ApoE genotyping
| Category | Specialist Integrated Haematological Malignancy Diagnostic Service (SIHMDS) >> Molecular Pathology |
|---|---|
| Test background |
Apolipoprotein E (ApoE) has a pivotal role in the metabolism of VLDL-cholesterol, and HDL-cholesterol, and as a ligand, it binds both LDL-cholesterol and ApoE receptors. The APOE gene is located on chromosome 19q13.2 and has 3 main allelic variants: ε3, ε4, andε2. ε3 is the most common, followed by ε4 and ε2. These 3 allelic variants differ at 2 single-base variations located in exon 4 at codon positions 130 and 176 (Historically described as positions 112 and 158). The single nucleotide changes of APOE c.388T>C p.(Cys130Arg) (112T>C) (SNP: rs429358) and APOE c.526C>T p.(Arg176Cys) (158C>T) (SNP: rs7412) encode Cys and Arg, respectively. ε2 has a T at both positions 112 and 158; ε3 has one T and one C at either position 112 and 158;and ε4 has a C at both positions. These isoforms have been widely studied as possible risk factors for coronary heart disease, type III hyperlipoproteinaemia and strokes. A real time fluorescence PCR genotyping assay is used to determine the presence of the APOE 112T>C and 158C>T variants and haplotype. |
| Clinical Indications |
For prognostic testing in coronary heart disease, type III hyperlipoproteinaemia and strokes. |
| Sample & container required | 4ml Peripheral Blood in EDTA (lavender/purple top) |
| Turnaround time | 14 calendar days |
| Notes | The laboratory is not UKAS accredited for this test. |