chr6-32843017-T-C

Variant names:

• chr6-32843017-T-C
• rs17220206
• NM_148919.4:c.220A>G

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_148919.4(PSMB8):​c.220A>G​(p.Thr74Ala) variant causes a missense change. The variant allele was found at a frequency of 0.00000137 in 1,460,786 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic 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. T74S) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: PSMB8 NM_148919.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 7.20
• Publications: 9 publications found

Genes affected

PSMB8 (HGNC:9545): (proteasome 20S subunit beta 8) The proteasome is a multicatalytic proteinase complex with a highly ordered ring-shaped 20S core structure. The core structure is composed of 4 rings of 28 non-identical subunits; 2 rings are composed of 7 alpha subunits and 2 rings are composed of 7 beta subunits. Proteasomes are distributed throughout eukaryotic cells at a high concentration and cleave peptides in an ATP/ubiquitin-dependent process in a non-lysosomal pathway. An essential function of a modified proteasome, the immunoproteasome, is the processing of class I MHC peptides. This gene encodes a member of the proteasome B-type family, also known as the T1B family, that is a 20S core beta subunit. This gene is located in the class II region of the MHC (major histocompatibility complex). Expression of this gene is induced by gamma interferon and this gene product replaces catalytic subunit 3 (proteasome beta 5 subunit) in the immunoproteasome. Proteolytic processing is required to generate a mature subunit. Two alternative transcripts encoding two isoforms have been identified; both isoforms are processed to yield the same mature subunit. [provided by RefSeq, Jul 2008]

PSMB8 Gene-Disease associations (from GenCC):

• proteasome-associated autoinflammatory syndrome 1

  Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Ambry Genetics, G2P, Labcorp Genetics (formerly Invitae)
• proteosome-associated autoinflammatory syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.977

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_148919.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PSMB8	NM_148919.4	MANE Select	c.220A>G	p.Thr74Ala	missense	Exon 2 of 6	NP_683720.2
	PSMB8	NM_004159.5		c.208A>G	p.Thr70Ala	missense	Exon 2 of 6	NP_004150.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PSMB8	ENST00000374882.8	TSL:1 MANE Select	c.220A>G	p.Thr74Ala	missense	Exon 2 of 6	ENSP00000364016.4
	PSMB8	ENST00000374881.3	TSL:1	c.208A>G	p.Thr70Ala	missense	Exon 2 of 6	ENSP00000364015.2
	PSMB8	ENST00000395339.7	TSL:3	c.220A>G	p.Thr74Ala	missense	Exon 2 of 6	ENSP00000378748.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000405 AC: 1 AN: 246864 AF XY: 0.00

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: 0.00000902

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1460786 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 726708

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

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

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52324

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1112010

Other (OTH) AF: 0.00 AC: 0 AN: 60386

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000835 AC: 1

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.68
BayesDel_addAF	Pathogenic	0.35	D
BayesDel_noAF	Pathogenic	0.27
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Benign	0.26	T
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.95
FATHMM_MKL	Pathogenic	0.98	D
M_CAP	Uncertain	0.27	D
MetaRNN	Pathogenic	0.98	D
MetaSVM	Uncertain	0.45	D
MutationAssessor	Pathogenic	4.1	H
PhyloP100		7.2
PrimateAI	Uncertain	0.61	T
PROVEAN	Pathogenic	-4.4	D
REVEL	Uncertain	0.61
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.92
MutPred		0.88		Loss of glycosylation at T74 (P = 0.0546)
MVP		0.92
MPC		1.5
ClinPred		1.0	D
GERP RS		5.9
Varity_R		0.68
gMVP		0.92
Mutation Taster		=18/82	disease causing

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

Other links and lift over

dbSNP: rs17220206; hg19: chr6-32810794;