rs794727479

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2PP3_Strong

The NM_000282.4(PCCA):​c.223G>C​(p.Ala75Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000248 in 1,610,266 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 Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. A75A) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

PCCA
NM_000282.4 missense

Scores

13
5
1

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 7.80

Publications

3 publications found
Variant links:
Genes affected
PCCA (HGNC:8653): (propionyl-CoA carboxylase subunit alpha) The protein encoded by this gene is the alpha subunit of the heterodimeric mitochondrial enzyme Propionyl-CoA carboxylase. PCCA encodes the biotin-binding region of this enzyme. Mutations in either PCCA or PCCB (encoding the beta subunit) lead to an enzyme deficiency resulting in propionic acidemia. Multiple transcript variants encoding different isoforms have been found for this gene.[provided by RefSeq, May 2010]
PCCA Gene-Disease associations (from GenCC):
  • propionic acidemia
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Labcorp Genetics (formerly Invitae), Myriad Women’s Health, ClinGen, Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

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, 0.985

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
PCCANM_000282.4 linkc.223G>C p.Ala75Pro missense_variant Exon 3 of 24 ENST00000376285.6 NP_000273.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
PCCAENST00000376285.6 linkc.223G>C p.Ala75Pro missense_variant Exon 3 of 24 1 NM_000282.4 ENSP00000365462.1

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152096
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1458170
Hom.:
0
Cov.:
29
AF XY:
0.00
AC XY:
0
AN XY:
725576
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33382
American (AMR)
AF:
0.00
AC:
0
AN:
44700
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26092
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39562
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86094
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53382
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5490
European-Non Finnish (NFE)
AF:
9.02e-7
AC:
1
AN:
1109244
Other (OTH)
AF:
0.00
AC:
0
AN:
60224
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.450
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152096
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74302
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41410
American (AMR)
AF:
0.00
AC:
0
AN:
15270
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5196
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10588
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68012
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.625
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Propionic acidemia Uncertain:2
Jun 04, 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. -

May 28, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with proline, which is neutral and non-polar, at codon 75 of the PCCA protein (p.Ala75Pro). This variant is present in population databases (rs794727479, gnomAD 0.01%). This missense change has been observed in individual(s) with clinical features of propionic acidemia (PMID: 10329019, 27900673). This variant is also known as 148G->C (A50P). ClinVar contains an entry for this variant (Variation ID: 196245). 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 PCCA protein function. Experimental studies have shown that this missense change affects PCCA function (PMID: 12385775). 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. -

not specified Uncertain:1
Apr 05, 2023
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: PCCA c.223G>C (p.Ala75Pro) results in a non-conservative amino acid change located in the N-terminal domain (IPR005481) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant was absent in 250608 control chromosomes (gnomAD). The variant, c.223G>C (aka c.148G>C / A50P) has been reported in the literature in at least two compound heterozygous individuals who were affected with a milder form of Propionic Acidemia (Campeau_1999, Cappuccio_2016). These data indicate that the variant may be associated with disease. A publication reported experimental evidence evaluating an impact on protein function, and demonstrated decreased enzyme activity (likely as a result of increased degradation), with a relatively high residual activity (15-30%) in a PCCA-deficient fibroblast system (Clavero_2002). Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as VUS-possibly pathogenic. -

not provided Uncertain:1
Dec 02, 2014
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.98
BayesDel_addAF
Pathogenic
0.57
D
BayesDel_noAF
Pathogenic
0.57
CADD
Pathogenic
29
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.98
.;.;D
Eigen
Pathogenic
1.0
Eigen_PC
Pathogenic
0.98
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Pathogenic
0.99
D;D;D
M_CAP
Pathogenic
0.36
D
MetaRNN
Pathogenic
0.99
D;D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Pathogenic
3.8
.;H;H
PhyloP100
7.8
PrimateAI
Uncertain
0.75
T
PROVEAN
Uncertain
-4.1
D;D;D
REVEL
Pathogenic
0.95
Sift
Uncertain
0.0050
D;D;D
Sift4G
Uncertain
0.0070
D;D;D
Polyphen
0.98
D;.;D
Vest4
0.95
MutPred
0.95
.;Gain of catalytic residue at A75 (P = 0.0372);Gain of catalytic residue at A75 (P = 0.0372);
MVP
0.99
MPC
0.71
ClinPred
1.0
D
GERP RS
5.8
Varity_R
0.94
gMVP
0.97
Mutation Taster
=6/94
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
Splicevardb
2.0
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

Other links and lift over

dbSNP: rs794727479; hg19: chr13-100764134; API