15-90794275-C-T

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_000057.4(BLM):c.3128C>T(p.Ala1043Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000687 in 1,454,802 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A1043D) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 6.9e-7 ( 0 hom. )

Consequence

BLM
NM_000057.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 7.70

Publications

11 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:

ENSG00000300894 (HGNC:):

ENSG00000300894 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
BLM	NM_000057.4 link	c.3128C>T	p.Ala1043Val	missense_variant	Exon 16 of 22	ENST00000355112.8	NP_000048.1	P54132

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
BLM	ENST00000355112.8 link	c.3128C>T	p.Ala1043Val	missense_variant	Exon 16 of 22	1	NM_000057.4	ENSP00000347232.3		P54132

Frequencies

GnomAD3 genomes

Cov.:

GnomAD2 exomes

AF:

0.00000401

AC:

AN:

249668

AF XY:

0.00

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000553

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

6.87e-7

AC:

AN:

1454802

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

723562

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33388

American (AMR)

AF:

0.00

AC:

AN:

44428

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26020

East Asian (EAS)

AF:

0.0000255

AC:

AN:

39238

South Asian (SAS)

AF:

0.00

AC:

AN:

84790

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53082

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5744

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1108114

Other (OTH)

AF:

0.00

AC:

AN:

59998

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.575

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

Cov.:

Alfa

AF:

0.00

Hom.:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Bloom syndrome

Uncertain:1

Feb 19, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 1043 of the BLM protein (p.Ala1043Val). This variant is present in population databases (no rsID available, gnomAD 0.006%). This variant has not been reported in the literature in individuals affected with BLM-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). 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

Jun 07, 2021

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.A1043V variant (also known as c.3128C>T), located in coding exon 15 of the BLM gene, results from a C to T substitution at nucleotide position 3128. The alanine at codon 1043 is replaced by valine, an amino acid with similar properties. This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.29

BayesDel_addAF

Benign

-0.010

BayesDel_noAF

Uncertain

-0.080

CADD

Uncertain

(source)

DANN

Uncertain

1.0

DEOGEN2

Benign

0.31

T;.

Eigen

Uncertain

0.26

Eigen_PC

Uncertain

0.40

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Uncertain

0.95

D;D

M_CAP

Benign

0.052

MetaRNN

Uncertain

0.48

T;T

MetaSVM

Benign

-0.37

MutationAssessor

Uncertain

2.9

M;.

PhyloP100

7.7

PrimateAI

Uncertain

0.63

PROVEAN

Uncertain

-2.6

D;D

REVEL

Uncertain

0.41

Sift

Benign

0.095

T;D

Sift4G

Benign

0.093

T;T

Polyphen

0.076

B;.

Vest4

0.55

MutPred

0.44

Loss of helix (P = 0.1299);Loss of helix (P = 0.1299);

MVP

0.85

MPC

0.29

ClinPred

0.90

GERP RS

5.5

Varity_R

0.48

gMVP

0.71

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

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

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over