2-21013526-G-A

Position:

chr2-21013526-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2PP3

The NM_000384.3(APOB):c.3850C>T(p.Arg1284Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000403 in 1,614,024 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.00014 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000029 ( 0 hom. )

Consequence

APOB
NM_000384.3 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4B:1

Conservation

PhyloP100: 0.411

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 3 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.773

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
APOB	NM_000384.3 linkuse as main transcript	c.3850C>T	p.Arg1284Trp	missense_variant	25/29	ENST00000233242.5	NP_000375.3	P04114Q7Z7Q0Q59HB3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
APOB	ENST00000233242.5 linkuse as main transcript	c.3850C>T	p.Arg1284Trp	missense_variant	25/29	1	NM_000384.3	ENSP00000233242.1		P04114

Frequencies

GnomAD3 genomes

AF:

0.000145

AC:

AN:

152066

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000338

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000193

Gnomad SAS

AF:

0.000417

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000735

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000398

AC:

AN:

251066

Hom.:

AF XY:

0.0000368

AC XY:

AN XY:

135826

show subpopulations

Gnomad AFR exome

AF:

0.000187

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad SAS exome

AF:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000440

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000294

AC:

AN:

1461840

Hom.:

Cov.:

AF XY:

0.0000330

AC XY:

AN XY:

727222

show subpopulations

Gnomad4 AFR exome

AF:

0.000149

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.000101

Gnomad4 SAS exome

AF:

0.0000696

Gnomad4 FIN exome

AF:

0.0000187

Gnomad4 NFE exome

AF:

0.0000207

Gnomad4 OTH exome

AF:

0.0000662

GnomAD4 genome

AF:

0.000145

AC:

AN:

152184

Hom.:

Cov.:

AF XY:

0.000161

AC XY:

AN XY:

74390

show subpopulations

Gnomad4 AFR

AF:

0.000337

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000193

Gnomad4 SAS

AF:

0.000417

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000735

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000381

Hom.:

Bravo

AF:

0.000106

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.0000330

AC:

Asia WGS

AF:

0.000289

AC:

AN:

3478

EpiCase

AF:

0.00

EpiControl

AF:

0.000119

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:4Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

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

Uncertain:1Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	Fulgent Genetics, Fulgent Genetics	Nov 01, 2021	- -
Benign, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Nov 13, 2023	- -

Hypercholesterolemia, autosomal dominant, type B

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

May 06, 2021

Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as VUS-3A. Following criteria are met: 0102 - Loss of function is a known mechanism of disease in this gene and is associated with familial hypercholesterolemia 2 (MIM#144010). (I) 0108 - This gene is associated with both recessive and dominant disease. Familial hypercholesterolemia 2 (MIM#144010) is inherited in an autosomal dominant manner, whereas hypobetalipoproteinemia (MIM#615558) is recessive (OMIM). (I) 0112 - The condition associated with this gene has incomplete penetrance (GeneReviews). (I) 0200 - Variant is predicted to result in a missense amino acid change from arginine to tryptophan. (I) 0251 - This variant is heterozygous. (I) 0302 - Variant is present in gnomAD (v3) <0.001 for a dominant condition (22 heterozygotes, 0 homozygotes). (SP) 0309 - Alternative amino acid changes at the same position have been observed in gnomAD (v2 & v3) (5 heterozygotes, 0 homozygotes). (I) 0501 - Missense variant consistently predicted to be damaging by multiple in silico tools or highly conserved with a major amino acid change. (SP) 0604 - Variant is not located in an established domain, motif, hotspot or informative constraint region. (I) 0710 - Another missense variant comparable to the one identified in this case has inconclusive previous evidence for pathogenicity. An alternative change to glutamine at the same residue has previously been reported as a VUS (ClinVar). (I) 0809 - Previous evidence of pathogenicity for this variant is inconclusive. The variant has previously been reported as a VUS and has been observed in an unaffected control (ClinVar, PMID: 30420299). (I) 0905 - No published segregation evidence has been identified for this variant. (I) 1007 - No published functional evidence has been identified for this variant. (I) 1102 - Strong phenotype match for this individual. (SP) 1208 - Inheritance information for this variant is not currently available in this individual. (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -

Hypercholesterolemia, familial, 1

Uncertain:1

Uncertain significance, criteria provided, single submitter

research

Laboratory of Genetics and Molecular Cardiology, University of São Paulo

Mar 01, 2016

- -

Cardiovascular phenotype

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 26, 2022

The p.R1284W variant (also known as c.3850C>T), located in coding exon 25 of the APOB gene, results from a C to T substitution at nucleotide position 3850. The arginine at codon 1284 is replaced by tryptophan, an amino acid with dissimilar properties. This amino acid position is not well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. 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

0.14

BayesDel_addAF

Benign

-0.10

BayesDel_noAF

Benign

-0.10

CADD

Uncertain

DANN

Pathogenic

1.0

Eigen

Uncertain

0.27

Eigen_PC

Benign

0.17

FATHMM_MKL

Benign

0.64

M_CAP

Benign

0.051

MetaRNN

Pathogenic

0.77

MetaSVM

Benign

-0.98

PrimateAI

Uncertain

0.49

PROVEAN

Pathogenic

-4.7

REVEL

Benign

0.19

Sift

Uncertain

0.0030

Sift4G

Pathogenic

0.0

Vest4

0.89

MVP

0.72

MPC

0.28

ClinPred

0.86

GERP RS

4.4

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

gMVP

0.76

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.010

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