Which type of genetic disorder is autism?

Polygenic: Autism has several different brain pathologies. A few probable loci are known, and there may be environmental factors before or aftre birth even though the alleged link to vaccines was a proven fraud. In a polygenic disorder, several loci contribute to the final condition. Features of these disorders are variable severity, and the closer the relationship to the index patient the greater the risk.

Fragile X Syndrome &: > 30 other known genetic syndromes can cause autistic spectrum disorder & intellectual disability. Copy repeat errors on genetic microarray occur in another ~15% of folks with asd. Epigenetic factors (some viruses & toxins) change function, but not structure or sequence of fetal genes. The risk for siblings of kids with ASD of unknown etiology (cause) to develop signs of ASD is 20-40%.