12-119193779-T-C

Position:

chr12-119193779-T-C

Variant summary

Our verdict is Likely benign. Variant got -6 ACMG points: 0P and 6B. BP4_ModerateBS2

The ENST00000281938.7(HSPB8):c.512T>C(p.Val171Ala) variant causes a missense change. The variant allele was found at a frequency of 0.0000192 in 1,613,998 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 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. V171I) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000085 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000012 ( 0 hom. )

Consequence

HSPB8
ENST00000281938.7 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 4.82

Variant links:

Genes affected

HSPB8 (HGNC:30171): (heat shock protein family B (small) member 8) The protein encoded by this gene belongs to the superfamily of small heat-shock proteins containing a conservative alpha-crystallin domain at the C-terminal part of the molecule. The expression of this gene in induced by estrogen in estrogen receptor-positive breast cancer cells, and this protein also functions as a chaperone in association with Bag3, a stimulator of macroautophagy. Thus, this gene appears to be involved in regulation of cell proliferation, apoptosis, and carcinogenesis, and mutations in this gene have been associated with different neuromuscular diseases, including Charcot-Marie-Tooth disease. [provided by RefSeq, Jul 2008]

HSPB8 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -6 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.12949735).

BS2

High AC in GnomAd4 at 13 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
HSPB8	NM_014365.3 linkuse as main transcript	c.512T>C	p.Val171Ala	missense_variant	3/3	ENST00000281938.7	NP_055180.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
HSPB8	ENST00000281938.7 linkuse as main transcript	c.512T>C	p.Val171Ala	missense_variant	3/3	1	NM_014365.3	ENSP00000281938	P1

Frequencies

GnomAD3 genomes

AF:

0.0000854

AC:

AN:

152144

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000786

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:

0.00

Gnomad OTH

AF:

0.000478

GnomAD3 exomes

AF:

0.00000398

AC:

AN:

251494

Hom.:

AF XY:

0.00000736

AC XY:

AN XY:

135920

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000289

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:

0.00

GnomAD4 exome

AF:

0.0000123

AC:

AN:

1461854

Hom.:

Cov.:

AF XY:

0.00000825

AC XY:

AN XY:

727228

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.000246

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:

0.00

Gnomad4 OTH exome

AF:

0.000116

GnomAD4 genome

AF:

0.0000854

AC:

AN:

152144

Hom.:

Cov.:

AF XY:

0.0000807

AC XY:

AN XY:

74328

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.000786

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.000478

Bravo

AF:

0.000257

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Nov 10, 2016

- -

Inborn genetic diseases

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 19, 2023

The c.512T>C (p.V171A) alteration is located in exon 3 (coding exon 3) of the HSPB8 gene. This alteration results from a T to C substitution at nucleotide position 512, causing the valine (V) at amino acid position 171 to be replaced by an alanine (A). The alteration is rare in population databases: _x000D_ _x000D_ Based on data from the Genome Aggregation Database (gnomAD), the c.512T>C alteration was observed in <0.001% (1/251,494) of total alleles studied. The altered amino acid is not conserved throughout evolution:_x000D_ _x000D_ The p.V171 amino acid is not conserved in available vertebrate species. The alteration is predicted tolerated by in silico modeling:_x000D_ _x000D_ The p.V171A alteration is predicted to be tolerated by in silico analysis. Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Charcot-Marie-Tooth disease axonal type 2L

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jun 29, 2023

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. 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. ClinVar contains an entry for this variant (Variation ID: 240907). This variant has not been reported in the literature in individuals affected with HSPB8-related conditions. This variant is present in population databases (no rsID available, gnomAD 0.006%). This sequence change replaces valine, which is neutral and non-polar, with alanine, which is neutral and non-polar, at codon 171 of the HSPB8 protein (p.Val171Ala). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.34

BayesDel_addAF

Benign

-0.067

BayesDel_noAF

Benign

-0.16

CADD

Benign

DANN

Benign

0.96

DEOGEN2

Benign

0.35

Eigen

Benign

-0.29

Eigen_PC

Benign

-0.18

FATHMM_MKL

Benign

0.75

LIST_S2

Benign

0.83

M_CAP

Benign

0.039

MetaRNN

Benign

0.13

MetaSVM

Uncertain

-0.26

MutationAssessor

Benign

1.2

MutationTaster

Benign

0.77

PrimateAI

Uncertain

0.53

PROVEAN

Benign

-0.45

REVEL

Benign

0.20

Sift

Benign

0.24

Sift4G

Benign

0.82

Polyphen

0.12

Vest4

0.19

MutPred

0.42

Gain of catalytic residue at P172 (P = 2e-04);

MVP

0.94

MPC

0.30

ClinPred

0.23

GERP RS

3.3

Varity_R

0.035

gMVP

0.32

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.020

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