6-170543726-T-C

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM2 PM5 PP3_Strong

The NM_002793.4(PSMB1):c.308A>G(p.Tyr103Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Y103H) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: PSMB1 NM_002793.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.20

Genes affected

PSMB1 (HGNC:9537): (proteasome 20S subunit beta 1) 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 tightly linked to the TBP (TATA-binding protein) gene in human and in mouse, and is transcribed in the opposite orientation in both species. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr6-170543727-A-G is described in ClinVar as [Pathogenic]. Clinvar id is 1705855.Status of the report is no_assertion_criteria_provided, 0 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.977

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PSMB1	NM_002793.4	c.308A>G	p.Tyr103Cys	missense_variant	4/6	ENST00000262193.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PSMB1	ENST00000262193.7	c.308A>G	p.Tyr103Cys	missense_variant	4/6	1	NM_002793.4	P1
PSMB1	ENST00000462957.1	n.1523A>G		non_coding_transcript_exon_variant	3/5	2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Aug 12, 2021

The c.308A>G (p.Y103C) alteration is located in exon 4 (coding exon 4) of the PSMB1 gene. This alteration results from a A to G substitution at nucleotide position 308, causing the tyrosine (Y) at amino acid position 103 to be replaced by a cysteine (C). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.29	D
BayesDel_noAF	Pathogenic	0.17
Cadd	Pathogenic	31
Dann	Uncertain	1.0
DEOGEN2	Benign	0.41	T
Eigen	Pathogenic	0.86
Eigen_PC	Pathogenic	0.78
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.96	D
M_CAP	Benign	0.043	D
MetaRNN	Pathogenic	0.98	D
MetaSVM	Benign	-0.56	T
MutationAssessor	Pathogenic	3.4	M
MutationTaster	Benign	1.0	D
PrimateAI	Pathogenic	0.91	D
PROVEAN	Pathogenic	-8.7	D
REVEL	Pathogenic	0.66
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.99
MutPred		0.91		Gain of methylation at K104 (P = 0.0214);
MVP		0.56
MPC		1.2
ClinPred		1.0	D
GERP RS		5.1
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.98
gMVP		0.98

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr6-170852814;