15-90760269-C-T

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PP3_ModeratePP5

The NM_000057.4(BLM):c.1210C>T(p.Arg404Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000867 in 1,613,874 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R404Q) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000089 ( 0 hom. )

Consequence

BLM
NM_000057.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:4

Conservation

PhyloP100: 2.66

Publications

3 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

BLM links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.883

PP5

Variant 15-90760269-C-T is Pathogenic according to our data. Variant chr15-90760269-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 454068.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000057.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
BLM	NM_000057.4	MANE Select	c.1210C>T	p.Arg404Trp	missense	Exon 6 of 22	NP_000048.1
BLM	NM_001287246.2		c.1210C>T	p.Arg404Trp	missense	Exon 7 of 23	NP_001274175.1
BLM	NM_001287247.2		c.1210C>T	p.Arg404Trp	missense	Exon 6 of 20	NP_001274176.1

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
BLM	ENST00000355112.8	TSL:1 MANE Select	c.1210C>T	p.Arg404Trp	missense	Exon 6 of 22	ENSP00000347232.3
BLM	ENST00000560509.5	TSL:1	c.1210C>T	p.Arg404Trp	missense	Exon 6 of 20	ENSP00000454158.1
BLM	ENST00000559724.5	TSL:1	n.*134C>T		non_coding_transcript_exon	Exon 6 of 22	ENSP00000453359.1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152120

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000358

AC:

AN:

251400

AF XY:

0.0000294

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000116

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.0000462

Gnomad NFE exome

AF:

0.0000264

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000889

AC:

AN:

1461754

Hom.:

Cov.:

AF XY:

0.00000963

AC XY:

AN XY:

727188

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33474

American (AMR)

AF:

0.0000894

AC:

AN:

44722

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26134

East Asian (EAS)

AF:

0.00

AC:

AN:

39684

South Asian (SAS)

AF:

0.0000232

AC:

AN:

86252

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53414

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5726

European-Non Finnish (NFE)

AF:

0.00000630

AC:

AN:

1111958

Other (OTH)

AF:

0.00

AC:

AN:

60390

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.456

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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:

0.00000657

AC:

AN:

152120

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74298

show subpopulations

African (AFR)

AF:

0.0000241

AC:

AN:

41424

American (AMR)

AF:

0.00

AC:

AN:

15272

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5194

South Asian (SAS)

AF:

0.00

AC:

AN:

4832

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10586

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68022

Other (OTH)

AF:

0.00

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<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:

0.00

Hom.:

Bravo

AF:

0.00000378

ExAC

AF:

0.0000165

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1Uncertain:4

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Pathogenic:1Uncertain:1

Sep 11, 2024

GeneDx

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Observed in individuals with hereditary breast/ovarian or colorectal cancer (PMID: 32522261); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 32522261)

Sep 02, 2021

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Bloom syndrome

Uncertain:2

Sep 16, 2020

Natera, Inc.

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

Jan 17, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 404 of the BLM protein (p.Arg404Trp). This variant is present in population databases (rs770721765, gnomAD 0.01%). This missense change has been observed in individual(s) with a personal and/or family history of hereditary breast, ovarian, and/or colorectal cancer (PMID: 32522261). ClinVar contains an entry for this variant (Variation ID: 454068). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt BLM protein function with a positive predictive value of 80%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance.

Hereditary cancer-predisposing syndrome

Uncertain:1

Sep 16, 2023

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.R404W variant (also known as c.1210C>T), located in coding exon 5 of the BLM gene, results from a C to T substitution at nucleotide position 1210. The arginine at codon 404 is replaced by tryptophan, an amino acid with dissimilar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear.

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.57

BayesDel_addAF

Uncertain

0.13

BayesDel_noAF

Pathogenic

0.18

CADD

Pathogenic

(source)

DANN

Pathogenic

1.0

DEOGEN2

Uncertain

0.56

Eigen

Pathogenic

0.73

Eigen_PC

Pathogenic

0.70

FATHMM_MKL

Uncertain

0.93

LIST_S2

Uncertain

0.93

M_CAP

Uncertain

0.12

MetaRNN

Pathogenic

0.88

MetaSVM

Uncertain

-0.15

MutationAssessor

Uncertain

2.8

PhyloP100

2.7

PrimateAI

Benign

0.43

PROVEAN

Pathogenic

-4.8

REVEL

Uncertain

0.52

Sift

Pathogenic

0.0

Sift4G

Uncertain

0.0020

Polyphen

1.0

Vest4

0.79

MutPred

0.72

Loss of solvent accessibility (P = 0.0468)

MVP

0.87

MPC

0.49

ClinPred

0.91

GERP RS

6.0

Varity_R

0.79

gMVP

0.57

Mutation Taster

=56/44

polymorphism

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.19

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over