7-76304114-TCG-CTA

Variant names:

• chr7-76304114-TCG-CTA
• NM_001540.5:c.559_561delTCGinsCTA
• HSPB1 p.Ser187Leu

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PS1_Moderate PM1

The NM_001540.5(HSPB1):​c.559_561delTCGinsCTA​(p.Ser187Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. It is difficult to determine the true allele frequency of this variant because it is of type MNV, and the frequency of such variant types in population databases may be underestimated and unreliable. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another nucleotide change resulting in the same amino acid substitution has been previously reported as Likely pathogenic in ClinVar.

• Frequency: Genomes: not found (cov: 32)
• Consequence: HSPB1 NM_001540.5 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 2.13
• Publications: 0 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: Illumina, Labcorp Genetics (formerly Invitae), ClinGen, Orphanet
• 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: Uncertain_significance. The variant received 4 ACMG points.

• PS1: Transcript NM_001540.5 (HSPB1) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in ClinVar.
• PM1: In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 17 uncertain in NM_001540.5

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001540.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	HSPB1	NM_001540.5	MANE Select	c.559_561delTCGinsCTA	p.Ser187Leu	missense	N/A	NP_001531.1	P04792

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	HSPB1	ENST00000248553.7	TSL:1 MANE Select	c.559_561delTCGinsCTA	p.Ser187Leu	missense	N/A	ENSP00000248553.6	P04792
	HSPB1	ENST00000429938.1	TSL:1	c.55_57delTCGinsCTA	p.Ser19Leu	missense	N/A	ENSP00000405285.1	C9J3N8
	HSPB1	ENST00000447574.1	TSL:1	n.1309_1311delTCGinsCTA		non_coding_transcript_exon	Exon 2 of 2

Frequencies

GnomAD3 genomes Cov.: 32

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		2.1

Splicing

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

hg19: chr7-75933431;