chr7-76302914-G-C

Position:

• chr7-76302914-G-C

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 2P and 6B. PM1 BP4_Moderate BS2

The NM_001540.5(HSPB1):​c.202G>C​(p.Val68Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000181 in 1,545,538 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. V68V) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.000026 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000017 (0 hom.)
• Consequence: HSPB1 NM_001540.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.683

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]

ACMG classification

Verdict is Likely_benign. Variant got -4 ACMG points.

• PM1: In a chain Heat shock protein beta-1 (size 204) in uniprot entity HSPB1_HUMAN there are 63 pathogenic changes around while only 11 benign (85%) in NM_001540.5
• BP4: Computational evidence support a benign effect (MetaRNN=0.12383461).
• BS2: High AC in GnomAdExome4 at 24 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
HSPB1	NM_001540.5	c.202G>C	p.Val68Leu	missense_variant	1/3	ENST00000248553.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
HSPB1	ENST00000248553.7	c.202G>C	p.Val68Leu	missense_variant	1/3	1	NM_001540.5	P1

Frequencies

GnomAD3 genomes AF: 0.0000263 AC: 4 AN: 152048 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000131

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: 0.000478

GnomAD3 exomes AF: 0.00000684 AC: 1 AN: 146276 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 80430

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 SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.000233

GnomAD4 exome AF: 0.0000172 AC: 24 AN: 1393490 Hom.: 0 Cov.: 31 AF XY: 0.0000102 AC XY: 7 AN XY: 688608

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

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: 0.0000222

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000263 AC: 4 AN: 152048 Hom.: 0 Cov.: 33 AF XY: 0.0000404 AC XY: 3 AN XY: 74262

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.000131

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.000478

Bravo AF: 0.0000227

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Charcot-Marie-Tooth disease axonal type 2F Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Mar 18, 2022

Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The leucine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect 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. ClinVar contains an entry for this variant (Variation ID: 410716). This variant has not been reported in the literature in individuals affected with HSPB1-related conditions. This variant is present in population databases (no rsID available, gnomAD 0.002%). This sequence change replaces valine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 68 of the HSPB1 protein (p.Val68Leu). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.087
BayesDel_addAF	Benign	-0.17	T
BayesDel_noAF	Benign	-0.46
CADD	Benign	6.2
DANN	Benign	0.53
DEOGEN2	Benign	0.28	T
Eigen	Benign	-1.1
Eigen_PC	Benign	-1.1
FATHMM_MKL	Benign	0.18	N
LIST_S2	Benign	0.50	T
M_CAP	Pathogenic	0.56	D
MetaRNN	Benign	0.12	T
MetaSVM	Benign	-0.74	T
MutationAssessor	Benign	0.0	N
MutationTaster	Benign	1.0	N
PrimateAI	Uncertain	0.74	T
PROVEAN	Benign	0.34	N
REVEL	Benign	0.14
Sift	Benign	0.65	T
Sift4G	Benign	0.76	T
Polyphen		0.0	B
Vest4		0.036
MutPred		0.30		Gain of helix (P = 0.062);
MVP		0.72
MPC		0.55
ClinPred		0.023	T
GERP RS		1.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.072
gMVP		0.53

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

LitVar

Other links and lift over

dbSNP: rs757158514; hg19: chr7-75932231;