chr2-21029890-G-A

Variant names:

• chr2-21029890-G-A
• rs779326198
• NM_000384.3:c.1470+8C>T

Variant summary

Our verdict is Likely benign. The variant received -6 ACMG points: 0P and 6B. BP4_Strong BP6_Moderate

The NM_000384.3(APOB):​c.1470+8C>T variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000412 in 1,457,626 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Likely benign (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000041 (0 hom.)
• Consequence: APOB NM_000384.3 splice_region, intron
• Scores: Splicing: ADA: 0.00009398
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: -0.303
• Publications: 0 publications found

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

ACMG classification

Our verdict: Likely_benign. The variant received -6 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.81).
• BP6: Variant 2-21029890-G-A is Benign according to our data. Variant chr2-21029890-G-A is described in ClinVar as Likely_benign. ClinVar VariationId is 544109.Status of the report is criteria_provided_single_submitter, 1 stars.

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	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	APOB	NM_000384.3	MANE Select	c.1470+8C>T		splice_region intron	N/A	NP_000375.3

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	APOB	ENST00000233242.5	TSL:1 MANE Select	c.1470+8C>T		splice_region intron	N/A	ENSP00000233242.1
	APOB	ENST00000399256.4	TSL:1	c.1470+8C>T		splice_region intron	N/A	ENSP00000382200.4
	APOB	ENST00000673739.2		n.*776+8C>T		splice_region intron	N/A	ENSP00000501110.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.0000239 AC: 6 AN: 251172 AF XY: 0.00000737

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.000173

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000412 AC: 6 AN: 1457626 Hom.: 0 Cov.: 30 AF XY: 0.00000138 AC XY: 1 AN XY: 725402

African (AFR) AF: 0.00 AC: 0 AN: 33402

American (AMR) AF: 0.000134 AC: 6 AN: 44716

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26098

East Asian (EAS) AF: 0.00 AC: 0 AN: 39666

South Asian (SAS) AF: 0.00 AC: 0 AN: 86164

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53056

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5758

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1108500

Other (OTH) AF: 0.00 AC: 0 AN: 60266

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000151

ClinVar

ClinVar submissions as Germline

Significance: Likely benign

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	-	1	Hypercholesterolemia, autosomal dominant, type B;C4551990:Familial hypobetalipoproteinemia 1 (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.81
CADD	Benign	3.5
DANN	Benign	0.47
PhyloP100		-0.30

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.000094
dbscSNV1_RF	Benign	0.026
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

Other links and lift over

dbSNP: rs779326198; hg19: chr2-21252762;