19-44948822-C-G

Variant names:

• chr19-44948822-C-G
• rs120074111
• NM_000483.5:c.177C>G

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PVS1_Strong PM2 PP5

The NM_000483.5(APOC2):​c.177C>G​(p.Tyr59*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Pathogenic (no stars). Synonymous variant affecting the same amino acid position (i.e. Y59Y) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: APOC2 NM_000483.5 stop_gained
• Clinical Significance: Pathogenic no assertion criteria provided P:2
• Conservation: PhyloP100: 0.183
• Publications: 7 publications found

Genes affected

APOC2 (HGNC:609): (apolipoprotein C2) This gene encodes a lipid-binding protein belonging to the apolipoprotein gene family. The protein is secreted in plasma where it is a component of very low density lipoprotein. This protein activates the enzyme lipoprotein lipase, which hydrolyzes triglycerides and thus provides free fatty acids for cells. Mutations in this gene cause hyperlipoproteinemia type IB, characterized by hypertriglyceridemia, xanthomas, and increased risk of pancreatitis and early atherosclerosis. This gene is present in a cluster with other related apolipoprotein genes on chromosome 19. Naturally occurring read-through transcription exists between this gene and the neighboring upstream apolipoprotein C-IV (APOC4) gene. [provided by RefSeq, Mar 2011]

APOC4-APOC2 (HGNC:44426): (APOC4-APOC2 readthrough (NMD candidate)) This locus represents naturally occurring read-through transcription between the neighboring apolipoprotein C-IV (APOC4) and apolipoprotein C-II (APOC2) genes on chromosome 19. The read-through transcript is a candidate for nonsense-mediated mRNA decay (NMD), and is thus unlikely to produce a protein product. [provided by RefSeq, Mar 2011]

ACMG classification

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most 50 bp of the penultimate exon, not predicted to undergo nonsense mediated mRNA decay. There are 8 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 19-44948822-C-G is Pathogenic according to our data. Variant chr19-44948822-C-G is described in ClinVar as Pathogenic. ClinVar VariationId is 2580.Status of the report is no_assertion_criteria_provided, 0 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
APOC2	NM_000483.5	c.177C>G	p.Tyr59*	stop_gained	Exon 3 of 4	ENST00000252490.7	NP_000474.2
APOC4-APOC2	NR_037932.1	n.1384C>G		non_coding_transcript_exon_variant	Exon 5 of 6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
APOC2	ENST00000252490.7	c.177C>G	p.Tyr59*	stop_gained	Exon 3 of 4	2	NM_000483.5	ENSP00000252490.5
APOC4-APOC2	ENST00000589057.5	c.408C>G	p.Tyr136*	stop_gained	Exon 4 of 5	5		ENSP00000468139.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: no assertion criteria provided

Submissions by phenotype

APOLIPOPROTEIN C-II (BARI) Pathogenic:1

Aug 01, 1994

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

Familial apolipoprotein C-II deficiency Pathogenic:1

Aug 01, 1994

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.34
BayesDel_addAF	Pathogenic	0.51	D
BayesDel_noAF	Uncertain	0.020
CADD	Pathogenic	33
DANN	Uncertain	0.98
Eigen	Benign	-0.35
Eigen_PC	Benign	-0.71
FATHMM_MKL	Benign	0.17	N
MetaRNN	Benign	0.42	T
PhyloP100		0.18
Vest4		0.21
GERP RS		-0.38
Mutation Taster		=0/200	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.24		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.24		Position offset: 38

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

Other links and lift over

dbSNP: rs120074111; hg19: chr19-45452079;