Dear colleagues, 

I do not agree with this phrase "'genes load the gun, but the environment pulls the trigger". I agree with Anthony G. Gordon. We also know that ASD, ADHD have many similaritlities in  behavioural level.   There are abnormalities in the chromosomes  1,2,3,4,6,13 and 15. Many surveys  proving that there are abnormalities in chromosomes 2,3,6 and 15. Many individuals with ASD meet the criteria to be diagnosed with Dyslexia and vice versa. Also, many individuals with ADHD meet the criteria to be diagnosed with Dyslexia and vice versa.  See more in my PDF

ASD and  ADHD ,are two different disorders  though they can coexist , with ASD being congenital and more expressive even during the stage of infancy and ADHD being more expressive in the later years of childhood and teenage years.  they do share certain common features such as exceptional abilities in possessing very sharp Eidetic memory.1 ,2 ,4 and  7 (categories of learning disabilities as stated in the question)may be absent with  ADHD . Again that depends on the onset and the age at which ADHD becomes more expressive or pronounced .As a practitioner , I have seen ASD in a more severe  form and ADHD more active though ASD is more controlled at a later age but  ADHD benefiting  more from learning situtations

The whole series of questions about "individuals" and "people" "sharing" or "having similar" disorders/diagnoses, and the attachment ('similarities' chart) uses a lot of terms that I find too imprecise to lead to good conclusions. There is a significant mathematical/statistical component to some of the questions you seem to have, but I am not sure exactly what you are asking and whether you are asking about probabilities or population rates. All of the answers that get to specific reasons for similarities and differences (genetics, environment, epi-genetics, etc.) aren't going to help without knowing what level of study you are interested in.  

Pretty much all of what you seem to be interested in are various neuro-developmental disorders. By definition, there are brain differences between individuals with these disorders and those with  "normal" brain development. EVERY individual will have a unique combination of measurable symptoms and could be 'similar' to another with respect to some symptoms and not similar on others. An individual may or may not share enough similarities to both fit into the same diagnostic category. So please can you explain your chart and conclusion? I can't understand why you say "Yes" in many of the cells? What is the "question" to which you are answering "Yes"?

If the question is merely "can they co-exist" then you should change the one "NO" to a  "YES". And if the question is "are they similar?" then you need to define or at least quantify what you mean by "similar". Otherwise, just 'informally', if the question is "are they similar" I would say many of your "yes'" answers are incorrect.  

It looks to me as though the conclusion does not logically (or empirically) arise from data about these disorders and could lead to some very unfortunate decisions if used in a clinical or special education settings.  What do you mean by "a sufficient percentage" of children? (There may be some issues here with usage of that term, but I'm not clear about what you are saying. Sorry).  It seems to imply that ADHD is causing under-diagnosis of ASD? Is that what you mean? I am very concerned when special education people, without diagnostic expertise get confused by information that may apply to diagnostic categories, but not necessarily individuals, or vice verse.