UC Davis researchers find California autism clusters, but the cause is a bit of a surprise

UC Davis researchers searching for autism clusters in hopes of finding an environmental cause for the disorder have identified 10 clusters around the state, but the source of the clusters is not exactly what they expected. The clusters, including five in metropolitan Los Angeles and one in San Diego, are centered on regional developmental services centers in areas with highly educated parents, primarily Caucasians, with high incomes. In short, what they found were clusters of increased diagnostic rates for autism. In one respect, the results were not surprising because it has long been known that high-income, highly educated white parents are more likely to have their children diagnosed with autism and more likely to have them diagnosed at an early age.

"Looking at clustering is often a way to uncover leads about problems in the environment," said epidemiologist Irva Hertz-Picciotto, the senior author of the study. "Mapping has a long history of being a way to get clues" about causes of disease. She was, indeed, surprised by the findings -- "not that there are clusters with parents with higher education, but that it was so consistent across the board." In virtually every cluster they identified, the rate of autism was about twice as high within the cluster as in adjacent regions.

Hertz-Picciotto and her colleagues obtained birth records for 2,453,717 children born in the state between 1996 and 2000. By 2006, the children had all reached at least age 6, the age by which diagnosis of autism is generally accomplished. State records showed that about 9,900 autism cases were in the records of the Department of Developmental Services. The team reported in the journal Autism Research that they identified 10 clusters of autism among the 21 regional offices of the department and two potential clusters. The clusters were primarily in the high-population areas of Southern California and, to a lesser extent, in the San Francisco Bay area.

The clusters were:

-- The Westside Regional Center in Culver City, which serves western Los Angeles County, including Culver City, Inglewood and Santa Monica.

-- The Harbor Regional Center, headquartered in Torrance, which serves southern Los Angeles County.

-- The North Los Angeles County Regional Center, in Van Nuys, which serves the San Fernando and Antelope valleys. Two clusters were in this region.

-- The South Central Regional Center in Los Angeles, which serves Compton and Gardena.

-- The Regional Center of Orange County in Santa Ana.

--The Regional Center of San Diego County, which serves San Diego and Imperial counties.

-- The Golden Gate Regional Center in San Francisco, which serves San Francisco, Marin and San Mateo counties. There are two clusters in this area.

-- The San Andreas Regional Center in Campbell, which serves Santa Clara, Santa Cruz, Monterey and San Benito counties.

Increased incidence was also noted in two other regions, the Central Valley Regional Center in Stockton and the Valley Mountain Regional Center in Fresno. The incidence of autism was not as high in those regions, however.

Because the team analyzed birth locations and not the location of diagnosis, it is highly unlikely that the parents moved into the cluster regions to seek care, Hertz-Picciotto said.

"In the U.S., the children of older, white and highly educated parents are more likely to receive a diagnosis of autism or autism spectrum disorder," said lead author Karla C. Van Meter, who was a graduate student when the data were collected but is now at the Sonoma County Department of Public Health. "For this reason, the clusters we found are probably not a result of a common environmental exposure. Instead, the differences in education, age and ethnicity of parents comparing births in the cluster versus those outside the cluster were striking enough to explain the clusters."

The team is now looking elsewhere for possible causes. Some previous studies have hinted that exposure to pesticides may play a role and a study in Texas showed that exposure to mercury in the environment --but not in vaccines -- could be a causative agent. "We are casting a wide net, looking at everything we can--pesticides, medical conditions in the mother, medications, flame retardants, etc.," Hertz-Picciotto said. The problem, she conceded, is that, if the exposure is truly widespread, then linking it to autism will be very difficult.

-- Thomas H. Maugh II

Credit: UC Davis M.I.N.D. Institute

Comments

[Tom]

Just to add to the mix: A study of 14,000 British children who are part of the ALSPAC cohort that were born in 1990-1991 found the following:

Children who had parents between the ages of 30 and 34 had statistically significant higher rates of Autism than parents who were 35 and old or 29 and younger.

Here's the name of the study: "Prevalence and characteristics of autistic spectrum disorders in the ALSPAC cohort"

The fact that Autism is increasing at such an exponential rate cannot be explained by the gradual increase in parental age. Nor can it be explained by vaccines or air pollutants.

It's also obviously not genetic unless you are small brained and believe that somehow in the 1990's a huge genetic mutation took over the human race.

It's obviously another environmental factor that neither the public nor scientists are focusing on. But, when they find it and the light bulbs go off I'm sure it will seem obvious.

