testingGenetic Services Laboratory, University of ChicagoApr 28, 2020- -
Benign, criteria provided, single submitterclinical testingQuest Diagnostics Nichols Institute San Juan CapistranoMay 21, 2021- -
Hereditary cancer-predisposing syndrome Benign:3
Benign, criteria provided, single submittercurationSema4, Sema4Jul 20, 2020- -
Likely benign, criteria provided, single submitterclinical testingAmbry GeneticsSep 16, 2018This 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. -
Likely benign, criteria provided, single submitterclinical testingGeneKor MSAAug 01, 2018- -
BLM-related disorder Benign:1
Benign, no assertion criteria providedclinical testingPreventionGenetics, part of Exact SciencesJun 05, 2020This variant is classified as benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.93
CADD
Benign
2.3
DANN
Benign
0.34

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.000036
dbscSNV1_RF
Benign
0.018
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: rs183176301; hg19: chr15-91354640; COSMIC: COSV104665659; COSMIC: COSV104665659; API