According to Baltimore Sun, identical twins John and Sam Fetters could not speak a word at 22 months of age. At two years of age, doctors diagnosed both boys with autism. Their family wondered what could have caused autism in both twins and if perhaps, genetics could be responsible.
According to a study at Kennedy Krieger Institute, researches examined 277 pairs of twins and found that when one identical twin had the disorder, the other twin had an 88 percent chance of developing autism as well. Fraternal twins had a 31 percent chance of both having autism.
Autism is a neurological disorder that disrupts normal development and medical experts classify it as a pervasive developmental disorder. The cause of autism is unknown, although researchers and medical experts suspect everything from environmental toxins to medication introduced to women while pregnant as possible causes. Complicated births, such as those in multiple births, may contribute to autism, according to a Duke University study.
Multiple births increase the risk of an autism diagnosis. Multiple studies suggest identical twins have a 63-98% chance of both twins having autism, while fraternal or dizygotic twins having a 0-10% chance of both twins developing autism. Doctors see autism more often in boys, with four boys having autism compared to one girl and it is a disorder diagnosed within the first three years of life, according to the Centers for Disease Control and Prevention.
