2-21038062-G-C

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_000384.3(APOB):​c.433C>G​(p.Pro145Ala) variant causes a missense change. The variant allele was found at a frequency of 0.00000137 in 1,461,878 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. P145L) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

APOB
NM_000384.3 missense

Scores

2
4
11

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 5.03

Publications

18 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 2 ACMG points.

PM2
Very rare variant in population databases, with high coverage;

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000384.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
APOB
NM_000384.3
MANE Select
c.433C>Gp.Pro145Ala
missense
Exon 5 of 29NP_000375.3

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
APOB
ENST00000233242.5
TSL:1 MANE Select
c.433C>Gp.Pro145Ala
missense
Exon 5 of 29ENSP00000233242.1
APOB
ENST00000399256.4
TSL:1
c.433C>Gp.Pro145Ala
missense
Exon 5 of 17ENSP00000382200.4
APOB
ENST00000673739.2
n.384-807C>G
intron
N/AENSP00000501110.2

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD2 exomes
AF:
0.00000795
AC:
2
AN:
251488
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:
0.0000544
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000879
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1461878
Hom.:
0
Cov.:
32
AF XY:
0.00000138
AC XY:
1
AN XY:
727248
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33478
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.0000504
AC:
2
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5764
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1112002
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.550
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

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.:
33
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
Dec 10, 2021
New York Genome Center
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.433C>G (p.Pro145Ala) variant identified in the APOB gene substitutes a conserved Proline for Alanine at amino acid 145/4564 (exon 5/29). This variant is absent from gnomAD(v3.1.2) suggesting it is not a common benign variant in the populations represented in that database. In silico algorithms predict this variant to be Tolerated (SIFT; score:0.056) and Benign (REVEL; 0.215) to the function of the canonical transcript. This variant is absent from ClinVar, and to our current knowledge has not been reported in individuals with hypercholesterolemia. Given the lack of compelling evidence for its pathogenicity, the c.433C>G (p.Pro145Ala) variant identified in the APOB gene is reported as a Variant of Uncertain Significance.

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.10
BayesDel_addAF
Benign
-0.16
T
BayesDel_noAF
Benign
-0.30
CADD
Uncertain
24
DANN
Uncertain
0.99
DEOGEN2
Benign
0.16
T
Eigen
Pathogenic
0.70
Eigen_PC
Uncertain
0.66
FATHMM_MKL
Uncertain
0.96
D
LIST_S2
Benign
0.81
T
M_CAP
Benign
0.017
T
MetaRNN
Uncertain
0.47
T
MetaSVM
Benign
-0.76
T
PhyloP100
5.0
PrimateAI
Benign
0.41
T
PROVEAN
Pathogenic
-4.6
D
REVEL
Benign
0.21
Sift
Benign
0.071
T
Sift4G
Benign
0.22
T
Vest4
0.50
MutPred
0.56
Loss of glycosylation at P145 (P = 0.0721)
MVP
0.72
MPC
0.14
ClinPred
0.96
D
GERP RS
5.7
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
gMVP
0.71
Mutation Taster
=58/42
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: rs6752026; hg19: chr2-21260934; API