rs750532596

Positions:

chr15-90803718-A-G

Variant summary

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

The NM_000057.4(BLM):c.3556A>G(p.Lys1186Glu) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000026 in 1,613,804 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/23 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 Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000025 ( 0 hom. )

Consequence

BLM
NM_000057.4 missense, splice_region

Scores

Splicing: ADA: 0.02059

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:6B:1

Conservation

PhyloP100: 1.97

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:

BLM (HGNC:):

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=0.09259218).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BLM	NM_000057.4 linkuse as main transcript	c.3556A>G	p.Lys1186Glu	missense_variant, splice_region_variant	18/22	ENST00000355112.8	NP_000048.1	P54132

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BLM	ENST00000355112.8 linkuse as main transcript	c.3556A>G	p.Lys1186Glu	missense_variant, splice_region_variant	18/22	1	NM_000057.4	ENSP00000347232.3		P54132

Frequencies

GnomAD3 genomes

AF:

0.0000394

AC:

AN:

152246

Hom.:

Cov.:

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.000104

AC:

AN:

251152

Hom.:

AF XY:

0.0000884

AC XY:

AN XY:

135812

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000636

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:

0.00

Gnomad OTH exome

AF:

0.000654

GnomAD4 exome

AF:

0.0000246

AC:

AN:

1461558

Hom.:

Cov.:

AF XY:

0.0000261

AC XY:

AN XY:

727102

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.000693

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000450

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000394

AC:

AN:

152246

Hom.:

Cov.:

AF XY:

0.0000538

AC XY:

AN XY:

74388

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:

0.0000147

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000378

ExAC

AF:

0.000115

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:6Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Bloom syndrome

Uncertain:4

Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 28, 2024	This sequence change replaces lysine, which is basic and polar, with glutamic acid, which is acidic and polar, at codon 1186 of the BLM protein (p.Lys1186Glu). This variant is present in population databases (rs750532596, gnomAD 0.05%). 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: 567289). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant¬†is likely to be tolerated. RNA analysis performed to evaluate the impact of this missense change on mRNA splicing indicates it does not significantly alter splicing (Invitae). 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Fulgent Genetics, Fulgent Genetics	Oct 31, 2018	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Baylor Genetics	Nov 16, 2020	This variant was determined to be of uncertain significance according to ACMG Guidelines, 2015 [PMID:25741868]. -
Uncertain significance, criteria provided, single submitter	clinical testing	Mendelics	Jul 02, 2018	- -

Hereditary cancer-predisposing syndrome

Uncertain:1Benign:1

Uncertain significance, criteria provided, single submitter	curation	Sema4, Sema4	Dec 16, 2021	- -
Likely benign, criteria provided, single submitter	clinical testing	Ambry Genetics	Nov 23, 2021	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. -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Jun 23, 2023

In silico analysis supports that this missense variant does not alter protein structure/function; Observed in at least one individual with breast cancer in published literature (Guindalini et al., 2022); This variant is associated with the following publications: (PMID: 35264596) -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.17

BayesDel_addAF

Benign

-0.27

BayesDel_noAF

Benign

-0.28

CADD

Benign

DANN

Uncertain

1.0

DEOGEN2

Benign

0.23

Eigen

Benign

-0.096

Eigen_PC

Benign

0.029

FATHMM_MKL

Uncertain

0.92

LIST_S2

Benign

0.81

M_CAP

Benign

0.019

MetaRNN

Benign

0.093

MetaSVM

Benign

-0.95

MutationAssessor

Uncertain

2.5

PrimateAI

Benign

0.44

PROVEAN

Benign

-1.9

REVEL

Benign

0.13

Sift

Benign

0.077

Sift4G

Benign

0.10

Polyphen

0.051

Vest4

0.19

MutPred

0.62

Loss of ubiquitination at K1186 (P = 0.013);

MVP

0.81

MPC

0.21

ClinPred

0.087

GERP RS

5.7

Varity_R

0.47

gMVP

0.63

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Benign

0.021

dbscSNV1_RF

Benign

0.15

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