Yes, autism, and ADHD, can run in families.
It is called "Autistic Spectrum Disorder" specifically because there is no "one size fits all" problem. There is a very wide range of ways a person can be affected.
Labels, like most anything else, can be either useful, or hurtful.
ADHD, and Autism, are not "labels". They are disorders, disabilities, illnesses.
Is it a "label" to say someone who can not hear is deaf, or hearing impaired?
I, personally, do not give a rat's hiney if folks "judge" me or not. That is THEIR problem, not MINE.