{{Rsnum
|rsid=527236160
}}

Also known as c.291del or p.E97fs, this rare SNP in the [[APOE]] gene was found by whole-exome sequencing of the DNA of a patient with severe dysbetalipoproteinemia., The patient was homozygous for the minor/rare allele, rs527236160(-;-), yet despite the complete absence of apoE, he had "normal vision, exhibited normal cognitive, neurological, and retinal function, had normal findings on brain magnetic resonance imaging, and had normal cerebrospinal fluid levels of β-amyloid and tau proteins". He did have extremely high cholesterol levels (760 mg/dL) and mild atherosclerosis but otherwise no significant symptoms of cardiovascular disease. Overall, it appears as if apoE is not essential in the brain or eye.{{PMID|25111166}}