Infants at Risk for Autism: A longitudinal study

Autism rates have been increasing in the US and abroad. With this rise, comes concern for recurrence rates in families. Previous recurrence rates for siblings with autism were estimated at about 3-10%. Also, the average age for when children are diagnosed with autism is around four years of age. However, many parents can see signs much earlier. Therefore, the purpose of this study was to determine if siblings have a higher risk of autism or other developmental problems and determine the earliest signs for diagnosing autism. Two phases were conducted over seven years. The first phase compared children with autism to those of children with typical development in areas such as communication, emotion and imitation. The research found that the earliest signs of autism begin appearing around 12 months of age. These red flags are failure to respond to his or her name and repetitive behaviors especially when playing with toys. In the second phase, participants included infants nine months or younger with a sibling with typical development or autism. The infants were given developmental tests using the Mullen and ADOS at 6, 9, 12, 15, 18, 24 and 36 months. Parent questionnaires such as the Vineland II and Social Responsiveness Scale were used to aid in a correct diagnosis. From this, the new estimated recurrence rate is about 18.7 %. Also, the study presented data that determined that the gender of the infant and presence of a multiplex family also plays a role and dramatically increases the recurrence rate.