chr3-136250377-T-G

Variant names:

• chr3-136250377-T-G
• rs398123462
• NM_000532.5:c.2T>G

Variant summary

Our verdict is Pathogenic. The variant received 14 ACMG points: 14P and 0B. PVS1 PS1_Moderate PM2 PP5_Moderate

The NM_000532.5(PCCB):​c.2T>G​(p.Met1?) variant causes a start lost change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000728 in 1,374,114 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 7.3e-7 (0 hom.)
• Consequence: PCCB NM_000532.5 start_lost
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 2.47
• Publications: 0 publications found

Genes affected

PCCB (HGNC:8654): (propionyl-CoA carboxylase subunit beta) The protein encoded by this gene is a subunit of the propionyl-CoA carboxylase (PCC) enzyme, which is involved in the catabolism of propionyl-CoA. PCC is a mitochondrial enzyme that probably acts as a dodecamer of six alpha subunits and six beta subunits. This gene encodes the beta subunit of PCC. Defects in this gene are a cause of propionic acidemia type II (PA-2). Multiple transcript variants encoding different isoforms have been found for this gene.[provided by RefSeq, May 2010]

PCCB Gene-Disease associations (from GenCC):

• propionic acidemia

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), G2P, ClinGen, Myriad Women’s Health, Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 14 ACMG points.

• PVS1: Start lost variant, next in-frame start position is after 31 pathogenic variants. Next in-frame start position is after 84 codons. Genomic position: 136255922. Lost 0.154 part of the original CDS.
• PS1: Another start lost variant in NM_000532.5 (PCCB) was described as [Likely_pathogenic] in ClinVar as 93230
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 3-136250377-T-G is Pathogenic according to our data. Variant chr3-136250377-T-G is described in ClinVar as [Pathogenic]. Clinvar id is 2745320.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PCCB	NM_000532.5	c.2T>G	p.Met1?	start_lost	Exon 1 of 15	ENST00000251654.9	NP_000523.2
PCCB	NM_001178014.2	c.2T>G	p.Met1?	start_lost	Exon 1 of 16		NP_001171485.1
PCCB	XM_011512873.2	c.2T>G	p.Met1?	start_lost	Exon 1 of 11		XP_011511175.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PCCB	ENST00000251654.9	c.2T>G	p.Met1?	start_lost	Exon 1 of 15	1	NM_000532.5	ENSP00000251654.4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 7.28e-7 AC: 1 AN: 1374114 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 674266

African (AFR) AF: 0.00 AC: 0 AN: 31108

American (AMR) AF: 0.00 AC: 0 AN: 34416

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 22432

East Asian (EAS) AF: 0.00 AC: 0 AN: 36556

South Asian (SAS) AF: 0.00 AC: 0 AN: 75010

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 48126

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5192

European-Non Finnish (NFE) AF: 9.39e-7 AC: 1 AN: 1064700

Other (OTH) AF: 0.00 AC: 0 AN: 56574

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Propionic acidemia Pathogenic:1

Jul 19, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change affects the initiator methionine of the PCCB mRNA. The next in-frame methionine is located at codon 84. This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with PCCB-related conditions. This variant disrupts a region of the PCCB protein in which other variant(s) (p.His59Gln) have been determined to be pathogenic (Invitae). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.62
CADD	Benign	23
DANN	Benign	0.94
DEOGEN2	Benign	0.30	T;.;.;T;T;T;.;.;.;.;T
Eigen	Uncertain	0.28
Eigen_PC	Uncertain	0.26
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Uncertain	0.90	D;D;D;D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.91	D
MetaRNN	Pathogenic	0.98	D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.0	D
PhyloP100		2.5
PROVEAN	Benign	-0.38	N;N;N;N;N;N;N;N;N;N;N
REVEL	Pathogenic	0.72
Sift	Uncertain	0.0020	D;D;D;D;D;D;D;D;D;D;D
Sift4G	Uncertain	0.0030	D;D;D;D;D;D;D;D;D;D;D
Polyphen		0.86	P;.;.;.;.;.;.;P;.;.;.
Vest4		0.82
MutPred		0.91		Gain of methylation at M1 (P = 7e-04);Gain of methylation at M1 (P = 7e-04);Gain of methylation at M1 (P = 7e-04);Gain of methylation at M1 (P = 7e-04);Gain of methylation at M1 (P = 7e-04);Gain of methylation at M1 (P = 7e-04);Gain of methylation at M1 (P = 7e-04);Gain of methylation at M1 (P = 7e-04);Gain of methylation at M1 (P = 7e-04);Gain of methylation at M1 (P = 7e-04);Gain of methylation at M1 (P = 7e-04);
MVP		0.98
ClinPred		0.99	D
GERP RS		5.0
PromoterAI		-0.91	Under-expression
Varity_R		0.96
gMVP		0.83
Mutation Taster		=1/199	disease causing

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: rs398123462; hg19: chr3-135969219;