17-42562674-C-CT

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PVS1_Strong PM2 PP5

The NM_025233.7(COASY):c.53dup(p.Ala19SerfsTer45) variant causes a frameshift change. The variant allele was found at a frequency of 0.0000202 in 1,537,008 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. L18L) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.000026 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000019 (0 hom.)
• Consequence: COASY NM_025233.7 frameshift
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 5.55

Genes affected

COASY (HGNC:29932): (Coenzyme A synthase) Coenzyme A (CoA) functions as a carrier of acetyl and acyl groups in cells and thus plays an important role in numerous synthetic and degradative metabolic pathways in all organisms. In eukaryotes, CoA and its derivatives are also involved in membrane trafficking and signal transduction. This gene encodes the bifunctional protein coenzyme A synthase (CoAsy) which carries out the last two steps in the biosynthesis of CoA from pantothenic acid (vitamin B5). The phosphopantetheine adenylyltransferase domain of this bifunctional protein catalyzes the conversion of 4'-phosphopantetheine into dephospho-coenzyme A (dpCoA) while its dephospho-CoA kinase domain completes the final step by phosphorylating dpCoA to form CoA. Mutations in this gene are associated with neurodegeneration with brain iron accumulation (NBIA). Alternative splicing results in multiple isoforms. [provided by RefSeq, Apr 2014]

ACMG classification

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 17 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 17-42562674-C-CT is Pathogenic according to our data. Variant chr17-42562674-C-CT is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 2079887.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
COASY	NM_025233.7	c.53dup	p.Ala19SerfsTer45	frameshift_variant	1/9	ENST00000393818.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
COASY	ENST00000393818.3	c.53dup	p.Ala19SerfsTer45	frameshift_variant	1/9	1	NM_025233.7	P1

Frequencies

GnomAD3 genomes AF: 0.0000263 AC: 4 AN: 152230 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

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: 0.0000441

Gnomad OTH AF: 0.000478

GnomAD3 exomes AF: 0.0000204 AC: 4 AN: 196138 Hom.: 0 AF XY: 0.0000190 AC XY: 2 AN XY: 105362

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

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: 0.0000424

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000195 AC: 27 AN: 1384778 Hom.: 0 Cov.: 30 AF XY: 0.0000205 AC XY: 14 AN XY: 681636

Gnomad4 AFR exome AF: 0.00

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: 0.0000241

Gnomad4 OTH exome AF: 0.0000175

GnomAD4 genome AF: 0.0000263 AC: 4 AN: 152230 Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2 AN XY: 74372

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000441

Gnomad4 OTH AF: 0.000478

Bravo AF: 0.0000302

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Neurodegeneration with brain iron accumulation 6 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Nov 03, 2022

For these reasons, this variant has been classified as Pathogenic. This variant has not been reported in the literature in individuals affected with COASY-related conditions. This variant is present in population databases (rs751753677, gnomAD 0.004%). This sequence change creates a premature translational stop signal (p.Ala19Serfs*45) in the COASY gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in COASY are known to be pathogenic (PMID: 24360804, 30089828). -

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Nov 14, 2022

Does not currently meet published gene-disease clinical validity criteria for this gene (Smith, 2017) Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

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: rs751753677; hg19: chr17-40714692;