3-98588783-G-A

Variant names:

• chr3-98588783-G-A
• rs121917870
• NM_000097.7:c.883C>T

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM2 PM5 PP3_Strong

The NM_000097.7(CPOX):​c.883C>T​(p.His295Tyr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000031 in 1,613,994 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. H295D) has been classified as Pathogenic.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: CPOX NM_000097.7 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.56
• Publications: 4 publications found

Genes affected

CPOX (HGNC:2321): (coproporphyrinogen oxidase) The protein encoded by this gene is the sixth enzyme of the heme biosynthetic pathway. The encoded enzyme is soluble and found in the intermembrane space of mitochondria. This enzyme catalyzes the stepwise oxidative decarboxylation of coproporphyrinogen III to protoporphyrinogen IX, a precursor of heme. Defects in this gene are a cause of hereditary coproporphyria (HCP).[provided by RefSeq, Oct 2009]

CPOX Gene-Disease associations (from GenCC):

• CPOX-related hereditary coproporphyria

  Inheritance: SD Classification: DEFINITIVE Submitted by: ClinGen
• hereditary coproporphyria

  Inheritance: AD, AR Classification: STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, Genomics England PanelApp
• harderoporphyria

  Inheritance: AR Classification: STRONG, LIMITED Submitted by: Ambry Genetics, Genomics England PanelApp

ACMG classification

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr3-98588783-G-C is described in ClinVar as Pathogenic. ClinVar VariationId is 456.Status of the report is no_assertion_criteria_provided, 0 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.954

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000097.7. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CPOX	NM_000097.7	MANE Select	c.883C>T	p.His295Tyr	missense	Exon 4 of 7	NP_000088.3

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CPOX	ENST00000647941.2	MANE Select	c.883C>T	p.His295Tyr	missense	Exon 4 of 7	ENSP00000497326.1
	CPOX	ENST00000946176.1		c.970C>T	p.His324Tyr	missense	Exon 5 of 8	ENSP00000616235.1
	CPOX	ENST00000932270.1		c.880C>T	p.His294Tyr	missense	Exon 4 of 7	ENSP00000602329.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152156 Hom.: 0 Cov.: 33

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: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461838 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727232

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000360 AC: 4 AN: 1111964

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152156 Hom.: 0 Cov.: 33 AF XY: 0.0000135 AC XY: 1 AN XY: 74336

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.0000241 AC: 1 AN: 41430

American (AMR) AF: 0.00 AC: 0 AN: 15278

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5192

South Asian (SAS) AF: 0.00 AC: 0 AN: 4828

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10610

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68026

Other (OTH) AF: 0.00 AC: 0 AN: 2094

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000756

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.091
BayesDel_addAF	Pathogenic	0.23	D
BayesDel_noAF	Uncertain	0.090
CADD	Pathogenic	33
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.57	D
Eigen	Pathogenic	0.86
Eigen_PC	Pathogenic	0.87
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D
M_CAP	Uncertain	0.21	D
MetaRNN	Pathogenic	0.95	D
MetaSVM	Pathogenic	0.89	D
MutationAssessor	Uncertain	2.6	M
PhyloP100		9.6
PrimateAI	Uncertain	0.61	T
PROVEAN	Pathogenic	-5.6	D
REVEL	Pathogenic	0.82
Sift	Benign	0.031	D
Sift4G	Uncertain	0.030	D
Polyphen		0.95	P
Vest4		0.60
MutPred		0.79		Loss of disorder (P = 0.0834)
MVP		0.99
MPC		1.6
ClinPred		0.99	D
GERP RS		5.9
Varity_R		0.79
gMVP		0.87
Mutation Taster		=42/58	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.41		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.41		Position offset: -11

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

Other links and lift over

dbSNP: rs121917870; hg19: chr3-98307627;