tagged w/ Developmental Disability
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"Eileen Muniz of Mohegan Lake, N.Y., cannot imagine what bizarre twist of fate caused all three of her children to be afflicted with autism spectrum disorders. There's no family history of autism, she says. "You always ask yourself, Is it me? Is it him [her ex-husband]? I had my kids late — in my mid-30s. Was I on the birth control pill too long? I never did drugs. I don't smoke. I can't figure out why this would happen to us. That's why I wanted to do the genetic testing.
The study, published in the current issue of Nature, focused on a region of DNA that codes for two proteins called cadherin 9 and 10. These are sticky substances involved in a process known as neuronal cell adhesion. "They sit at the synapse, and when the nerves come together, these molecules adhere to the nerve," essentially fusing a connection in the brain, explains Dr. Hakon Harkonarson, director of the Center for Applied Genomics at the Children's Hospital of Philadelphia (CHOP) and a lead author of the study. Preliminary research suggests that cadherin 10 is very active in wiring the frontal cortex of the brain during fetal development.
A malfunction affecting one of these genes is not, in itself, enough to cause autism, the Icelandic researcher is quick to point out. It would take a combination of several genetic flaws and perhaps environmental factors as well for autism to emerge. "This gene is a key driver in causing autism in about 15% of cases," Harkonarson asserts.
Variations in these genes on chromosome 5 are extremely common — present in more than half of healthy people. But they are even more common in individuals with autism, affecting 65%. It takes enormous genomewide association studies like this one — what researchers call very "high powered" studies — to discern this kind of statistical difference.""Eileen Muniz of Mohegan Lake, N.Y., cannot imagine what bizarre twist of fate... more
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"As evidence of widespread vitamin D deficiency grows, some scientists are wondering whether the sunshine vitamin—once only considered important in bone health—may actually play a role in one of neurology's most vexing conditions: autism.
The idea, although not yet tested or widely held, comes out of preliminary studies in Sweden and Minnesota. Last summer, Swedish researchers published a study in Developmental Medicine and Child Neurology that found the prevalence of autism and related disorders was three to four times higher among Somali immigrants than non-Somalis in Stockholm. The study reviewed the records of 2,437 children, born between 1988 and 1998 in Stockholm, in response to parents and teachers who had raised concerns about whether children with a Somali background were overrepresented in the total group of children with autism.
In Sweden, the 15,000-strong Somali community calls autism "the Swedish disease," says Elisabeth Fernell, a researcher at the Karolinska Institute in Stockholm and a co-author of the study.
In Minnesota, where there are an estimated 60,000 Somali immigrants, the situation was quite similar: There, health officials noted reports of autism among Somali refugees, who began arriving in 1993, comparable to those found in Sweden. Within several years of arrival, dozens of the Somali families whose children were born in the U.S. found themselves grappling with autism, says Huda Farah, a Somali-born molecular biologist who works on refugee resettlement issues with Minnesota health officials. The number of Somali children in the city's autism programs jumped from zero in 1999 to 43 in 2007, says Ann Fox, director of special education programs for Minneapolis schools. The number of Somali-speaking children in the Minneapolis school district increased from 1,773 to 2,029 during the same period.
Few, if any, Somalis had ever seen anything like it. "It has shocked the community," Farah says. "We never saw such a disease in Somalia. We do not even have a word for it."
What seemed to link the two regions was the fact that Somalis were getting less sun than in their native country—and therefore less vitamin D. The vitamin is made by the skin during sun exposure, or ingested in a small number of foods. At northern latitudes in the summertime, light-skinned people produce about 1,000 international units (IUs) of vitamin D per minute, but those with darker skin synthesize it more slowly, says Adit Ginde, an assistant professor at the University of Colorado Denver School of Medicine. Ginde recommends between 1,000 to 2,000 IUs per day, calling current recommendations of 200 IUs per day outmoded."
A LOT more at link, what do YOU think?"As evidence of widespread vitamin D deficiency grows, some scientists are... more
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