19-44948512-G-C

Variant names:

• chr19-44948512-G-C
• rs150887575
• NM_000483.5:c.34G>C

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000483.5(APOC2):​c.34G>C​(p.Val12Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,856 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/21 in silico tools predict a benign 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. V12I) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: APOC2 NM_000483.5 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.914
• Publications: 6 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: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.09579578).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000483.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	APOC2	NM_000483.5	MANE Select	c.34G>C	p.Val12Leu	missense	Exon 2 of 4	NP_000474.2
	APOC4-APOC2	NR_037932.1		n.1241G>C		non_coding_transcript_exon	Exon 4 of 6

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	APOC2	ENST00000252490.7	TSL:2 MANE Select	c.34G>C	p.Val12Leu	missense	Exon 2 of 4	ENSP00000252490.5	P02655
	APOC4-APOC2	ENST00000589057.5	TSL:5	c.265G>C	p.Val89Leu	missense	Exon 3 of 5	ENSP00000468139.1	K7ER74
	APOC2	ENST00000896555.1		c.34G>C	p.Val12Leu	missense	Exon 2 of 4	ENSP00000566614.1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251484 AF XY: 0.00

Gnomad AFR exome AF: 0.0000615

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461856 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727232

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

African (AFR) AF: 0.0000299 AC: 1 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

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

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53414

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

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111988

Other (OTH) AF: 0.00 AC: 0 AN: 60392

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.00233887), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 31

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_addAF	Benign	-0.18	T
BayesDel_noAF	Benign	-0.32
CADD	Benign	0.13
DANN	Benign	0.92
DEOGEN2	Benign	0.018	T
Eigen	Benign	-1.1
Eigen_PC	Benign	-1.2
FATHMM_MKL	Benign	0.050	N
LIST_S2	Benign	0.75	T
M_CAP	Benign	0.068	D
MetaRNN	Benign	0.096	T
MetaSVM	Benign	-0.86	T
MutationAssessor	Benign	1.8	L
PhyloP100		-0.91
PROVEAN	Benign	-1.5	N
REVEL	Benign	0.16
Sift	Benign	0.034	D
Sift4G	Benign	0.67	T
Polyphen		0.24	B
Vest4		0.14
MutPred		0.39		Loss of stability (P = 0.0397)
MVP		0.32
MPC		0.18
ClinPred		0.058	T
GERP RS		-2.0
PromoterAI		0.061	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.087
gMVP		0.44
Mutation Taster		=91/9	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs150887575; hg19: chr19-45451769;