2-21037104-C-T

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 1P and 0B. PP3

The NM_000384.3(APOB):​c.689G>A​(p.Gly230Asp) variant causes a missense change. The variant allele was found at a frequency of 0.0000041 in 1,461,854 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 Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G230V) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000041 ( 0 hom. )

Consequence

APOB
NM_000384.3 missense

Scores

5
7
6

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 7.01

Publications

6 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: Uncertain_significance. The variant received 1 ACMG points.

PP3
MetaRNN computational evidence supports a deleterious effect, 0.745

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
APOBNM_000384.3 linkc.689G>A p.Gly230Asp missense_variant Exon 6 of 29 ENST00000233242.5 NP_000375.3

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
APOBENST00000233242.5 linkc.689G>A p.Gly230Asp missense_variant Exon 6 of 29 1 NM_000384.3 ENSP00000233242.1
APOBENST00000399256.4 linkc.689G>A p.Gly230Asp missense_variant Exon 6 of 17 1 ENSP00000382200.4
APOBENST00000673739.2 linkn.535G>A non_coding_transcript_exon_variant Exon 5 of 25 ENSP00000501110.2
APOBENST00000673882.2 linkn.535G>A non_coding_transcript_exon_variant Exon 5 of 23 ENSP00000501253.2

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.00000795
AC:
2
AN:
251432
AF XY:
0.00000736
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:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000410
AC:
6
AN:
1461854
Hom.:
0
Cov.:
32
AF XY:
0.00000550
AC XY:
4
AN XY:
727234
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86254
European-Finnish (FIN)
AF:
0.0000187
AC:
1
AN:
53418
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5744
European-Non Finnish (NFE)
AF:
0.00000450
AC:
5
AN:
1112006
Other (OTH)
AF:
0.00
AC:
0
AN:
60392
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.483
Heterozygous variant carriers
0
1
2
2
3
4
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome 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
GnomAD4 genome
Cov.:
32
Alfa
AF:
0.0000434
Hom.:
0
Bravo
AF:
0.00000378
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Hypercholesterolemia, autosomal dominant, type B;C4551990:Familial hypobetalipoproteinemia 1 Uncertain:1
Oct 17, 2019
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant has not been reported in the literature in individuals with APOB-related conditions. This sequence change replaces glycine with aspartic acid at codon 230 of the APOB protein (p.Gly230Asp). The glycine residue is moderately conserved and there is a moderate physicochemical difference between glycine and aspartic acid. This variant is present in population databases (rs755661819, ExAC 0.002%). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.14
BayesDel_addAF
Uncertain
0.13
D
BayesDel_noAF
Uncertain
-0.040
CADD
Uncertain
24
DANN
Uncertain
1.0
DEOGEN2
Benign
0.16
.;T
Eigen
Pathogenic
0.88
Eigen_PC
Pathogenic
0.85
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Benign
0.83
.;T
M_CAP
Benign
0.077
D
MetaRNN
Pathogenic
0.75
D;D
MetaSVM
Benign
-0.45
T
PhyloP100
7.0
PrimateAI
Uncertain
0.59
T
PROVEAN
Uncertain
-3.9
D;D
REVEL
Uncertain
0.47
Sift
Uncertain
0.0040
D;D
Sift4G
Pathogenic
0.0
D;D
Vest4
0.61
MutPred
0.42
Gain of ubiquitination at K229 (P = 0.0581);Gain of ubiquitination at K229 (P = 0.0581);
MVP
0.74
MPC
0.27
ClinPred
0.98
D
GERP RS
5.6
gMVP
0.65
Mutation Taster
=34/66
disease causing

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: rs755661819; hg19: chr2-21259976; API