2-21012603-C-T

Variant names:

Variant summary

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

The NM_000384.3(APOB):c.4265G>A(p.Cys1422Tyr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000169 in 1,613,184 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 5/6 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. C1422R) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00020 ( 0 hom., cov: 33)

Exomes 𝑓: 0.00017 ( 0 hom. )

Consequence

APOB
NM_000384.3 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3B:1

Conservation

PhyloP100: 0.910

Publications

33 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

APOB links:

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=0.07234293).

BP6

Variant 2-21012603-C-T is Benign according to our data. Variant chr2-21012603-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 431497.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
APOB	NM_000384.3 link	c.4265G>A	p.Cys1422Tyr	missense_variant	Exon 26 of 29	ENST00000233242.5	NP_000375.3	P04114Q7Z7Q0Q59HB3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
APOB	ENST00000233242.5 link	c.4265G>A	p.Cys1422Tyr	missense_variant	Exon 26 of 29	1	NM_000384.3	ENSP00000233242.1	P04114
APOB	ENST00000673739.2 link	n.*3571G>A		non_coding_transcript_exon_variant	Exon 25 of 25			ENSP00000501110.2	A0A669KB70
APOB	ENST00000673739.2 link	n.*3571G>A		3_prime_UTR_variant	Exon 25 of 25			ENSP00000501110.2	A0A669KB70

Frequencies

GnomAD3 genomes

AF:

0.000197

AC:

AN:

152208

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000217

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000131

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:

0.000235

Gnomad OTH

AF:

0.00143

GnomAD4 exome

AF:

0.000166

AC:

243

AN:

1460976

Hom.:

Cov.:

AF XY:

0.000154

AC XY:

112

AN XY:

726852

show subpopulations

African (AFR)

AF:

0.000478

AC:

AN:

33462

American (AMR)

AF:

0.000157

AC:

AN:

44720

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26128

East Asian (EAS)

AF:

0.00

AC:

AN:

39696

South Asian (SAS)

AF:

0.0000348

AC:

AN:

86204

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53198

Middle Eastern (MID)

AF:

0.00347

AC:

AN:

5764

European-Non Finnish (NFE)

AF:

0.000166

AC:

185

AN:

1111426

Other (OTH)

AF:

0.000199

AC:

AN:

60378

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.510

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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:

0.000197

AC:

AN:

152208

Hom.:

Cov.:

AF XY:

0.000229

AC XY:

AN XY:

74352

show subpopulations

African (AFR)

AF:

0.000217

AC:

AN:

41448

American (AMR)

AF:

0.000131

AC:

AN:

15286

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5196

South Asian (SAS)

AF:

0.00

AC:

AN:

4828

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10612

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.000235

AC:

AN:

68048

Other (OTH)

AF:

0.00143

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.493

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<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:

0.000207

Hom.:

Bravo

AF:

0.000257

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Hypercholesterolemia, autosomal dominant, type B;C4551990:Familial hypobetalipoproteinemia 1

Uncertain:1

Nov 20, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces cysteine, which is neutral and slightly polar, with tyrosine, which is neutral and polar, at codon 1422 of the APOB protein (p.Cys1422Tyr). This variant is present in population databases (no rsID available, gnomAD 0.03%). This variant has not been reported in the literature in individuals affected with APOB-related conditions. ClinVar contains an entry for this variant (Variation ID: 431497). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt APOB protein function with a negative predictive value of 95%. 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. -

Hypercholesterolemia, familial, 1

Uncertain:1

Mar 01, 2016

Laboratory of Genetics and Molecular Cardiology, University of São Paulo

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:research

- -

not provided

Uncertain:1

Dec 13, 2019

Mayo Clinic Laboratories, Mayo Clinic

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

not specified

Benign:1

Jul 24, 2025

Molecular Diagnostic Laboratory for Inherited Cardiovascular Disease, Montreal Heart Institute

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

BS1;BP4 -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.13

BayesDel_noAF

Benign

-0.83

CADD

Benign

4.7

(source)

MetaRNN

Benign

0.072

PhyloP100

0.91

Sift4G

Benign

1.0

Vest4

0.11

gMVP

0.63

Mutation Taster

=100/0

polymorphism

(source)

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over