7-76302728-G-T

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM1PM2PP3

The NM_001540.5(HSPB1):​c.16G>T​(p.Val6Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000689 in 1,451,308 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 Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V6I) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 6.9e-7 ( 0 hom. )

Consequence

HSPB1
NM_001540.5 missense

Scores

5
11
3

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 3.41

Publications

3 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 5 ACMG points.

PM1
In a chain Heat shock protein beta-1 (size 204) in uniprot entity HSPB1_HUMAN there are 29 pathogenic changes around while only 8 benign (78%) in NM_001540.5
PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.762

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
HSPB1NM_001540.5 linkc.16G>T p.Val6Phe missense_variant Exon 1 of 3 ENST00000248553.7 NP_001531.1 P04792V9HW43

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
HSPB1ENST00000248553.7 linkc.16G>T p.Val6Phe missense_variant Exon 1 of 3 1 NM_001540.5 ENSP00000248553.6 P04792

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD2 exomes
AF:
0.00000423
AC:
1
AN:
236252
AF XY:
0.00000766
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:
0.00000920
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
6.89e-7
AC:
1
AN:
1451308
Hom.:
0
Cov.:
31
AF XY:
0.00000138
AC XY:
1
AN XY:
722342
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33430
American (AMR)
AF:
0.00
AC:
0
AN:
44700
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26114
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39686
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86174
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
44386
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
4796
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1111832
Other (OTH)
AF:
0.00
AC:
0
AN:
60190
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
Cov.:
33
Alfa
AF:
0.0000173
Hom.:
0

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Charcot-Marie-Tooth disease axonal type 2F Uncertain:1
Dec 30, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces valine, which is neutral and non-polar, with phenylalanine, which is neutral and non-polar, at codon 6 of the HSPB1 protein (p.Val6Phe). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This variant has not been reported in the literature in individuals affected with HSPB1-related conditions. 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.42
BayesDel_addAF
Pathogenic
0.16
D
BayesDel_noAF
Uncertain
-0.010
CADD
Pathogenic
28
DANN
Uncertain
0.99
DEOGEN2
Uncertain
0.47
T
Eigen
Uncertain
0.61
Eigen_PC
Uncertain
0.60
FATHMM_MKL
Uncertain
0.93
D
LIST_S2
Uncertain
0.89
D
M_CAP
Pathogenic
0.74
D
MetaRNN
Pathogenic
0.76
D
MetaSVM
Uncertain
0.60
D
MutationAssessor
Benign
1.4
L
PhyloP100
3.4
PrimateAI
Pathogenic
0.80
T
PROVEAN
Benign
-1.9
N
REVEL
Pathogenic
0.69
Sift
Uncertain
0.0030
D
Sift4G
Uncertain
0.011
D
Polyphen
0.99
D
Vest4
0.56
MutPred
0.40
Gain of disorder (P = 0.0453);
MVP
0.97
MPC
1.7
ClinPred
0.93
D
GERP RS
4.9
PromoterAI
0.049
Neutral
Varity_R
0.78
gMVP
0.93
Mutation Taster
=70/30
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: rs1049324; hg19: chr7-75932045; API