SAN FRANCISCO, Feb. 18 (Xinhua) -- Researchers studying the brains of infants who have older siblings with autism were able to identify 80 percent of the babies who would be subsequently diagnosed with autism at 2 years of age.
The results, published this week in the journal Nature, stem from research led by the University of North Carolina to use magnetic resonance imaging (MRI) to measure the brains of "low-risk" infants, with no family history of autism, and "high-risk" infants who had at least one autistic older sibling.
A computer algorithm was then used to predict autism before clinically diagnosable behaviors set in, subsequently making it the first study to show that it is possible to use brain biomarkers to identify which infants in a high-risk pool, namely those having an older sibling with autism, will be diagnosed with autism spectrum disorder, or ASD, at 24 months of age.
"Typically, the earliest we can reliably diagnose autism in a child is age 2, when there are consistent behavioral symptoms, and due to health access disparities the average age of diagnosis in the U.S. is actually age 4," said co-author and University of Washington (UW) professor of speech and hearing sciences Annette Estes. "But in our study, brain imaging biomarkers at 6 and 12 months were able to identify babies who would be later diagnosed with ASD."
While researchers at four clinical sites in the United States took part, the project included hundreds of children across the country.
The researchers obtained MRI scans of children while they were sleeping at 6, 12 and 24 months of age, and assessed the babies' behavior and intellectual ability at each visit. They found that the babies who developed autism experienced a hyper-expansion of brain surface area from 6 to 12 months, as compared to babies who had an older sibling with autism but did not themselves show evidence of autism at 24 months of age. Increased surface area growth rate in the first year of life was linked to increased growth rate of brain volume in the second year of life. Brain overgrowth was tied to the emergence of autistic social deficits in the second year.
By inputting these data, including MRI calculations of brain volume, surface area, and cortical thickness at 6 and 12 months of age, into a computer program, the researchers sought to classify babies most likely to meet ASD criteria at 24 months of age. They found that, among infants with an older ASD sibling, the brain differences at 6 and 12 months of age successfully identified 80 percent of those infants who would be clinically diagnosed with autism at 24 months of age.
The predictive power of the findings may lead to a diagnostic tool for ASD that could be used in the first year of life, before behavioral symptoms have emerged.
"We don't have such a tool yet," Estes was quoted as saying in a news release from UW. "But if we did, parents of high-risk infants wouldn't need to wait for a diagnosis of ASD at 2, 3 or even 4 years and researchers could start developing interventions to prevent these children from falling behind in social and communication skills ... By the time ASD is diagnosed at 2 to 4 years, often children have already fallen behind their peers in terms of social skills, communication and language."
体坛资讯:Nadal bags French Open hat-trick
体坛资讯:China race into Sudirman Cup final
托福口语中的20个否定句例子
2017年托福考试时间表
四级听力技巧之把握条件句
国际英语资讯:Virus strain discovered in Australia could cause worldwide gastroenteritis outbreak
省时省力的居家清洁小妙招
体坛资讯:China win sixth Sudirman Cup title
体坛资讯:China storm into semis, S. Korea pose strong in Sudirman Cup
体坛资讯:Runners get compensation from coach
国内英语资讯:Chinese economy is stable: central bank official
英语六级作文三大定律
如何用好托福机经
国内英语资讯:Chinese naval fleet visits Malaysia to enhance military ties
英文歌曲之Your firefly
国内英语资讯:Chinese FM meets Peruvian president on bilateral ties, free trade
老外是如何说“怂”的!
生活中的美 Beauty in Life
国内英语资讯:Chinese premier to meet leaders of Portuguese-speaking countries in Macao
体坛资讯:Yi among few global prospects to stay in NBA Draft pool