11-116830794-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000040.3(APOC3):c.77C>T(p.Ala26Val) variant causes a missense 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. 13/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: APOC3 NM_000040.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.248

Genes affected

APOC3 (HGNC:610): (apolipoprotein C3) This gene encodes a protein component of triglyceride (TG)-rich lipoproteins (TRLs) including very low density lipoproteins (VLDL), high density lipoproteins (HDL) and chylomicrons. The encoded protein plays a role in role in the metabolism of these TRLs through multiple modes. This protein has been shown to promote the secretion of VLDL1, inhibit lipoprotein lipase enzyme activity, and delay catabolism of TRL remnants. Mutations in this gene are associated with low plasma triglyceride levels and reduced risk of ischemic cardiovascular disease, and hyperalphalipoproteinemia, which is characterized by elevated levels of high density lipoprotein (HDL) and HDL cholesterol in human patients. This gene and other related genes comprise an apolipoprotein gene cluster on chromosome 11. [provided by RefSeq, Sep 2017]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.20108467).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
APOC3	NM_000040.3	c.77C>T	p.Ala26Val	missense_variant	3/4	ENST00000227667.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
APOC3	ENST00000227667.8	c.77C>T	p.Ala26Val	missense_variant	3/4	1	NM_000040.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Cardiovascular phenotype Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

May 21, 2023

The p.A26V variant (also known as c.77C>T), located in coding exon 2 of the APOC3 gene, results from a C to T substitution at nucleotide position 77. The alanine at codon 26 is replaced by valine, an amino acid with similar properties. This amino acid position is conserved. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_addAF	Benign	-0.17	T
BayesDel_noAF	Benign	-0.48
Cadd	Benign	14
Dann	Benign	0.96
Eigen	Benign	-0.91
Eigen_PC	Benign	-0.99
FATHMM_MKL	Benign	0.12	N
LIST_S2	Benign	0.44	T;T;.;T
M_CAP	Uncertain	0.13	D
MetaRNN	Benign	0.20	T;T;T;T
MetaSVM	Benign	-0.71	T
MutationTaster	Benign	1.0	N;N
PrimateAI	Benign	0.27	T
PROVEAN	Uncertain	-2.8	D;N;N;.
REVEL	Benign	0.15
Sift	Benign	0.14	T;T;T;.
Sift4G	Benign	0.17	T;T;T;T
Polyphen		0.0010	.;B;.;.
Vest4		0.050, 0.058
MutPred		0.54		Loss of disorder (P = 0.0641);Loss of disorder (P = 0.0641);.;.;
MVP		0.80
MPC		0.083
ClinPred		0.15	T
GERP RS		-0.14
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.0
Varity_R		0.047
gMVP		0.24

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.19		Details are displayed if max score is > 0.2

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr11-116701510;