rs768005049

Positions:

chr2-21015113-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2BP4

The NM_000384.3(APOB):c.3656C>T(p.Thr1219Ile) variant causes a missense change. The variant allele was found at a frequency of 0.0000186 in 1,614,064 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000017 ( 0 hom. )

Consequence

APOB
NM_000384.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 6.73

Variant links:

Genes affected

APOB (HGNC:603): (apolipoprotein B) This gene product is the main apolipoprotein of chylomicrons and low density lipoproteins (LDL), and is the ligand for the LDL receptor. It occurs in plasma as two main isoforms, apoB-48 and apoB-100: the former is synthesized exclusively in the gut and the latter in the liver. The intestinal and the hepatic forms of apoB are encoded by a single gene from a single, very long mRNA. The two isoforms share a common N-terminal sequence. The shorter apoB-48 protein is produced after RNA editing of the apoB-100 transcript at residue 2180 (CAA->UAA), resulting in the creation of a stop codon, and early translation termination. Mutations in this gene or its regulatory region cause hypobetalipoproteinemia, normotriglyceridemic hypobetalipoproteinemia, and hypercholesterolemia due to ligand-defective apoB, diseases affecting plasma cholesterol and apoB levels. [provided by RefSeq, Dec 2019]

APOB links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 1 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.35371).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
APOB	NM_000384.3 linkuse as main transcript	c.3656C>T	p.Thr1219Ile	missense_variant	23/29	ENST00000233242.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris
APOB	ENST00000233242.5 linkuse as main transcript	c.3656C>T	p.Thr1219Ile	missense_variant	23/29	1	NM_000384.3	P1
APOB	ENST00000673739.2 linkuse as main transcript	c.*2962C>T		3_prime_UTR_variant, NMD_transcript_variant	22/25
APOB	ENST00000673882.2 linkuse as main transcript	c.*2751C>T		3_prime_UTR_variant, NMD_transcript_variant	21/23

Frequencies

GnomAD3 genomes

AF:

0.0000329

AC:

AN:

152174

Hom.:

Cov.:

show subpopulations

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:

0.0000735

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000795

AC:

AN:

251434

Hom.:

AF XY:

0.0000147

AC XY:

AN XY:

135882

show subpopulations

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:

0.0000176

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000171

AC:

AN:

1461890

Hom.:

Cov.:

AF XY:

0.0000193

AC XY:

AN XY:

727246

show subpopulations

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:

0.0000189

Gnomad4 OTH exome

AF:

0.0000662

GnomAD4 genome

AF:

0.0000329

AC:

AN:

152174

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74324

show subpopulations

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:

0.0000735

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000142

Hom.:

Bravo

AF:

0.0000151

ExAC

AF:

0.00000824

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Hypercholesterolemia, autosomal dominant, type B;C4551990:Familial hypobetalipoproteinemia 1

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Aug 27, 2021

This sequence change replaces threonine with isoleucine at codon 1219 of the APOB protein (p.Thr1219Ile). The threonine residue is highly conserved and there is a moderate physicochemical difference between threonine and isoleucine. This variant is present in population databases (rs768005049, ExAC 0.001%). This variant has not been reported in the literature in individuals affected with APOB-related conditions. ClinVar contains an entry for this variant (Variation ID: 548053). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The isoleucine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Hypercholesterolemia, familial, 1

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Robarts Research Institute, Western University

Jan 02, 2018

- -

Cardiovascular phenotype

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jul 08, 2022

The p.T1219I variant (also known as c.3656C>T), located in coding exon 23 of the APOB gene, results from a C to T substitution at nucleotide position 3656. The threonine at codon 1219 is replaced by isoleucine, 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

Uncertain

0.40

BayesDel_addAF

Benign

-0.024

BayesDel_noAF

Benign

-0.26

CADD

Benign

DANN

Uncertain

1.0

Eigen

Pathogenic

0.78

Eigen_PC

Pathogenic

0.77

FATHMM_MKL

Pathogenic

0.97

M_CAP

Benign

0.038

MetaRNN

Benign

0.35

MetaSVM

Benign

-1.2

MutationTaster

Benign

1.0

PrimateAI

Benign

0.44

PROVEAN

Uncertain

-3.9

REVEL

Uncertain

0.32

Sift

Uncertain

0.0010

Sift4G

Pathogenic

0.0

Vest4

0.20

MutPred

0.58

Gain of sheet (P = 0.0477);

MVP

0.69

MPC

0.045

ClinPred

0.97

GERP RS

5.5

gMVP

0.84

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over