NM_000384.3:c.2988C>T

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 2P and 6B. PM2BP4_StrongBP6BP7

The NM_000384.3(APOB):​c.2988C>T​(p.Thr996Thr) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000318 in 1,614,060 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.00026 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00032 ( 0 hom. )

Consequence

APOB
NM_000384.3 synonymous

Scores

2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:6

Conservation

PhyloP100: -0.526
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]

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ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -4 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.59).
BP6
Variant 2-21019734-G-A is Benign according to our data. Variant chr2-21019734-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 477806.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=5, Uncertain_significance=2}. Variant chr2-21019734-G-A is described in Lovd as [Likely_benign].
BP7
Synonymous conserved (PhyloP=-0.526 with no splicing effect.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
APOBNM_000384.3 linkc.2988C>T p.Thr996Thr synonymous_variant Exon 19 of 29 ENST00000233242.5 NP_000375.3 P04114Q7Z7Q0Q59HB3

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
APOBENST00000233242.5 linkc.2988C>T p.Thr996Thr synonymous_variant Exon 19 of 29 1 NM_000384.3 ENSP00000233242.1 P04114

Frequencies

GnomAD3 genomes
AF:
0.000263
AC:
40
AN:
152164
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.000145
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000393
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000830
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000338
Gnomad OTH
AF:
0.000478
GnomAD3 exomes
AF:
0.000251
AC:
63
AN:
251212
Hom.:
0
AF XY:
0.000258
AC XY:
35
AN XY:
135768
show subpopulations
Gnomad AFR exome
AF:
0.000185
Gnomad AMR exome
AF:
0.0000579
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.000785
Gnomad FIN exome
AF:
0.0000462
Gnomad NFE exome
AF:
0.000282
Gnomad OTH exome
AF:
0.000163
GnomAD4 exome
AF:
0.000324
AC:
473
AN:
1461778
Hom.:
0
Cov.:
32
AF XY:
0.000345
AC XY:
251
AN XY:
727180
show subpopulations
Gnomad4 AFR exome
AF:
0.0000896
Gnomad4 AMR exome
AF:
0.0000671
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.0000252
Gnomad4 SAS exome
AF:
0.000823
Gnomad4 FIN exome
AF:
0.0000187
Gnomad4 NFE exome
AF:
0.000332
Gnomad4 OTH exome
AF:
0.000381
GnomAD4 genome
AF:
0.000263
AC:
40
AN:
152282
Hom.:
0
Cov.:
32
AF XY:
0.000228
AC XY:
17
AN XY:
74466
show subpopulations
Gnomad4 AFR
AF:
0.000144
Gnomad4 AMR
AF:
0.000392
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.000830
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.000338
Gnomad4 OTH
AF:
0.000473
Alfa
AF:
0.000376
Hom.:
0
Bravo
AF:
0.000268
Asia WGS
AF:
0.000289
AC:
1
AN:
3478
EpiCase
AF:
0.000436
EpiControl
AF:
0.000178

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:2Benign:6
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Benign:2
Feb 03, 2021
Quest Diagnostics Nichols Institute San Juan Capistrano
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Oct 01, 2024
CeGaT Center for Human Genetics Tuebingen
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

APOB: BP4, BP7 -

Hypercholesterolemia, autosomal dominant, type B Uncertain:1
Jan 13, 2018
Illumina Laboratory Services, Illumina
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Familial hypobetalipoproteinemia 1 Uncertain:1
Jan 13, 2018
Illumina Laboratory Services, Illumina
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Hypercholesterolemia, autosomal dominant, type B;C4551990:Familial hypobetalipoproteinemia 1 Benign:1
Jan 29, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

APOB-related disorder Benign:1
May 31, 2024
PreventionGenetics, part of Exact Sciences
Significance: Likely benign
Review Status: no assertion criteria provided
Collection Method: clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Cardiovascular phenotype Benign:1
Apr 05, 2019
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. -

Familial hypercholesterolemia Benign:1
Jan 25, 2023
GENinCode PLC
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This is a synonymous (silent) variant that is not predicted by SpliceAI to impact splicing. In addition, it occurs at a nucleotide that is not conserved. Therefore this variant has been classified as Likely Benign (BP4, BP7). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.59
CADD
Benign
1.6
DANN
Benign
0.88

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.030
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.

Other links and lift over

dbSNP: rs137875230; hg19: chr2-21242606; COSMIC: COSV104576086; COSMIC: COSV104576086; API