A US psychologist says she has identified five predictors of autism in infants.
The five predictors identified were - lack of response to others' attempts to engage the babies in play, infrequent attempts to initiate joint activities, few types of consonants produced when trying to communicate vocally, problems in responding to vocal requests and a keen interest in repetitive acts, such as staring at a toy while twirling it. In Ms Landa's investigation, the presence of all five behaviors at 14 months predicted an eventual diagnosis of autism spectrum disorder in 15 of 16 children.
Landa's study consists of 250 children who were first assessed at either age 6 months or 14 months. Comprehensive measures of social, communication and motor abilities were obtained at each child's home and repeated at 18, 24, 30 and 36 months of age. The sample included 110 children considered to be at high risk for developing autism because they had older siblings already diagnosed with the same condition.
Preliminary evidence suggests that high-risk 14-month-olds who later develop autism display signs of delayed motor development as early as 6 to 7 months of age, Landa noted. In particular, these youngsters had difficulty keeping their heads stable when slowly raised from a prone position, writes Bruce Bower in Science News.
But psychologists cautioned that much remains unknown about the early identification and treatment of autism. Infant siblings of older children with autism represent a special group that's especially likely to show early signs of the same disorder, they said.
"I'm not sure the majority of children with autism spectrum disorder have predictive symptoms by 12 or 14 months," said Sally Rogers of the University of California.
In her own long-term studies, some children without autistic siblings show a gradual slowing of social and language development over several years that leads to autism, while others show no autism symptoms at all until being diagnosed with the disorder at age 4 or 5.