rs1553384177

Positions:

• chr2-21013287-G-C
• chr2-21013287-G-T

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PVS1 PM2 PP5

The NM_000384.3(APOB):​c.4089C>G​(p.Tyr1363*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (no stars). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 33)
• Consequence: APOB NM_000384.3 stop_gained
• Clinical Significance: Pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 3.29

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]

ACMG classification

Verdict is Pathogenic. Variant got 11 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 2-21013287-G-C is Pathogenic according to our data. Variant chr2-21013287-G-C is described in ClinVar as [Pathogenic]. Clinvar id is 440525.Status of the report is no_assertion_criteria_provided, 0 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
APOB	NM_000384.3	c.4089C>G	p.Tyr1363*	stop_gained	25/29	ENST00000233242.5	NP_000375.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
APOB	ENST00000233242.5	c.4089C>G	p.Tyr1363*	stop_gained	25/29	1	NM_000384.3	ENSP00000233242.1
APOB	ENST00000673739.2	n.*3395C>G		non_coding_transcript_exon_variant	24/25			ENSP00000501110.2
APOB	ENST00000673739.2	n.*3395C>G		3_prime_UTR_variant	24/25			ENSP00000501110.2
APOB	ENST00000673882.2	n.*3184C>G		downstream_gene_variant				ENSP00000501253.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

Submissions by phenotype

Familial hypobetalipoproteinemia Pathogenic:1

Pathogenic, no assertion criteria provided

research

Laboratorium voor Moleculaire Diagnostiek Experimentele Vasculaire Geneeskunde, Academisch Medisch Centrum

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.52	D
BayesDel_noAF	Pathogenic	0.50
CADD	Pathogenic	37
DANN	Uncertain	1.0
Eigen	Pathogenic	0.76
Eigen_PC	Uncertain	0.58
FATHMM_MKL	Uncertain	0.93	D
Vest4		0.96
GERP RS		4.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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

Other links and lift over

dbSNP: rs1553384177; hg19: chr2-21236159;