Try taking a mesure instrument of any kind (like a ruler or measuring tape) and put it along your arm.
Prone. Most people are more genetically prone to have those diseases/disabilities because someone in their bloodline before them was also prone to them or constantly had troubles with those diseases/disabilities so they are far more likely to get/have them than people whose family didn't have them.
(I hope I explained that good enough for you).
3!! 1,2,4 counting by one’s counting by 2s and 4s
