3-136326839-G-T

Variant names:

• chr3-136326839-G-T
• rs142982097
• NM_000532.5:c.1127G>T

Variant summary

Our verdict is Pathogenic. The variant received 17 ACMG points: 17P and 0B. PM2 PM5 PP2 PP3_Strong PP5_Very_Strong

The NM_000532.5(PCCB):​c.1127G>T​(p.Arg376Leu) 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. 13/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R376H) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: PCCB NM_000532.5 missense
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:2 U:1
• Conservation: PhyloP100: 9.27
• Publications: 5 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 17 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr3-136326838-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 1451151.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 61 curated pathogenic missense variants (we use a threshold of 10). The gene has 6 curated benign missense variants. Gene score misZ: -0.86701 (below the threshold of 3.09). Trascript score misZ: -0.97134 (below the threshold of 3.09). GenCC associations: The gene is linked to propionic acidemia.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.973
• PP5: Variant 3-136326839-G-T is Pathogenic according to our data. Variant chr3-136326839-G-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 558333.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PCCB	NM_000532.5	c.1127G>T	p.Arg376Leu	missense_variant	Exon 11 of 15	ENST00000251654.9	NP_000523.2
PCCB	NM_001178014.2	c.1187G>T	p.Arg396Leu	missense_variant	Exon 12 of 16		NP_001171485.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PCCB	ENST00000251654.9	c.1127G>T	p.Arg376Leu	missense_variant	Exon 11 of 15	1	NM_000532.5	ENSP00000251654.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2 Uncertain:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Propionic acidemia Pathogenic:2 Uncertain:1

May 14, 2018

Counsyl

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

Jun 09, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with leucine, which is neutral and non-polar, at codon 376 of the PCCB protein (p.Arg376Leu). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with Propionic Acidemia (PMID: 22033733). ClinVar contains an entry for this variant (Variation ID: 558333). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt PCCB protein function. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. This variant disrupts the p.Arg376 amino acid residue in PCCB. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 19342984, 27900673). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. -

Jun 09, 2025

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: PCCB c.1127G>T (p.Arg376Leu) results in a non-conservative amino acid change in the encoded protein sequence. Algorithms developed to predict the effect of missense changes on protein structure and function all suggest that this variant is likely to be disruptive. The variant was absent in 251386 control chromosomes (gnomAD). c.1127G>T has been observed in individuals affected with Propionic Acidemia (Kraus_2012, Liu_2022). These data indicate that the variant is likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 22033733, 34297429, 35331292). ClinVar contains an entry for this variant (Variation ID: 558333). Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.95
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.60
CADD	Pathogenic	32
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.95	D;.;.;D;D;D;.;.;.
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	1.0	D;D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.54	D
MetaRNN	Pathogenic	0.97	D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	4.7	H;.;.;.;.;.;.;.;.
PhyloP100		9.3
PrimateAI	Pathogenic	0.90	D
PROVEAN	Pathogenic	-6.5	D;D;D;D;D;D;D;D;D
REVEL	Pathogenic	0.98
Sift	Pathogenic	0.0	D;D;D;D;D;D;D;D;D
Sift4G	Pathogenic	0.0	D;D;D;D;D;D;D;D;D
Polyphen		1.0	D;.;.;.;.;.;.;D;.
Vest4		0.96
MutPred		0.87		Loss of catalytic residue at R376 (P = 0.0591);.;.;.;.;.;.;Loss of catalytic residue at R376 (P = 0.0591);.;
MVP		0.98
MPC		0.57
ClinPred		1.0	D
GERP RS		5.0
Varity_R		0.99
gMVP		0.90
Mutation Taster		=0/100	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.050		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: rs142982097; hg19: chr3-136045681;