ch. 14.4. Autism spectrum disorders

Question 1

How can researchers determine whether a mutation or microdeletion has arisen anew?

Answer 1

They compare the child’s chromosome to those of the parents. If neither parent has that mutation or microdele- tion, then it arose anew. They can also examine surround- ing genes to determine whether the chromosome came from the father or the mother.

Question 2

Having a sibling with autism who is close to your age increases your own risk more than having a sibling with autism who is much older or younger. What conclusion does this observation imply?

Answer 2

Genetics cannot be the whole explanation for autism. Factors in the prenatal environment may contribute. The prenatal environment would be more similar for siblings close in age.

Question 3

In what way is the genetic basis of autism similar to that of schizophrenia?

Answer 3

In both, many genes contribute.

Question 4

What anatomic difference is common for children with autism compared to non-autistic children, at age one year?

Answer 4

The head is 10 percent larger than average.

Question 5

What dietary supplement during pregnancy decreases the probability of having a child with autism?

Answer 5

Folic acid