Working together, the group of 23 scientists from the US, Canada, and Israel are researching markers, both behavioral and biomedical, that indicate ASD. The earlier the markers are isolated, the earlier treatment for autism can begin. The researchers are not only working toward the goal of early identification, but also toward the development of treatments to prevent symptom development.

Because siblings of children with ASD are at a risk for ASD that is possibly as high as 10 times greater than that of the general population, studying siblings of autistic children presents a unique opportunity for researchers to identify autism very early in a child’s life. The research into the underlying mechanics of autism also affects clinical practices for children diagnosed with ASD.

Research is ongoing; new studies are planned to investigate environmental and genetic risk factors as related to autism, and a study of more than 1500 infant siblings of children with ASD is planned.

Results of this ongoing research will shed light on both risk factors connected to developing ASD as well as underlying causes of autism. While no one cause has been identified, the more research that is done, the closer we are to identifying causes and to developing new treatments that will ensure a positive outcome for children with ASD.

Read more about The High Risk Baby Siblings Research Consortium here.

Research led by Harvey J. Kliman, M.D., research scientist in the Department of Obstetrics, Gynecology & Reproductive Sciences at the Yale School of Medicine and reported in the June 26, 2006, online issue of “Biological Psychiatry” is shedding light on pathologic findings in the placentas of children with autism spectrum disorder (ASD).

The research group designed a study to determine if the presence of trophoblast inclusions in the placenta, a placental abnormality, is a marker for ASD. The researchers, using microscopic examinations of placental tissues, discovered that the placentas from ASD children were three times more likely to have these inclusions.

Kilman reports that “We knew that trophoblast inclusions were increased in cases of chromosome abnormalities and genetic diseases, but we had no idea whether they would be significantly increased in cases of ASD. These results are consistent with studies by others who have shown that ASD has a clear genetic basis.”

Trophoblast inclusions appear to be the result of abnormal cell growth in the placenta. Kliman offers the analogy of these inclusions as akin to a check-engine light on a car’s dashboard: “When the light goes on it simply means that something is not right. If the light is on and there is, for example, steam coming from under the hood, then it is likely that the radiator is leaking. However, if the check engine light is on and there is nothing obviously wrong, then the car should be carefully checked.”

Larger studies are in the works; the Yale team plans to examine the placentas in greater detail. They will examine the placentas of the children in the study in greater detail to gain insight into the biological basis of the inclusions in ASD.

Fred R. Volkmar of the Yale Child Study Center states that “If the work is confirmed by the next series of studies, then the finding of trophoblast inclusions at the time of birth in the absence of any obvious genetic abnormalities would be an indication to have a child examined by a specialist to determine the presence of ASD.”

While initial screening for ASD may be performed by a child’s pediatrician, additional screening and diagnoses are generally done by a specialist. The earlier a diagnosis is made, the earlier treatment and interventions can begin. The study of these placental abnormalities may lead to earlier diagnoses.

The findings of this study, conducted by researchers at the University of California, San Diego (UCSD) School of Medicine and Children’s Hospital and Health Center, is meaningful in terms of earlier diagnosis that can lead to earlier intervention and therefore to improved outcomes for children diagnosed with autism.

Autism is usually diagnosed by age 3; diagnosis is made base on observation of behavior, not a medical test. The earlier the diagnosis is made, the earlier treatment can begin. The early warning sign of increased brain growth occurs before behavioral symptoms of autism are noted.

Researchers in the UCSD study found that the rapid brain growth in children with autism means that “when the brain is experiencing the world and deciding how to construct itself, it’s growing too fast in the infant with autism,” according to the study’s senior author Eric Courchesne, Ph.D. In short, the brain cannot keep up with experiences and information and this makes “it very hard for autistic children to make sense of the world they live in,” says Courchesne.

The more excessive the brain growth, the more severe autism is, according to study results.

Researchers studied medical records of 48 children aged 2 to 5 who have an autism diagnosis; head circumferences were compared to the Centers for Disease Control and Prevention’s growth charts for normal development. The findings were that, on average, the head circumference of autistic children at birth was smaller than about 75 percent of other newborns. However, in the first year, these children had a rapid growth in brain size, reaching the 85th percentile (only 15 % of other newborns had a smaller head size) at around 1 year to 14 months old. Then, brain growth slowed.

