Larger brains may be associated with regressive autism, but only in boys, according to a study published online 28 November in the Proceedings of the National Academy of Sciences.
A small fraction of young children with autism have low levels of folate, a B vitamin, in their cerebrospinal fluid, according to unpublished research presented at the 2011 Society for Neuroscience annual meeting in Washington, D.C.
Defects in a signaling pathway that regulates learning and memory could underlie regressive autism, a sudden loss of language or social ability.
Individuals who have autism and dysmorphology comprise a distinct subgroup within the disorder, says geneticist Judith Miles.
Autism is diagnosed based on the severity and variety of its symptoms. This makes it very difficult to diagnose and easy to confuse with other disorders, such as language delay and intellectual disability, cautions Isabelle Rapin.
Regression, a sudden loss of language and social ability, does not lead to more severe autism, according to a study published in March in the Journal of Autism and Developmental Disorders. The study suggests that how autism develops does not influence the long-term outcome of children with the disorder.
The first study to look at mitochondria — the powerhouses of the cell — in postmortem brain tissue taken from children with autism has found significant abnormalities in their function in some regions of the brain.
Toddlers who abruptly lose language, social or other developmental skills are more likely to have severe autism a few years later compared with children who have consistent delays from an early age. That’s the conclusion of the largest study thus far of autism onset patterns, published in the Journal of Autism and Developmental Disorders.