rs771232749

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM1PM5

The NM_001540.5(HSPB1):​c.451A>C​(p.Thr151Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000105 in 1,613,446 control chromosomes in the GnomAD database, with no homozygous occurrence. There is a variant allele frequency bias in the population database for this variant (GnomAdExome4), which may indicate mosaicism or somatic mutations in the reference population data. 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. T151I) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000010 ( 0 hom. )

Consequence

HSPB1
NM_001540.5 missense

Scores

2
10
7

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 2.45

Publications

1 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: Uncertain_significance. The variant received 4 ACMG points.

PM1
In a domain sHSP (size 108) in uniprot entity HSPB1_HUMAN there are 22 pathogenic changes around while only 2 benign (92%) in NM_001540.5
PM5
Other missense variant is known to change same aminoacid residue: Variant chr7-76304007-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 7480.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.451A>C p.Thr151Pro missense_variant Exon 3 of 3 ENST00000248553.7 NP_001531.1 P04792V9HW43

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
HSPB1ENST00000248553.7 linkc.451A>C p.Thr151Pro missense_variant Exon 3 of 3 1 NM_001540.5 ENSP00000248553.6 P04792

Frequencies

GnomAD3 genomes
AF:
0.0000132
AC:
2
AN:
151878
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
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:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000400
AC:
1
AN:
249748
AF XY:
0.00000738
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:
0.00000888
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000103
AC:
15
AN:
1461568
Hom.:
0
Cov.:
33
AF XY:
0.0000110
AC XY:
8
AN XY:
727084
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
33478
American (AMR)
AF:
0.00
AC:
0
AN:
44712
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39696
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86246
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53164
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5758
European-Non Finnish (NFE)
AF:
0.0000135
AC:
15
AN:
1111998
Other (OTH)
AF:
0.00
AC:
0
AN:
60380
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.395
Heterozygous variant carriers
0
1
2
4
5
6
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
AF:
0.0000132
AC:
2
AN:
151878
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74150
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41314
American (AMR)
AF:
0.00
AC:
0
AN:
15252
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5180
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4812
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10590
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
67956
Other (OTH)
AF:
0.00
AC:
0
AN:
2080
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.450
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:
0.0000413
Hom.:
0
Bravo
AF:
0.00000378
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Charcot-Marie-Tooth disease axonal type 2F Uncertain:1
Feb 24, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces threonine, which is neutral and polar, with proline, which is neutral and non-polar, at codon 151 of the HSPB1 protein (p.Thr151Pro). This variant is present in population databases (no rsID available, gnomAD 0.002%). This missense change has been observed in individual(s) with amyotrophic lateral sclerosis (PMID: 33509756). ClinVar contains an entry for this variant (Variation ID: 465275). 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) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on HSPB1 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:1
Jul 01, 2022
CeGaT Center for Human Genetics Tuebingen
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

HSPB1: PM1, PM2 -

Neuronopathy, distal hereditary motor, type 2B Uncertain:1
Mar 04, 2025
Institute of Human Genetics, University of Leipzig Medical Center
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Criteria applied: PM5,PS4_SUP,PM1_SUP,PM2_SUP -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.49
BayesDel_addAF
Uncertain
0.12
D
BayesDel_noAF
Uncertain
-0.060
CADD
Benign
20
DANN
Uncertain
0.98
DEOGEN2
Pathogenic
0.86
D
Eigen
Benign
0.0032
Eigen_PC
Benign
-0.076
FATHMM_MKL
Uncertain
0.77
D
LIST_S2
Benign
0.23
T
M_CAP
Pathogenic
0.40
D
MetaRNN
Uncertain
0.62
D
MetaSVM
Uncertain
0.26
D
MutationAssessor
Uncertain
2.6
M
PhyloP100
2.4
PrimateAI
Benign
0.44
T
PROVEAN
Uncertain
-2.7
D
REVEL
Uncertain
0.56
Sift
Benign
0.25
T
Sift4G
Benign
0.26
T
Polyphen
0.96
D
Vest4
0.34
MutPred
0.36
Gain of catalytic residue at P150 (P = 0.0133);
MVP
0.98
MPC
1.6
ClinPred
0.88
D
GERP RS
2.3
PromoterAI
-0.045
Neutral
Varity_R
0.96
gMVP
0.69
Mutation Taster
=65/35
polymorphism

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: rs771232749; hg19: chr7-75933323; API