rs863225023

Variant summary

Our verdict is Pathogenic. The variant received 14 ACMG points: 14P and 0B. PVS1_StrongPM2PP5_Very_Strong

The NM_001540.5(HSPB1):​c.523C>T​(p.Gln175*) variant causes a stop gained change. The variant allele was found at a frequency of 0.0000131 in 152,188 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0 ( 0 hom. )
Failed GnomAD Quality Control

Consequence

HSPB1
NM_001540.5 stop_gained

Scores

4
4
6

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3U:1

Conservation

PhyloP100: 3.67

Publications

6 publications found
Variant links:
Genes affected
HSPB1 (HGNC:5246): (heat shock protein family B (small) member 1) This gene encodes a member of the small heat shock protein (HSP20) family of proteins. In response to environmental stress, the encoded protein translocates from the cytoplasm to the nucleus and functions as a molecular chaperone that promotes the correct folding of other proteins. This protein plays an important role in the differentiation of a wide variety of cell types. Expression of this gene is correlated with poor clinical outcome in multiple human cancers, and the encoded protein may promote cancer cell proliferation and metastasis, while protecting cancer cells from apoptosis. Mutations in this gene have been identified in human patients with Charcot-Marie-Tooth disease and distal hereditary motor neuropathy. [provided by RefSeq, Aug 2017]
HSPB1 Gene-Disease associations (from GenCC):
  • Charcot-Marie-Tooth disease axonal type 2F
    Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, ClinGen, Illumina, Labcorp Genetics (formerly Invitae)
  • neuronopathy, distal hereditary motor, type 2B
    Inheritance: AD Classification: MODERATE Submitted by: Ambry Genetics
  • distal hereditary motor neuropathy type 2
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 14 ACMG points.

PVS1
Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 10 pathogenic variants in the truncated region.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 7-76304078-C-T is Pathogenic according to our data. Variant chr7-76304078-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 217231.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
HSPB1NM_001540.5 linkc.523C>T p.Gln175* stop_gained Exon 3 of 3 ENST00000248553.7 NP_001531.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
HSPB1ENST00000248553.7 linkc.523C>T p.Gln175* stop_gained Exon 3 of 3 1 NM_001540.5 ENSP00000248553.6

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152188
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
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
GnomAD2 exomes
AF:
0.00000403
AC:
1
AN:
248140
AF XY:
0.00000742
show subpopulations
Gnomad AFR exome
AF:
0.0000631
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:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
Data not reliable, filtered out with message: AC0
AF:
0.00
AC:
0
AN:
1461490
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
727038
African (AFR)
AF:
0.00
AC:
0
AN:
33468
American (AMR)
AF:
0.00
AC:
0
AN:
44698
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26130
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39686
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86212
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53300
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5730
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111910
Other (OTH)
AF:
0.00
AC:
0
AN:
60356
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152188
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74346
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41446
American (AMR)
AF:
0.00
AC:
0
AN:
15274
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5192
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10622
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68032
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.550
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome 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
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.0000113

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:3Uncertain:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:2
Jul 25, 2018
GeneDx
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

A variant that is likely pathogenic has been identified in the HSPB1 gene. The Q175X nonsense variant has been previously reported to segregate with CMT2 in six affected family members (Rossor et al., 2012). This variant is predicted to cause loss of normal protein function through protein truncation as the last 31 amino acid residues are lost. The Q175X variant is not observed at a significant frequency in large population cohorts (Lek et al., 2016). Therefore, the Q175X variant is likely pathogenic; however, the possibility that it is benign cannot be excluded.

Sep 26, 2022
Athena Diagnostics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant creates a premature stop codon resulting in a truncated HSPB1. Similar truncating variants in this gene have been reported in cases of axonal Charcot-Marie-Tooth disease (PMID: 32334137, 26675522). The frequency of this variant in the general population is consistent with pathogenicity (http://gnomad.broadinstitute.org). This variant has been identified in multiple unrelated individuals with motor neuropathies and appears to segregate with axonal Charcot-Marie-Tooth disease in at least one family.

Charcot-Marie-Tooth disease axonal type 2F Pathogenic:1
Dec 18, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Gln175*) in the HSPB1 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 31 amino acid(s) of the HSPB1 protein. This variant is present in population databases (no rsID available, gnomAD 0.007%). This premature translational stop signal has been observed in individuals with autosomal dominant Charcot-Marie-Tooth disease (PMID: 22734906, 28144995). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 217231). This variant is located in a region of the HSPB1 protein where a significant number of HSPB1 nonsense and frameshift mutations have been reported in association with autosomal dominant HSPB1-related neuropathies (PMID: 22734906, 28144995, 33686258). For these reasons, this variant has been classified as Pathogenic.

Charcot-Marie-Tooth disease Uncertain:1
Aug 14, 2019
Genesis Genome Database
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:research

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.48
D
BayesDel_noAF
Pathogenic
0.57
CADD
Pathogenic
37
DANN
Uncertain
0.99
DEOGEN2
Benign
0.0
.;.
Eigen
Uncertain
0.64
Eigen_PC
Uncertain
0.44
FATHMM_MKL
Uncertain
0.81
D
LIST_S2
Benign
0.0
.;.
MetaRNN
Benign
0.0
.;.
MutationAssessor
Benign
0.0
.;.
PhyloP100
3.7
PROVEAN
Benign
0.0
.;.
REVEL
Benign
0.0
Sift
Pathogenic
0.0
.;.
Sift4G
Pathogenic
0.0
.;.
Vest4
0.89
GERP RS
4.7
Mutation Taster
=3/197
disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs863225023; hg19: chr7-75933395; API