15-90747490-C-T

Variant names:

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_000057.4(BLM):c.98C>T(p.Ser33Leu) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000138 in 1,592,964 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 31)

Exomes 𝑓: 0.000011 ( 0 hom. )

Consequence

BLM
NM_000057.4 missense, splice_region

Scores

Splicing: ADA: 0.002991

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:5O:1

Conservation

PhyloP100: -0.367

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 0 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.06889522).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
BLM	NM_000057.4 link	c.98C>T	p.Ser33Leu	missense_variant, splice_region_variant	Exon 2 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.98C>T	p.Ser33Leu	missense_variant, splice_region_variant	Exon 2 of 22	1	NM_000057.4	ENSP00000347232.3		P54132

Frequencies

GnomAD3 genomes

AF:

0.0000394

AC:

AN:

152136

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000483

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000193

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000441

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000173

AC:

AN:

231170

Hom.:

AF XY:

0.00000803

AC XY:

AN XY:

124550

show subpopulations

Gnomad AFR exome

AF:

0.000136

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.0000480

Gnomad NFE exome

AF:

0.00000995

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000111

AC:

AN:

1440710

Hom.:

Cov.:

AF XY:

0.00000977

AC XY:

AN XY:

716214

show subpopulations

Gnomad4 AFR exome

AF:

0.0000302

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.0000190

Gnomad4 NFE exome

AF:

0.0000128

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000394

AC:

AN:

152254

Hom.:

Cov.:

AF XY:

0.0000403

AC XY:

AN XY:

74438

show subpopulations

Gnomad4 AFR

AF:

0.0000481

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000193

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000441

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000712

Hom.:

Bravo

AF:

0.0000151

ExAC

AF:

0.00000825

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5Other:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Bloom syndrome

Uncertain:2

Nov 24, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces serine, which is neutral and polar, with leucine, which is neutral and non-polar, at codon 33 of the BLM protein (p.Ser33Leu). This variant is present in population databases (rs139282091, gnomAD 0.005%). This variant has not been reported in the literature in individuals affected with BLM-related conditions. ClinVar contains an entry for this variant (Variation ID: 133703). An algorithm developed to predict the effect of missense changes on protein structure and function outputs the following: PolyPhen-2: "Benign". The leucine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. RNA analysis performed to evaluate the impact of this missense change on mRNA splicing indicates it does not significantly alter splicing (internal data). 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. -

Nov 17, 2018

Natera, Inc.

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

not provided

Uncertain:2

Nov 03, 2021

Institute for Clinical Genetics, University Hospital TU Dresden, University Hospital TU Dresden

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Aug 16, 2023

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In the published literature, this variant has been reported in unaffected individuals (PMID: 24728327 (20104)). The frequency of this variant in the general population, 0.000027 (7/262566 chromosomes (Genome Aggregation Database, http://gnomad.broadinstitute.org)), is uninformative in the assessment of its pathogenicity. Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded predictions that this variant is benign. Based on the available information, we are unable to determine the clinical significance of this variant. -

Hereditary cancer-predisposing syndrome

Uncertain:1

May 02, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.S33L variant (also known as c.98C>T), located in coding exon 1 of the BLM gene, results from a C to T substitution at nucleotide position 98. The amino acid change results in serine to leucine at codon 33, an amino acid with dissimilar properties. This amino acid position is not well conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

not specified

Other:1

Sep 19, 2013

ITMI

Significance: not provided

Review Status: no classification provided

Collection Method: reference population

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.067

BayesDel_addAF

Benign

-0.38

BayesDel_noAF

Benign

-0.60

CADD

Benign

DANN

Benign

0.97

DEOGEN2

Benign

0.093

T;.

Eigen

Benign

-0.60

Eigen_PC

Benign

-0.49

FATHMM_MKL

Benign

0.27

LIST_S2

Benign

0.73

T;T

MetaRNN

Benign

0.069

T;T

MetaSVM

Benign

-1.0

MutationAssessor

Benign

0.89

L;.

PrimateAI

Benign

0.29

PROVEAN

Benign

-1.6

N;N

REVEL

Benign

0.027

Sift

Benign

0.19

T;T

Sift4G

Benign

0.12

T;T

Polyphen

0.0070

B;.

Vest4

0.18

MVP

0.70

MPC

0.079

ClinPred

0.089

GERP RS

2.7

Varity_R

0.044

gMVP

0.073

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Benign

0.0030

dbscSNV1_RF

Benign

0.088

SpliceAI score (max)

0.090

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over