2-21042380-G-T

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 0P and 3B. BP4_ModerateBP6

The NM_000384.3(APOB):​c.218C>A​(p.Ala73Asp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000545 in 1,613,548 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/20 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 0.0000066 ( 0 hom., cov: 31)
Exomes 𝑓: 0.000060 ( 0 hom. )

Consequence

APOB
NM_000384.3 missense

Scores

3
15

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4B:3

Conservation

PhyloP100: 1.10

Publications

4 publications found
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 Gene-Disease associations (from GenCC):
  • hypercholesterolemia, autosomal dominant, type B
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, G2P, Labcorp Genetics (formerly Invitae), ClinGen, Ambry Genetics
  • familial hypobetalipoproteinemia 1
    Inheritance: AR, AD, SD Classification: DEFINITIVE, STRONG Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae), Genomics England PanelApp, ClinGen
  • homozygous familial hypercholesterolemia
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -3 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.23442566).
BP6
Variant 2-21042380-G-T is Benign according to our data. Variant chr2-21042380-G-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 548044.We mark this variant Likely_benign, oryginal submission is: [Conflicting_classifications_of_pathogenicity].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
APOBNM_000384.3 linkc.218C>A p.Ala73Asp missense_variant Exon 3 of 29 ENST00000233242.5 NP_000375.3 P04114Q7Z7Q0Q59HB3

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
APOBENST00000233242.5 linkc.218C>A p.Ala73Asp missense_variant Exon 3 of 29 1 NM_000384.3 ENSP00000233242.1 P04114
APOBENST00000399256.4 linkc.218C>A p.Ala73Asp missense_variant Exon 3 of 17 1 ENSP00000382200.4 A8MUN2
APOBENST00000673739.2 linkn.218C>A non_coding_transcript_exon_variant Exon 3 of 25 ENSP00000501110.2 A0A669KB70
APOBENST00000673882.2 linkn.218C>A non_coding_transcript_exon_variant Exon 3 of 23 ENSP00000501253.2 A0A669KB70

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152134
Hom.:
0
Cov.:
31
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000318
AC:
8
AN:
251496
AF XY:
0.0000441
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 FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000703
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000595
AC:
87
AN:
1461414
Hom.:
0
Cov.:
31
AF XY:
0.0000523
AC XY:
38
AN XY:
727052
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33468
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86240
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53418
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5692
European-Non Finnish (NFE)
AF:
0.0000774
AC:
86
AN:
1111660
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60378
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.468
Heterozygous variant carriers
0
4
9
13
18
22
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
4
8
12
16
20
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152134
Hom.:
0
Cov.:
31
AF XY:
0.00
AC XY:
0
AN XY:
74302
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41414
American (AMR)
AF:
0.00
AC:
0
AN:
15278
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5194
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4818
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10610
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68028
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000772
Hom.:
0
Bravo
AF:
0.0000340
TwinsUK
AF:
0.000270
AC:
1
ALSPAC
AF:
0.00
AC:
0
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000116
AC:
1
ExAC
AF:
0.0000412
AC:
5
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:4Benign:3
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Hypercholesterolemia, autosomal dominant, type B;C4551990:Familial hypobetalipoproteinemia 1 Uncertain:2Benign:1
Feb 11, 2022
New York Genome Center
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.218C>A variant identified in APOB has previously been reported in the literature in individuals with dyslipidemia [PMID:24503134, 33303402] and deposited in ClinVar as variant of unknown significance [ClinVar ID: 548044]. This variant is observed in 17 alleles (~0.003% minor allele frequency; 0 homozygote) in population databases (gnomAD v2.1.1 and v3.1.2, TOPMed Freeze 8), suggesting it is not a common benign variant in the populations represented in those databases. The c.218C>A variant is located in exon 3 of this 29-exon gene, and predicted to replace an alanine amino acid with aspartate at codon 73 (p.(Ala73Asp) within N-terminal Vitellogenin domain. In silico predictions are inconclusive of deleterious effect (CADD v1.6= 22.2, REVEL= 0.129); however, there are no functional studies to support or refute these predictions. Based on available evidence this c.218C>A p.(Ala73Asp) variant identified in APOB is classified as a Variant of Uncertain Significance. -

Jan 05, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Aug 27, 2021
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Hypercholesterolemia, familial, 1 Uncertain:1
Jan 02, 2018
Robarts Research Institute, Western University
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Familial hypercholesterolemia Uncertain:1
Mar 07, 2018
Color Diagnostics, LLC DBA Color Health
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Benign:1
May 01, 2023
CeGaT Center for Human Genetics Tuebingen
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

APOB: BP4 -

Cardiovascular phenotype Benign:1
Mar 13, 2024
Ambry Genetics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.23
BayesDel_addAF
Benign
-0.32
T
BayesDel_noAF
Benign
-0.51
CADD
Benign
20
DANN
Benign
0.97
DEOGEN2
Benign
0.046
.;T
Eigen
Benign
-0.44
Eigen_PC
Benign
-0.51
FATHMM_MKL
Uncertain
0.94
D
LIST_S2
Benign
0.78
.;T
M_CAP
Benign
0.013
T
MetaRNN
Benign
0.23
T;T
MetaSVM
Benign
-0.99
T
PhyloP100
1.1
PrimateAI
Benign
0.29
T
PROVEAN
Benign
-2.3
N;D
REVEL
Benign
0.13
Sift
Uncertain
0.0050
D;D
Sift4G
Uncertain
0.0020
D;D
Vest4
0.30
MVP
0.57
MPC
0.063
ClinPred
0.12
T
GERP RS
-0.027
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1
gMVP
0.87
Mutation Taster
=83/17
polymorphism

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

Other links and lift over

dbSNP: rs377171241; hg19: chr2-21265252; API