2-21023036-C-T

Position:

chr2-21023036-C-T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2BP4_Strong

The NM_000384.3(APOB):c.2611G>A(p.Ala871Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000164 in 1,613,934 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/19 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.00012 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00017 ( 0 hom. )

Consequence

APOB
NM_000384.3 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5B:1

Conservation

PhyloP100: 0.532

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 Likely_benign. Variant got -2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.063818395).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
APOB	NM_000384.3 linkuse as main transcript	c.2611G>A	p.Ala871Thr	missense_variant	18/29	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.2611G>A	p.Ala871Thr	missense_variant	18/29	1	NM_000384.3	ENSP00000233242.1		P04114

Frequencies

GnomAD3 genomes

AF:

0.000125

AC:

AN:

152150

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000966

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:

0.000220

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.000108

AC:

AN:

250984

Hom.:

AF XY:

0.0000811

AC XY:

AN XY:

135658

show subpopulations

Gnomad AFR exome

AF:

0.000185

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:

0.000203

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.000168

AC:

245

AN:

1461784

Hom.:

Cov.:

AF XY:

0.000175

AC XY:

127

AN XY:

727192

show subpopulations

Gnomad4 AFR exome

AF:

0.000119

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:

0.0000187

Gnomad4 NFE exome

AF:

0.000210

Gnomad4 OTH exome

AF:

0.0000994

GnomAD4 genome

AF:

0.000125

AC:

AN:

152150

Hom.:

Cov.:

AF XY:

0.000135

AC XY:

AN XY:

74330

show subpopulations

Gnomad4 AFR

AF:

0.0000966

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:

0.000220

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000111

Hom.:

Bravo

AF:

0.0000945

TwinsUK

AF:

0.000539

AC:

ALSPAC

AF:

0.00

AC:

ESP6500AA

AF:

0.000454

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.000107

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.000296

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:5Benign: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	Jul 19, 2021	- -
Likely benign, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Dec 29, 2023	- -

Hypercholesterolemia, autosomal dominant, type B

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Apr 27, 2017

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

not provided

Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

Department of Pathology and Laboratory Medicine, Sinai Health System

The APOB p.Ala871Thr variant was not identified in the literature nor was it identified in Cosmic. The variant was identified in dbSNP (ID: rs144622446), ClinVar (classified as a VUS by Color; associated condition is Familial hypercholesterolemia). The variant was also found in control databases in 32 of 282392 chromosomes at a frequency of 0.000113 (Genome Aggregation Database Feb 27, 2017) and was observed in the following populations: European (non-Finnish) in 27 of 128764 chromosomes (freq: 0.00021), African in 4 of 24948 chromosomes (freq: 0.00016) and Other in 1 of 7216 chromosomes (freq: 0.000139), while the variant was not observed in the Latino, Ashkenazi Jewish, East Asian, European (Finnish) and South Asian populations. The variant occurs outside of the splicing consensus sequence and in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer) do not predict a difference in splicing. The p.Ala871 residue is not conserved in mammals or other organisms, and none of the computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) suggest a high likelihood of impact to the protein; however, this information is not predictive enough to rule out pathogenicity. In summary, based on the above information the clinical significance of this variant cannot be determined with certainty at this time. This variant is classified as a variant of uncertain significance. -

Familial hypobetalipoproteinemia 1

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Apr 27, 2017

Cardiovascular phenotype

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 06, 2023

The c.2611G>A (p.A871T) alteration is located in exon 18 (coding exon 18) of the APOB gene. This alteration results from a G to A substitution at nucleotide position 2611, causing the alanine (A) at amino acid position 871 to be replaced by a threonine (T). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.095

BayesDel_addAF

Benign

-0.54

BayesDel_noAF

Benign

-0.73

CADD

Benign

9.0

DANN

Uncertain

1.0

Eigen

Benign

-0.62

Eigen_PC

Benign

-0.65

FATHMM_MKL

Benign

0.41

M_CAP

Benign

0.0064

MetaRNN

Benign

0.064

MetaSVM

Benign

-1.0

PrimateAI

Benign

0.26

PROVEAN

Benign

-1.5

REVEL

Benign

0.031

Sift

Benign

0.10

Sift4G

Benign

0.12

Vest4

0.078

MVP

0.40

MPC

0.053

ClinPred

0.031

GERP RS

0.16

gMVP

0.60

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