NM_006308.3:c.355A>C

Variant names:

• chr5-54456144-A-C
• rs41270303
• NM_006308.3:c.355A>C

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM2 BP4

The NM_006308.3(HSPB3):​c.355A>C​(p.Lys119Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,186 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/22 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. K119E) has been classified as Likely benign.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: HSPB3 NM_006308.3 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 3.11
• Publications: 3 publications found

Genes affected

HSPB3 (HGNC:5248): (heat shock protein family B (small) member 3) This gene encodes a muscle-specific small heat shock protein. A mutation in this gene is the cause of autosomal dominant distal hereditary motor neuropathy type 2C.[provided by RefSeq, Sep 2010]

HSPB3 Gene-Disease associations (from GenCC):

• distal hereditary motor neuropathy type 2

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• neuronopathy, distal hereditary motor, type 2C

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.41890758).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
HSPB3	NM_006308.3	c.355A>C	p.Lys119Gln	missense_variant	Exon 1 of 1	ENST00000302005.3	NP_006299.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
HSPB3	ENST00000302005.3	c.355A>C	p.Lys119Gln	missense_variant	Exon 1 of 1	6	NM_006308.3	ENSP00000303394.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152186 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

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: 0.00

GnomAD4 exome Cov.: 53

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152186 Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1 AN XY: 74354

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 41448

American (AMR) AF: 0.00 AC: 0 AN: 15268

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5190

South Asian (SAS) AF: 0.00 AC: 0 AN: 4832

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10624

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68030

Other (OTH) AF: 0.00 AC: 0 AN: 2094

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.00 Hom.: 1

Bravo AF: 0.00000378

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.10
BayesDel_addAF	Uncertain	0.029	T
BayesDel_noAF	Benign	-0.20
CADD	Benign	19
DANN	Benign	0.92
DEOGEN2	Benign	0.38	T
Eigen	Benign	-0.18
Eigen_PC	Benign	-0.072
FATHMM_MKL	Uncertain	0.79	D
LIST_S2	Benign	0.78	T
M_CAP	Benign	0.058	D
MetaRNN	Benign	0.42	T
MetaSVM	Uncertain	-0.10	T
MutationAssessor	Benign	0.41	N
PhyloP100		3.1
PrimateAI	Uncertain	0.52	T
PROVEAN	Benign	-1.1	N
REVEL	Uncertain	0.29
Sift	Benign	0.47	T
Sift4G	Benign	0.49	T
Polyphen		0.64	P
Vest4		0.19
MutPred		0.34		Loss of ubiquitination at K119 (P = 0.0326);
MVP		0.86
MPC		0.14
ClinPred		0.54	D
GERP RS		4.5
PromoterAI		-0.056	Neutral
Varity_R		0.24
gMVP		0.25
Mutation Taster		=90/10	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs41270303; hg19: chr5-53751974;