15-90751921-T-G

Position:

chr15-90751921-T-G

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2BP4_StrongBP6

The NM_000057.4(BLM):c.934T>G(p.Ser312Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000316 in 1,612,378 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000046 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000030 ( 0 hom. )

Consequence

BLM
NM_000057.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4B:2

Conservation

PhyloP100: -0.110

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 Likely_benign. Variant got -3 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.04663652).

BP6

Variant 15-90751921-T-G is Benign according to our data. Variant chr15-90751921-T-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 454170.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=2, Uncertain_significance=3}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BLM	NM_000057.4 linkuse as main transcript	c.934T>G	p.Ser312Ala	missense_variant	4/22	ENST00000355112.8	NP_000048.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BLM	ENST00000355112.8 linkuse as main transcript	c.934T>G	p.Ser312Ala	missense_variant	4/22	1	NM_000057.4	ENSP00000347232	P2

Frequencies

GnomAD3 genomes

AF:

0.0000460

AC:

AN:

152236

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000482

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000131

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:

0.0000441

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000478

AC:

AN:

251132

Hom.:

AF XY:

0.0000516

AC XY:

AN XY:

135756

show subpopulations

Gnomad AFR exome

AF:

0.0000616

Gnomad AMR exome

AF:

0.000145

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:

0.0000528

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000301

AC:

AN:

1460142

Hom.:

Cov.:

AF XY:

0.0000220

AC XY:

AN XY:

726496

show subpopulations

Gnomad4 AFR exome

AF:

0.000269

Gnomad4 AMR exome

AF:

0.000134

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000252

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000243

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000460

AC:

AN:

152236

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74368

show subpopulations

Gnomad4 AFR

AF:

0.0000482

Gnomad4 AMR

AF:

0.000131

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000441

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000434

Hom.:

Bravo

AF:

0.0000718

TwinsUK

AF:

0.00

AC:

ALSPAC

AF:

0.000259

AC:

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.0000659

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:4Benign:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Bloom syndrome

Uncertain:2

Uncertain significance, no assertion criteria provided	clinical testing	Natera, Inc.	Sep 16, 2020	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Oct 06, 2022	This sequence change replaces serine, which is neutral and polar, with alanine, which is neutral and non-polar, at codon 312 of the BLM protein (p.Ser312Ala). This variant is present in population databases (rs372454889, gnomAD 0.01%). 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: 454170). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt BLM protein function. 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. -

not provided

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Oct 04, 2024	Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis indicates that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 35264596, 33606809) -
Uncertain significance, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Jul 12, 2023	In the published literature, this variant has been reported in at least one individual with breast cancer (PMIDs: 33606809 (2021) and 35264596 (2022)). The frequency of this variant in the general population, 0.00014 (5/35414 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

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Mendelics

Sep 11, 2024

This variant is considered likely benign or benign based on one or more of the following: it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease, and/or has normal protein function, and/or has lack of segregation with disease, and/or has been detected in co-occurrence with known pathogenic variant, and/or has lack of disease association in case-control studies, and/or is located in a region inconsistent with a known cause of pathogenicity. -

Hereditary cancer-predisposing syndrome

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Jan 29, 2024

This 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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.061

BayesDel_addAF

Benign

-0.48

BayesDel_noAF

Benign

-0.67

CADD

Benign

1.1

DANN

Benign

0.62

DEOGEN2

Benign

0.057

T;.

Eigen

Benign

-1.6

Eigen_PC

Benign

-1.6

FATHMM_MKL

Benign

0.024

LIST_S2

Benign

0.37

T;T

M_CAP

Benign

0.0067

MetaRNN

Benign

0.047

T;T

MetaSVM

Benign

-1.0

MutationAssessor

Benign

0.35

N;.

MutationTaster

Benign

1.0

N;N

PrimateAI

Benign

0.28

PROVEAN

Benign

-0.40

N;N

REVEL

Benign

0.022

Sift

Benign

0.50

T;T

Sift4G

Benign

0.80

T;T

Polyphen

0.0

B;.

Vest4

0.10

MVP

0.58

MPC

0.075

ClinPred

0.029

GERP RS

-6.8

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

2.8

Varity_R

0.019

gMVP

0.090

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.

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