[El Es Jardine]

A good argument for why equal access to health care for everyone could help everyone. But, then, maybe there is something that well educated people do, don't do, expose themselves to in some belief they're doing themselves and their offspring good that less well educated parents don't do or do? Or maybe the diagnoses are being too finely drawn, what's the flat-out incidence of old fashioned "retardation" in all cohorts?

[Tom]

El Es Jardine wrote:
"But, then, maybe there is something that well educated people do, don't do, expose themselves to in some belief they're doing themselves and their offspring good that less well educated parents don't do or do?"

Absolutely Great Point! I really think that all of this money spent on looking at vaccines, genetics, or pollutants might just be missing the point. It may be something as simple as some behavior that educated parents have a belief in that uneducated parents don't do. Considering the autism epidemic started in the 1990's it's likely this belief also began in the 1990's. Thanks again for a great observation.

El Es Jarine wrote:
"Or maybe the diagnoses are being too finely drawn, what's the flat-out incidence of old fashioned "retardation" in all cohorts?"

There has actually been numerous studies that show that there is an actual increase in autism. Although some of it may be due to more awareness the general consensus in the scientific community with expertise in Autism think there is an actual very large increase in autism rates since the 1990's.

[Heather]

OK, parents. If you don't want your kids to be autistic, go ahead and get them the vaccines. But quit your job and give away your money. Better yet, have your child raised by a family of color with modest means.

Has anyone thought that part of this is related to the unrealistic expectations wealthy, well-educated parents have of their children? If little Johnny is not reading Shakespeare by age 3, then there must be something wrong with him -- maybe it's autism? Because if your child is average, or below average, maybe you're not as smart as you think you are either.

I don't want to minimize the severity of autism, or the grief that it causes families -- regardless of color or income. But it seems likely that in at least some of these cases, children with relatively minimal symptoms but average to below-average academic achievement are identified as having autism-spectrum disorders (Asperger's?) in order to qualify them to receive special consideration.

Thus we throw a lot of tax dollars at children from wealthy families to compensate for the misfortune of having "only" average intelligence.

Good plan.

[James Michael Howard]

Possible Explanation of:

Autism Research 2010: Geographic distribution of
autism in California: a retrospective birth cohort analysis

Copyright 2010, James Michael Howard, Fayetteville, Arkansas, U.S.A.

I suggest that increased maternal testosterone produces autism in offspring.
There is research which suggests this possibility. It is also my hypothesis
that the "secular trend," the increase in size and earlier puberty occurring
in children, is caused by an increase in the percentage of individuals of
higher testosterone. More specifically, I suggest this is due to an increase
in the percentage of mothers of higher testosterone with time within the
population. This exposes more fetuses to increased maternal testosterone
with time within the population. I suggest this is the cause of the parallel
increase in morbidity occurring within the population, such as obesity,
cancer and breast cancer, diabetes, etc. This may explain why autism is
increasing.

Black, maternal testosterone is higher than white. One might expect,
therefore, that black women would produce more autistic offspring. The
explanation is that they produce excess testosterone that does not allow an
autistic individual to be born. Support is in the fact that black women
produce more low birth weight, premature, and small for gestational age
offspring than whites. Their "share" of autistic children are either hidden
within this group or they are simply aborted.

It is a proven fact that women of higher testosterone are more intelligent
and they are increasing
(http://www.anthropogeny.com/Secular%20Trend,%20Women%20and%20the%20Future.htm
). If you will read this, you will see that the same phenomenon, the
secular trend, is increasing the percentage of women of higher intelligence.
That is, this is occurring among a group of women of lower testosterone;
they have not become excessive in testosterone levels. This group is white
women. Since education may be interrupted by excessive testosterone, I
suggest women of lower socioeconomic levels are higher testosterone
producers. Lack of education segregates these women from areas where women
of higher education exist.

I suggest this group of women are reaching levels of testosterone that are
negatively affecting their offspring; this group of highly educated women is
increasing and increasingly producing autistic offspring.

[holly]

could it be that higher income people eat more fruits and vegetables perhaps from pesticides on them? just a thought.

[James]

I think the issue is with the diagnosis, not the disease. Sometimes a parent can overthink what it takes to be a parent! By no means am I advocating that just any person it cut out to raise a child - but children are not porcelain dolls. They can take a little roughhousing with siblings or friends, they can learn to deal with a bully (to a certain point), and believe it or not they can get dirty! They need freedom as well as structure in their life.

To many suburban parents planning their "playdates" in padded rooms. You will be shocked what your child can figure out on their own if you give them a chance!

[Brian]

There may be a more mundane explanation for these clusters. I wonder if they controlled for the diagnoser. It's well known among doctors that certain pediatric practices and doctors pulled the trigger on the autism diagnosis more than others.

