hi Professor and welcome. I presume your academic field is in the Arts. I would feel totally lost in sociology or economics for instance, if I had a personal and urgent reason to need to get my head around those fields.
Your best approach IMO is to educate yourself in the field of biology and biochemistry. You are still very young, apoe4 is a risk for LATE oneset Alzheimer's. You have at least a couple decades to learn, and to wait for advances of understanding and therapeutics in the field.
I wrote the Primer (and its associated glossary) for those like you - who need to start from scratch and feel overwhelmed. Start there, before you read Bredesen's book. It explains how DNA works as well.viewtopic.php?t=1418
Nobody can give you an accurate lifelong risk prediction. But your risk today, this year, even this decade, is no greater than someone who is not 4/4. Take your time to learn. It will take time. You have the time, you are not at risk today.