3-136326881-C-T

Variant names:

• chr3-136326881-C-T
• rs201880353
• NM_000532.5:c.1169C>T

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM1 PM2 PP3

The NM_000532.5(PCCB):​c.1169C>T​(p.Thr390Ile) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000336 in 1,459,820 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.000034 (1 hom.)
• Consequence: PCCB NM_000532.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 7.31

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 5 ACMG points.

• PM1: In a domain CoA carboxyltransferase C-terminal (size 239) in uniprot entity PCCB_HUMAN there are 29 pathogenic changes around while only 1 benign (97%) in NM_000532.5
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.744

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PCCB	NM_000532.5	c.1169C>T	p.Thr390Ile	missense_variant	Exon 11 of 15	ENST00000251654.9	NP_000523.2
PCCB	NM_001178014.2	c.1229C>T	p.Thr410Ile	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.1169C>T	p.Thr390Ile	missense_variant	Exon 11 of 15	1	NM_000532.5	ENSP00000251654.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.000175 AC: 44 AN: 251410 Hom.: 1 AF XY: 0.000125 AC XY: 17 AN XY: 135880

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00127

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000336 AC: 49 AN: 1459820 Hom.: 1 Cov.: 30 AF XY: 0.0000275 AC XY: 20 AN XY: 726420

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00107

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 32

Bravo AF: 0.0000793

ExAC AF: 0.0000988 AC: 12

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Propionic acidemia Uncertain:2

Oct 24, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces threonine, which is neutral and polar, with isoleucine, which is neutral and non-polar, at codon 390 of the PCCB protein (p.Thr390Ile). This variant is present in population databases (rs201880353, gnomAD 0.1%). This variant has not been reported in the literature in individuals affected with PCCB-related conditions. ClinVar contains an entry for this variant (Variation ID: 496027). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Feb 21, 2020

Natera, Inc.

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

not provided Uncertain:1

Aug 09, 2016

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

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant Summary: The variant of interest causes a missense change involving a conserved nucleotide with 4/4 in silico programs predicting a "deleterious" outcome (SNPs&GO not captured here due to low reliability index), although these predictions have yet to be functionally assessed. The variant of interest has been observed in a large, broad control population, ExAC with an allele frequency of 12/121394 chromosomes (1/10116), predominantly in the Latino cohort with an allele frequency of 12/11578 (1/965), which does not exceed the maximum expected allele frequency for a pathogenic PCCB variant of 1/400. The variant of interest has not been reported in affected individuals via publications and/or reputable databases/clinical laboratories. Therefore, taking all lines of available evidence into consideration, the variant of interest is classified as a "variant of uncertain significance (VUS)," until additional information becomes available. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.47
BayesDel_addAF	Pathogenic	0.27	D
BayesDel_noAF	Pathogenic	0.58
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.89	D;.;.;D;D;D;.;.;.
Eigen	Pathogenic	0.96
Eigen_PC	Pathogenic	0.86
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D;D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.46	D
MetaRNN	Pathogenic	0.74	D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.0	H;.;.;.;.;.;.;.;.
PrimateAI	Pathogenic	0.92	D
PROVEAN	Pathogenic	-5.6	D;D;D;D;D;D;D;D;D
REVEL	Pathogenic	0.91
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		0.89
MutPred		0.53		Loss of phosphorylation at T390 (P = 0.0769);.;.;.;.;.;.;Loss of phosphorylation at T390 (P = 0.0769);.;
MVP		0.98
MPC		0.52
ClinPred		0.93	D
GERP RS		5.0
Varity_R		0.94
gMVP		0.87

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

LitVar

Other links and lift over

dbSNP: rs201880353; hg19: chr3-136045723;