Expert: Trey McGowan - 6/29/2007

Question
I have three boys, one who is autistic and one who is ADHD, the third is 5 and as of now is normal, out of curiosity how common is it to have a situation like this.  Could i have a faulty gene or something im passing to my offspring?

Answer
Hi there, Margaret!

Genetic studies on autism running in families is still in the works. However, while there are not a lot of published studies, there is evidence to support that autism can be genetically passed along. It can also skip generations, the same as many genes can. There's not yet a study on exactly what genes make 'autism at birth' (or, for that matter, if they even truly do) so I can't help with giving exact answers on that part.

As for your three boys, ADHD is commonly diagnosed in autistics, as they have very similar effects and tend to be comorbid (both appearing in the same individual; many autistics have ADHD). Therefore, it's not a surprise to me that they're showing up in the same family even if your middle child(?) is 'only' ADHD. Likewise with the normal child showing signs of neither. It's that 'genetics' thing. Sometimes it hits the button, sometimes it doesn't. It's a little more complex than '1/4 of the time blue eyes breed true' since no one's sure if 'autism' is a single gene or not, but it is not at all uncommon to have an autistic in a family where others are not.

Whether you're passing it on or not, I'm going to have to make a guess with this and say that it depends on a lot of things. For one, do they all have the same father? If so, then it could be simply a matter of 'two recessives making a dominant'. If not, then compare the children (or child) of one father and it may well be that the two genes are crossing 'badly' there. Also, take a moment and consider yourself. Do you (or their father) show traits that lean toward the autistic spectrum? Even if you are not diagnosed (or even not autistic!) if you happen to have the mild traits, it's very possible that you simply happened to 'combine' them and pass them along. My mother has some of the traits. My father has others. Neither are autistic and yet they produced a 'purebred Aspergers'. Sometimes it just happens.

And finally, the term 'faulty gene' I find to be an awkward one. It's very likely not that the gene is faulty. It is simply altered from what someone would call 'usual', or there are a specific group of genes that happen to conform into 'autism'. Yes, there is the possibility that somewhere you have a genetic propensity to give birth to autistic/ADHD children. However, this does not make you in the least bit 'faulty'. It just means that you happen to be like everyone else in the world: a mix of genes that sometimes don't come together in the way everyone would think is 'perfect'. If you feel truly upset about it, see if there is a genetic counselor or therapist in your area to speak to. They may be just what you need if you're feeling uncomfortable about it. Or maybe I'm just reading too much into the choice of words with 'faulty'. I do that. :)

Best regards,

Trey