rs879253804

Positions:

• chr13-100089226-G-A

Variant summary

Our verdict is Pathogenic. Variant got 22 ACMG points: 22P and 0B. PVS1 PM2 PP3_Strong PP5_Very_Strong

The NM_000282.4(PCCA):​c.105+1G>A variant causes a splice donor change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000221 in 1,357,966 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000022 (0 hom.)
• Consequence: PCCA NM_000282.4 splice_donor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 3.40

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]

ACMG classification

Verdict is Pathogenic. Variant got 22 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 13-100089226-G-A is Pathogenic according to our data. Variant chr13-100089226-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 218251.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PCCA	NM_000282.4	c.105+1G>A		splice_donor_variant		ENST00000376285.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PCCA	ENST00000376285.6	c.105+1G>A		splice_donor_variant		1	NM_000282.4	P1
PCCA	ENST00000376279.7	c.105+1G>A		splice_donor_variant		2
PCCA	ENST00000376286.8	c.105+1G>A		splice_donor_variant		2
PCCA	ENST00000647303.1	c.105+1G>A		splice_donor_variant, NMD_transcript_variant

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000221 AC: 3 AN: 1357966 Hom.: 0 Cov.: 31 AF XY: 0.00000150 AC XY: 1 AN XY: 667516

Gnomad4 AFR exome AF: 0.0000353

Gnomad4 AMR exome AF: 0.00

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: 9.42e-7

Gnomad4 OTH exome AF: 0.0000178

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Propionic acidemia Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Nov 27, 2023	This sequence change affects a donor splice site in intron 1 of the PCCA gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in PCCA are known to be pathogenic (PMID: 15464417). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. Disruption of this splice site has been observed in individual(s) with propionic acidemia (PMID: 27227689, 35331292). ClinVar contains an entry for this variant (Variation ID: 218251). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	research	Institute of Medical Genetics and Genomics, Sir Ganga Ram Hospital	Jan 01, 2013	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.19
CADD	Pathogenic	35
DANN	Uncertain	0.99
Eigen	Pathogenic	0.98
Eigen_PC	Pathogenic	0.79
FATHMM_MKL	Benign	0.69	D
MutationTaster	Benign	1.0	D;D;D
GERP RS		4.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		2.9

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.27		Position offset: 23
DS_DL_spliceai		0.99		Position offset: -1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs879253804; hg19: chr13-100741480;