rs375972376

Variant names:

• chr7-76303977-C-G
• rs375972376
• NM_001540.5:c.429-7C>G

Your query was ambiguous. Multiple possible variants found:

• chr7-76303977-C-G
• chr7-76303977-C-T

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 1P and 4B. PP3 BS2

The NM_001540.5(HSPB1):​c.429-7C>G variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000753 in 1,461,266 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000075 (1 hom.)
• Consequence: HSPB1 NM_001540.5 splice_region, intron
• Scores: Splicing: ADA: 0.9994
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -2.25
• Publications: 1 publications found

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

ACMG classification

Our verdict: Likely_benign. The variant received -3 ACMG points.

• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• BS2: High AC in GnomAdExome4 at 11 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
HSPB1	NM_001540.5	c.429-7C>G		splice_region_variant, intron_variant	Intron 2 of 2	ENST00000248553.7	NP_001531.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
HSPB1	ENST00000248553.7	c.429-7C>G		splice_region_variant, intron_variant	Intron 2 of 2	1	NM_001540.5	ENSP00000248553.6

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000801 AC: 2 AN: 249550 AF XY: 0.0000148

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: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000753 AC: 11 AN: 1461266 Hom.: 1 Cov.: 33 AF XY: 0.0000124 AC XY: 9 AN XY: 726946

African (AFR) AF: 0.00 AC: 0 AN: 33472

American (AMR) AF: 0.00 AC: 0 AN: 44708

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26132

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.000128 AC: 11 AN: 86238

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52976

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111890

Other (OTH) AF: 0.00 AC: 0 AN: 60384

GnomAD4 genome Cov.: 32

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

Jul 25, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. This variant has not been reported in the literature in individuals affected with HSPB1-related conditions. This variant is present in population databases (rs375972376, gnomAD 0.007%). This sequence change falls in intron 2 of the HSPB1 gene. It does not directly change the encoded amino acid sequence of the HSPB1 protein. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.74
CADD	Benign	19
DANN	Benign	0.74
PhyloP100		-2.3
PromoterAI		-0.024	Neutral

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.91
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_AG_spliceai		1.0		Position offset: 1
DS_AL_spliceai		0.96		Position offset: 7

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs375972376; hg19: chr7-75933294;