chr15-90784997-C-T

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 2P and 6B. PM2BP4_StrongBP6BP7

The NM_000057.4(BLM):​c.2739C>T​(p.Leu913=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000142 in 1,613,996 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). Synonymous variant affecting the same amino acid position (i.e. L913L) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00011 ( 0 hom., cov: 31)
Exomes 𝑓: 0.00015 ( 0 hom. )

Consequence

BLM
NM_000057.4 synonymous

Scores

2

Clinical Significance

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

Conservation

PhyloP100: -3.19
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 Likely_benign. Variant got -4 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.75).
BP6
Variant 15-90784997-C-T is Benign according to our data. Variant chr15-90784997-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 317407.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=1, Likely_benign=6}.
BP7
Synonymous conserved (PhyloP=-3.19 with no splicing effect.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
BLMNM_000057.4 linkuse as main transcriptc.2739C>T p.Leu913= synonymous_variant 14/22 ENST00000355112.8

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
BLMENST00000355112.8 linkuse as main transcriptc.2739C>T p.Leu913= synonymous_variant 14/221 NM_000057.4 P2

Frequencies

GnomAD3 genomes
AF:
0.000105
AC:
16
AN:
152112
Hom.:
0
Cov.:
31
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000327
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:
0.000162
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.000175
AC:
44
AN:
251458
Hom.:
0
AF XY:
0.000132
AC XY:
18
AN XY:
135906
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000809
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:
0.0000967
Gnomad OTH exome
AF:
0.000815
GnomAD4 exome
AF:
0.000146
AC:
213
AN:
1461884
Hom.:
0
Cov.:
31
AF XY:
0.000143
AC XY:
104
AN XY:
727246
show subpopulations
Gnomad4 AFR exome
AF:
0.0000299
Gnomad4 AMR exome
AF:
0.000715
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:
0.000149
Gnomad4 OTH exome
AF:
0.000215
GnomAD4 genome
AF:
0.000105
AC:
16
AN:
152112
Hom.:
0
Cov.:
31
AF XY:
0.0000538
AC XY:
4
AN XY:
74288
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.000327
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.000162
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000823
Hom.:
0
Bravo
AF:
0.000227
EpiCase
AF:
0.000164
EpiControl
AF:
0.000119

ClinVar

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

Submissions by phenotype

Bloom syndrome Uncertain:1Benign:2
Uncertain significance, criteria provided, single submitterclinical testingIllumina Laboratory Services, IlluminaJan 12, 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, 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. -
Likely benign, criteria provided, single submitterclinical testingInvitaeJan 31, 2024- -
Likely benign, no assertion criteria providedclinical testingNatera, Inc.Aug 09, 2017- -
not specified Benign:2
Likely benign, criteria provided, single submitterclinical testingGenetic Services Laboratory, University of ChicagoJul 22, 2021- -
Likely benign, criteria provided, single submitterclinical testingWomen's Health and Genetics/Laboratory Corporation of America, LabCorpOct 10, 2019- -
Hereditary cancer-predisposing syndrome Benign:2
Likely benign, criteria provided, single submitterclinical testingAmbry GeneticsMar 08, 2017This 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 submittercurationSema4, Sema4Jan 17, 2022- -
not provided Benign:1
Likely benign, criteria provided, single submitterclinical testingCeGaT Center for Human Genetics TuebingenSep 01, 2022BLM: BP4, BP7 -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.75
CADD
Benign
0.12
DANN
Benign
0.50
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.8

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

LitVar

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

Other links and lift over

dbSNP: rs759223856; hg19: chr15-91328227; API