Courchesne explains: “This burst of overgrowth takes place in a brief period of time, between about two months and six to 14 months of age. So, we know it cannot be caused by events that occur later, such as vaccinations for mumps, measles and rubella or exposure to toxins during childhood.”

This study, according to Courchesne, “provides, for the first time, a developmental process to target for animal model studies of the disorder. Animal models that accurately mimic these abnormal growth events will be necessary in order to discover causes and biological treatments for autism. Once we know what causes this specific growth defect, it may be possible to use biological treatments to successfully intervene before the overgrowth begins, thereby allowing the brain and behavior to develop down more normal paths.”

While certain other conditions such as hydrocephalus or certain metabolic disorders can cause a large head circumference, they are much less common than autism.

Research has found that experience-guided growth is beneficial to human brain development. Experiences that pass through certain pathways in the brain lead to higher order neurobehavioral functions and skills, such as motor skills, linguistic, emotional, and cognitive skills.

The findings of this study have positive implications for treatment. Courchesne states, “Using our findings as an early indicator of autism, intervention might begin two or three years earlier when the brain might be at a more malleable stage and so, might result in a better outcome for the child.”

While all it takes to measure head circumference and, consequently, brain size, is a tape measure, not all pediatricians include this in routine visits. The research team advocates routine head circumference measures in the first year of life.

In 2007, the results of the largest-ever genome scan were published. Performed by over 120 scientists working in more than 50 research institutions that comprise the Autism Genome Project, the research began in 2002 as a collaboration to identify genes that may cause autism.

Funded by Autism Speaks, the research team used looked for genetic similarities in the DNA from nearly 1,200 families. Findings of the study included the discovery that neurexin 1, part of a family of genes previously linked to autism, and a gene on chromosome 11 may be linked to autism.

In addition, researchers believe there may be as many as 30 genes involved in autism. In short, if a child has one or more of these indentified genes, then he or she has a higher risk of being born with autism.

Clearly, ongoing research is necessary in order for researchers to get closer to pinpointing a particular gene or genes that are implicated in autism. The next phase of the Autism Genome Project will continue to try to isolate genes that cause autism. The earlier autism is diagnosed, the earlier treatment and intervention can begin; early treatment is imperative in helping children with autism diagnoses to lead more fulfilling lives. Finding causes of autism is a positive step toward early diagnosis.

Resources & References

Read the National Institute of Mental Healh’s press release here.

Visit the Austism Genome Project’s website here.

While there are no known causes of autism, research into causation is ongoing. One such causal connection being explored is a genetic cause of autism.

A study at the David Geffen School of Medicine at UCLA has uncovered genetic connections between autism and speech delays. Funded by the National Institute of Mental Health, National Institute of Neurological Disease and Stroke, Cure Autism Now Foundation and UCLA Center for Autism Research and Treatment, the study was lead by Dr. Daniel Geschwind; the findings of the study were published in The American Journal of Human Genetics’ January 10, 2008, online edition.

This study follows an earlier one of DNA samples from families with an autistic child; that study revealed that autism was connected to a specific region of Chromosome 7 (called 7q35). In the next study, researchers studied genes from DNA samples from 172 families. The region’s implication in autism was confirmed by a subsequent study.

A key finding, according to Dr. Geschwind, is that the gene the research isolated, called contactin-associated protein-like 2 (CNTNAP2), “not only may predispose children to autism, [but . . .] also may influence the development of brain structures involved in language, providing a tangible link between genes, the brain and behavior.”

Postdoctoral fellow Brett Abrahams, who led part of the research, states that the research discovered that “CNTNAP2 concentrated in the brain’s structures that are involved in higher cognition gives us strong clues about how its disruption might adversely shape brain development, including speech and language”

Another finding was statistical evidence that the gene is strongest in families with autistic boys than in those with girls or with boys and girls.

Further effects of the study may be discoveries about whether CNTNAP2 has a role in language development in normally developing children.

While research into the causes of autism is ongoing and no one cause has been found, research such as this brings us closer to an understanding of this complex disorder.

Researchers are investigating the causes of autism and of this disparity between the sexes. Recent research published in Molecular Psychiatry and headed up by Dr. Stanley Nelson, professor of human genetics at the David Geffen School of Medicine at UCLA, focuses on the role that the gene CACNA1G plays in autism. Funding for the study was provided by the National Institute of Mental Health and Cure Autism Now, which has since merged with Autism Speaks.

