The identity of ‘the grandfather’

The identity of ‘the grandfather’

The passage below is from Jellyfish age backwards by Nicklas Brendborg.

A study from Taiwan provides the main suspect. The Taiwanese researchers discovered that people infected with the herpes virus are two-and-a-half times more likely to get Alzheimer’s than those who aren’t –that is, unless they are taking anti-herpes medication. This medication suppresses the virus, and interestingly, it also brings the risk of Alzheimer’s back to normal. The case strengthens as several research groups have found traces of the herpes virus in brain tissue samples from deceased Alzheimer’s patients (while being absent from controls). In one study, the virus was even found inside the amyloid beta clumps in Alzheimer’s brains. Researchers can also duplicate the effect in the laboratory. If brain cells in culture are infected with herpes virus, amyloid beta clumps appear – unless anti-herpes medicine is also added. The connection could also explain a puzzling finding about the grandfather of the Alzheimer’s risk genes. We have previously encountered the APOE gene in which a specific genetic variant increases the risk of Alzheimer’s disease. It turns out the same genetic variant increases the risk of getting cold sores for people infected with the herpes virus. It could be that this particular genetic variant simply makes people worse at fighting herpes infections.

In the passage doe ‘the grandfather of the Alzheimer’s risk genes’ mean ‘the APOE gene’? Am I right?

Thanks in advance.