I have a close friend who says that some parents get angry with him when he refuses to certify their child as autistic, and take them away to another nearby practice where the doctors are more accommodating. Remember, there is no test for autism, it's a subjective diagnosis based on certain criteria. What I may see may be different from what another doctor sees.

[Julia]

The advanced maternal age + testosterone theory sounds fishy (at least the person who wrote it did -- talking about "proven" causes, etc.)

Howevever advanced PATERNAL age has been found to be correlated to autism. The older the father, the greater chance of autism in the offspring. Older fathers have also been linked to higher incidence of schizophrenia, bipolar syndrome, and many types of genetic defects.

There is a theory that excessive folic acid supplementation may cause genes to "turn off" and "turn on" (by donating methyl groups), which might cause autism. NOT a reason to forgo the folic acid supplementation, though, because it definitely PREVENTS other defects.

More educated parents are probably more likely to take extra folic acid.

[Denise]

People who are commenting that the noted clusters amongst white, educated, higher income families must be related to parents with unrealistic expectations of their children's development and acheivement (e.g. Shakespeare by 3" comment, or "overprotective" parents keeping their child in a playdate bubble comment) are by inference then saying that the multiple professionals required to assess the child and provide the diagnosis of ASD must all be incompetent or else complicit in providing inaccurate diagnoses to please the parents??? Parents are not diagnosing their children.

As for the subjective nature of the evaluation and diagnosis, it is a true limitation - but it cuts both ways. As many children are under-diagnosed as are over-diagnosed, particularly if the requirement for official diagnosis lies in the hands of a single individual. Many "best practice" methods and requirements for diagnosis set the standard that a multidisciplinary team is needed to assess and concur on the diagnosis (namely, a developmental pediatrician, a developmental psychologist, and a speech-language pathologist - some add an occupational therapist). The thought being that this will increases the likelihood of accurate diagnoses.

[kibitzer]

Tom:
"...the general consensus in the scientific community with expertise in Autism think there is an actual very large increase in autism rates since the 1990's." Interesting point. Mark Blaxill (of SafeMinds & Age of Autism) has pointed out that a key time to investigate autism rates would be in those children born in or before 1989 and those from 1991. Reason? The vax schedule was increased considerably in '90-'91 w/the addition of the Hib and esp. the HepB (the latter shot given, God help us, at birth; far too soon for the developing neural system for something causing an inflammatory reaction). A study he found out of New Jersey showed 0 cases of ASD born in '88 or '89, and 1 in 128 born in 1993 plus.

This is also interesting because New Jersey has demonstrated some hot spots, relative to a lot of chemical/pharmaceutical companies. This particular study didn't look at that, was independent of that very possible factor in all this. Very possible, especially in the light of the findings of Dan Olmsted, former UPI reporter/investigator (& now associated w/AoA), in researching the case histories of the first families in the classic Kanner study, that a number of them had backgrounds with either mercury in fungicides or as farmers using such chemicals; many were also "college-educated and career-oriented...highly intelligent". The latter were the first families to pick up on the new-fangled medical modality of vaccines (before the ASD incidence started passing out into the populace at large, w/the advent of mass vaccination programs).

Interesting, that we seem to have come to a sort of full circle...I would tend to concur w/those who think this current clustering is due to the well-educated parents standing up more for their kids. But it's obvious that there's both an intellectual effect and a chemical-exposure effect in this sad chapter in our history; and so there could well be some toxic background to those cluster areas. As some families have discovered, when researching their medical problems, and discovering toxic water and such in their growing-up environments.

The researchers in CA should take case histories, and interview the parents, about their take on the matter; not just hope dry statistics will tell them much.

[Maddy]

New studies are always welcomed, especially when they're conducted by professionals.

The fact that M.I.N.D.'s study raises so many interesting issues is all the more reason to help fund further studies.

[A. Higgins]

As an Angeleno, I'd like to point out that Compton is not exactly a bastion of white upper class parents. I'm betting that the regional centers are centrally located, along with the hospitals that happen to have maternity wards and are network providers for Blue Cross/Blue Shield/Kaiser. The Westside regional center is a stone's throw from St. John's and UCLA Santa Monica. People drive there from farther away to give birth; the researchers have made a false assumption that people are going to have babies in hospitals closest to their homes, which is not necessarily true in this town. Also, upper class whites are more likely to have better medical coverage and therefore give birth in a hospital located near a regional center rather than at home. They also would tend to have more complete vaccinations than poorer communities, undocumented immigrants, or those with a reported cultural aversion to vaccines. Checking location of residence -- where the kids are growing up -- rather than of where they spend their first few days is more likely to yield meaningful environmental clusters; checking vaccination records would likely be even more fruitful.

