NM_000384.3:c.13480_13482delCAG
Variant summary
Our verdict is Uncertain significance. The variant received 1 ACMG points: 1P and 0B. PM4_Supporting
The NM_000384.3(APOB):c.13480_13482delCAG(p.Gln4494del) variant causes a conservative inframe deletion change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000364 in 1,614,014 control chromosomes in the GnomAD database, including 1 homozygotes. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_000384.3 conservative_inframe_deletion
Scores
Clinical Significance
Conservation
Publications
- hypercholesterolemia, autosomal dominant, type BInheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, G2P, Labcorp Genetics (formerly Invitae), ClinGen, Ambry Genetics
- familial hypobetalipoproteinemia 1Inheritance: AR, AD, SD Classification: DEFINITIVE, STRONG Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae), Genomics England PanelApp, ClinGen
- homozygous familial hypercholesterolemiaInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Uncertain_significance. The variant received 1 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| APOB | NM_000384.3 | c.13480_13482delCAG | p.Gln4494del | conservative_inframe_deletion | Exon 29 of 29 | ENST00000233242.5 | NP_000375.3 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| APOB | ENST00000233242.5 | c.13480_13482delCAG | p.Gln4494del | conservative_inframe_deletion | Exon 29 of 29 | 1 | NM_000384.3 | ENSP00000233242.1 |
Frequencies
GnomAD3 genomes AF: 0.000217 AC: 33AN: 152138Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.000384 AC: 96AN: 250322 AF XY: 0.000391 show subpopulations
GnomAD4 exome AF: 0.000380 AC: 555AN: 1461758Hom.: 1 AF XY: 0.000338 AC XY: 246AN XY: 727184 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.000217 AC: 33AN: 152256Hom.: 0 Cov.: 32 AF XY: 0.000215 AC XY: 16AN XY: 74450 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Hypercholesterolemia, autosomal dominant, type B Pathogenic:3Uncertain:1
Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as VUS-3B. Following criteria are met: 0102 - Loss of function is a known mechanism of disease in this gene and is associated with familial hypercholesterolaemia, 2 (MIM#144010) and hypobetalipoproteinaemia (MIM#615558). (I) 0108 - This gene is associated with both recessive and dominant disease. Familial hypercholesterolaemia 2 (MIM#144010) is inherited in an autosomal dominant manner, whereas hypobetalipoproteinaemia (MIM#615558) is recessive (OMIM). (I) 0112 - The condition associated with this gene has incomplete penetrance (GeneReviews). (I) 0216 - In-frame insertion/deletion in a non-repetitive region that has low conservation. (SP) 0251 - This variant is heterozygous. (I) 0302 - Variant is present in gnomAD (v2) <0.001 (104 heterozygotes, 0 homozygotes). (SP) 0600 - Variant is located in the annotated ApoB100_C domain (DECIPHER). (I) 0808 - Previous reports of pathogenicity for this variant are conflicting. This variant has been reported once as likely benign, but moreso as likely pathogenic, pathogenic or as a VUS (ClinVar, LOVD). It has been observed in at least four unrelated heterozygous individuals with familial hypercholesterolaemia, where two had additional pathogenic variants in the PCSK9 gene or the APOB gene. In one family, the variant only partially segregated with disease (PMID: 33269076, PMID: 26643808, PMID: 24234650, PMID: 33418990, PMID: 18710658). (I) 1002 - This variant has moderate functional evidence supporting abnormal protein function. Analysis of patient-derived protein and transfected cells demonstrated reduced LDLR binding capacity, LDL uptake and U937 cell proliferation (PMID: 26643808, PMID: 24234650). (SP) 1208 - Inheritance information for this variant is not currently available in this individual. (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -
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ACMG Criteria: PP5, PM4, PS3; Variant was found in heterozygous state -
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Hypercholesterolemia, familial, 1 Pathogenic:2Uncertain:1
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0/192 non-FH alleles -
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not provided Uncertain:2
Published functional studies demonstrate a damaging effect through a 40% decrease in internalization in lymphocytes and HepG2 cells (Alves et al., 2014); In silico analysis supports a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 26643808, 24234650, 32719484, 32770674, 33269076, 33418990, 33303402, 35913489, 31980526) -
The APOB c.13480_13482del (p.Gln4494del) variant has been reported in the published literature in individuals affected with hypercholesterolemia (PMIDs: 31980526 (2020), 32770674 (2020), 33269076 (2021), 33303402 (2021), 33418990 (2021), and 35913489 (2022)), and did not fully co-segregate in one family (PMID: 24234650 (2014)). Additionally, functional studies have shown this variant caused impaired LDL binding and uptake (PMIDs: 24234650 (2014) and 26643808 (2015)). The frequency of this variant in the general population, 0.0007 (90/128394 chromosomes in European (Non-Finnish) subpopulation (Genome Aggregation Database, http://gnomad.broadinstitute.org)), is higher than would generally be expected for pathogenic variants in this gene. ClinVar contains an entry for this variant (URL: www.ncbi.nlm.nih.gov/clinvar, Variation ID: 265896). Based on the available information, we are unable to determine the clinical significance of this variant. -
Hypercholesterolemia, autosomal dominant, type B;C4551990:Familial hypobetalipoproteinemia 1 Uncertain:1Benign:1
The p.Gln4494del variant in APOB gene has been previously reported in at least 4 unrelated individuals affected with familial hypercholesterolemia (Alves et al., 2014; Rieck et al., 2020; Miroshnikova et al., 2021). This variant did not completely segregate with disease in one family (Alves et al., 2014). This variant has been identified in 90/128,394 European non-Finnish chromosomes (104/281,716 chromosomes overall) by the Genome Aggregation Database (http://gnomad.broadinstitute.org/). This variant has been observed in the population at a frequency higher than expected for a potentially disease-causing variant. The p.Gln4494del variant results in an in-frame deletion of 1 amino acid in exon 29 of the APOB gene. Computational tools predict that this variant is deleterious; however, the accuracy of in silico algorithms is limited. Functional studies of this variant demonstrated a reduction in the binding and uptake of LDL and a change to the secondary structure of the ApoB100 protein (Alves et al., 2014; Fernández-Higuero et al., 2015). These data were assessed using the ACMG/AMP variant interpretation guidelines. In summary, despite some supporting functional evidence the significance of the p.Gln4494del variant is uncertain due to limited case data and population frequency data. Additional information is needed to resolve the significance of this variant. [ACMG evidence codes used: BS1; PS3_Moderate; PP3] -
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not specified Uncertain:1
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Cardiovascular phenotype Benign:1
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. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at