Nelson explains the study’s findings: “We found that a common form of the gene occurs more frequently in the DNA of families that have two or more sons affected by autism, but no affected daughters. Our study may explain why boys are more susceptible to the disorder than girls.”

The research team studied the DNA of 1,046 members of families in which at least two sons were diagnosed by autism, looking for common gene variants: genes in which subtle changes have occurred.

“We wanted to identify what was happening in this region of Chromosome 17 that boosts autism risk,” said Nelson. “When the same genetic markers kept cropping up in a single region of the DNA, we knew we had uncovered a big clue.”

The gene CACNA1G, which helps move calcium between the cells, has a common variant that appears in the DNA of nearly 40 percent of the population.

“This alternate form of CACNA1G consistently increased the correlation to autism spectrum disorder, suggesting that inheriting the gene may heighten a child’s risk of developing autism,” observed Nelson. While the gene cannot be considered, on its own, a risk factor for autism, what is not known is the role the gene plays in a higher risk of autism.

Nelson concedes that “We need a larger sample size to identify all of the genes involved in autism and to solve the whole puzzle of this disease.”

In order to help solve the puzzle, the UCLA team will sequence the gene in people with the variant form to identify the exact change that increases autism risk.

While identifying autism on the genetic level carries with it its own set of moral and ethical conundrums, one thing is clear: early diagnosis and intervention can significantly help those with autism diagnoses. Increased research into risk factors for autism may help researchers to diagnose autism at an earlier age. Autism is usually diagnosed around age 3. Since early intervention and treatment are crucial in helping those affected lead normal lives, early identification is equally crucial.

The technology measures eye direction while 9 to 12 month old babies look at eyes, faces, and bouncing balls on a computer screen. This new technology allows researchers to “distinguish between a group of siblings with autism from a group with no autism — at nine months and 12 months,” says Rutherford, and the study can be completed in 10 minutes without being influenced by intuition or a clinician’s report.

Because the earlier one is diagnosed with autism, the better the prognosis, Rutherford states that, “There is an urgent need for a quick, reliable and objective screening tool to aid in diagnosing autism much earlier than is presently possible.” Current diagnostic tests are reliable at around age 2.

Early detection of autism can have a profound effect on the treatment and interventions autistic children receive, so this tool is an invaluable resource for early diagnosis.

Reference: Science Daily

While autism is usually diagnosed before age 3, treatment and interventions for autism do not have a definitive endpoint.  One cannot be “cured” of autism, but rather continually treated.  Because of the ongoing nature of the disorder and the difficulty in pinning down a date of onset, continual research into the causes of and treatments for autism is mandatory if we want to effectively assist those affected by autism.  Researchers are continually discovering more and more about the potential causes of autism, and this research helps to shape treatments and interventions for those affected by it.

Research into potential causes of autism have uncovered connections between low birth weight, delivery before 35 weeks, low Apgar scores (scores used to evaluate a baby’s health at 5 minutes after birth), and breech presentation at birth and an increased risk of autism.

Research into the genetic component of autism has uncovered gene development that is potentially responsible for the development of autism and a possible hereditary connection.

Further studies have linked a mother’s autoimmune system and incidents of maternal psychoses with an increased risk for autism as well as the connection between certain medical conditions and a susceptibility of autism.

Research has not developed a medical test that can rule out autism, but an increased awareness of the symptoms associated with autism has led to more effective diagnoses:  the more parents know about the behaviors associated with autism, the more likely they are to seek evaluation and treatment.

Research and correlated increased public and professional awareness of autism has increased the chances of getting a prompt diagnosis and subsequent treatment of those affected by autism. This increased awareness has led to developments in more effective methods of teaching those affected by autism and in assisting them with managing the disorder.

Although research has been conducted regarding a possible link between childhood vaccines, particularly those containing the preservative thimerosal, and an increased risk in autism, no scientific evidence exists that show a causal connection between the two.

Research has also helped to start an important discussion within the public and professional communities that can help to understand, support, and treat those affected by autism.

Clearly, ongoing research is essential in order to understand the complexities of this disorder.  With continual research into causation and treatment, earlier diagnoses and treatment will be possible.

References and Additional Resources:

Autism Society of America

Autism Speaks

Autism research abstracts