[Shannon]

It's the vaccines. There were a lot of new vaccines added to the recommended schedule for infants at exactly the same time that autism rates jumped.

Most kids get vaccines but not everyone has autism because some kids are more susceptible to vaccine injury than others, due to genetic predisposition, underlying bacterial or viral infections, or higher exposure to environmental pollutants, including maternal amalgams and fish consumption. Often it's a combination of all those things. But if it weren't for the vaccines, the kids probably would have been okay.

My kids were born with a serious underlying bacterial infection (Lyme disease). But they are okay because they were never vaccinated.

[Heather]

Regarding being professionals being complicit with parents to stretch diagnostic criteria to get their children special treatment: I am not just implying it, I am saying it outright. As much as we would like doctors to be saints in scrubs, they are as fallible as anyone else. Can anyone say Nadya Suleman? Some doctors will do anything. Wealthy parents with good insurance are more likely to be able to doctor-shop for a diagnosis than are families with limited means. It is also not uncommon for a patient to come to a doctor with a diagnosis already in mind; if the physician does not confirm it, they look for another physician.

[Shannon]

Heather, once a child is diagnosed with autism, insurance denies most medical treatments, and most doctors ignore medical problems, blaming everything on autism. Why in the world would a parent try to fraudulently get an autism diagnosis?

[Mary]

Okay, if it's not the vaccines, then why don't we have that info in this "cluster study?" Why aren't they saying "this many children in the study were vaccinated and this many were not and this many were only vaccinated with some vaccines."

They don't say it because it is that simple and that obvious, it's the vaccines. Period. I love the other "ideas" that parenting could lead to such numbers. That's right up there with the article that ran in Scientific American that claimed that TV was causing autism. Too funny.

Want to cull your child from society, keep believing in vaccines and keep feeding them the crap that society calls food.

[di]

People who suspect their toddler may have autism or another developmental problem often move to school districts that are known to have good services. Did they figure that in?

[Heather]

Shannon, I am not suggesting that parents fraudulently try to get an autism diagnosis -- I believe that parents are well-intentioned and have concerns, and that they may latch onto autism as an answer. As for why they would want such a diagnosis, mental health parity requires that autism diagnoses be treated on equal par with other medical problems. Granted, the issue of whether ABA is a medical treatment is up in the air, but it seems likely that insurance will be required to pay for it. In addition, there are services provided by developmental centers and special services provided through school districts. For less affluent parents, there is the fact that the government provides SSI payments for disabled individuals. I am not aware of any treatments for physical diseases that would be denied to children with autism -- could you give some examples?

[Chris]

Look at the maps - Major highways pass through all the maps. Maybe the high concentration of heavy metals from diesel exhaust might play a role. I am sure others factors play into the equations.

[Dennis]

Getting a diagnoses for autism spectrum disorder is not simply a matter of not doing well in school or reading Shakespeare by 3. Your child has to be behind in 2 or 3 different areas (gross motor skill, communication, and socialization). So if you think the wealthy are looking for a diagnoses for autism just to gain an advantage for their child then you are wrong. Their is a big disconnect between a parent and a child with ASD. It's almost like your child does not love you and ignores you. Can you imagine how hard that is for a parent? In fact, the services are used just to get your child to a normal level. It will never get them academically ahead of the normal child.

I can understand how non-wealthy parents don't get a diagnoses for their child. They are constantly being told by other adults that their child is a little behind and will catch up. If you have more children, the ASD child gets lost in the group until she gets older. Those who have Asperger's are generally diagnosed later because they can talk, but if you see how they communicate, you notice they are continually on broadcast mode, and don't understand non-verbal communication (things a 1 year old has already mastered).

[Maureen Fischer]

Not surprising to those of us who are aware that the cause of autism is vaccinations. Highly educated and wealthy people tend to see to these things. Whereas I have read that inner city Detroit does not have a high autsim rate at all. Makes sense

[Kat]

Shannon wrote: "My kids were born with a serious underlying bacterial infection (Lyme disease). But they are okay because they were never vaccinated."...

That's so interesting! My kids were also born with Lyme but did have all their shots...although I'm questioning giving them anymore shots now that they have started treatment. One thing we always have done is eat wholesome organic foods. One thing I do know is that we are ALL bio-individuals with different triggers. Pesticides may set off one kid while another is set off by mercury in fish.

We are all so different and there are so many toxins and pollutants bombarding us these days. I do know that we are not only made of what our parents ate, drank, thought, etc. but also what our ancestors from several generations did too...

I think a holistic, organic, low chemical, emotionally balanced life style supports health the best.
Kathy