15-90804177-T-C

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_000057.4(BLM):​c.3569T>C​(p.Met1190Thr) variant causes a missense change. The variant allele was found at a frequency of 0.00000821 in 1,461,550 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. 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. M1190V) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 0.0000082 ( 0 hom. )

Consequence

BLM
NM_000057.4 missense

Scores

1
18

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 5.12

Publications

0 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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -2 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.21958566).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
BLMNM_000057.4 linkc.3569T>C p.Met1190Thr missense_variant Exon 19 of 22 ENST00000355112.8 NP_000048.1 P54132

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
BLMENST00000355112.8 linkc.3569T>C p.Met1190Thr missense_variant Exon 19 of 22 1 NM_000057.4 ENSP00000347232.3 P54132

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD2 exomes
AF:
0.00000797
AC:
2
AN:
251006
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:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000821
AC:
12
AN:
1461550
Hom.:
0
Cov.:
32
AF XY:
0.00000688
AC XY:
5
AN XY:
727100
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33472
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26132
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39690
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86252
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53412
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5736
European-Non Finnish (NFE)
AF:
0.0000108
AC:
12
AN:
1111752
Other (OTH)
AF:
0.00
AC:
0
AN:
60380
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.471
Heterozygous variant carriers
0
1
3
4
6
7
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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.:
33
Alfa
AF:
0.000111
Hom.:
0
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Bloom syndrome Uncertain:2
Feb 24, 2019
Natera, Inc.
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Dec 23, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces methionine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 1190 of the BLM protein (p.Met1190Thr). This variant is not present in population databases (gnomAD no frequency). 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: 485339). 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 not expected to disrupt BLM protein function with a negative 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:2
Nov 15, 2021
Sema4, Sema4
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:curation

- -

May 31, 2023
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.M1190T variant (also known as c.3569T>C), located in coding exon 18 of the BLM gene, results from a T to C substitution at nucleotide position 3569. The methionine at codon 1190 is replaced by threonine, an amino acid with similar 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.13
BayesDel_addAF
Benign
-0.11
T
BayesDel_noAF
Benign
-0.40
CADD
Benign
22
DANN
Benign
0.88
DEOGEN2
Benign
0.13
T
Eigen
Benign
-0.084
Eigen_PC
Benign
0.14
FATHMM_MKL
Uncertain
0.94
D
LIST_S2
Benign
0.77
T
M_CAP
Benign
0.0079
T
MetaRNN
Benign
0.22
T
MetaSVM
Benign
-1.1
T
MutationAssessor
Benign
1.6
L
PhyloP100
5.1
PrimateAI
Benign
0.46
T
PROVEAN
Benign
-2.1
N
REVEL
Benign
0.064
Sift
Benign
0.33
T
Sift4G
Benign
0.39
T
Polyphen
0.014
B
Vest4
0.23
MutPred
0.49
Gain of sheet (P = 0.0125);
MVP
0.82
MPC
0.16
ClinPred
0.50
D
GERP RS
5.8
Varity_R
0.17
gMVP
0.37

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.14
Details are displayed if max score is > 0.2

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

Publications

Other links and lift over

dbSNP: rs1555424373; hg19: chr15-91347407; API