Study Shows Genetic Test can help in Autism Diagnosis

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A study has found that the recent technologies of genetic testing can help in identification of genetic mutations that are linked with Autism Spectrum Disorders (ASD). The study was posted in JAMA.

The tests are likely to detect mutations within a group of kids having particular physical anomalies. This would make clinical examination a key way to select the kids with ASD who can benefit the most from the genetic test.

“It is incontrovertible that precise diagnoses pave the way to better medical care, improved surveillance, better functional outcomes, and informed genetic counseling, often with the possibility of prenatal or preimplantation diagnosis,” states an editorial within the journal’s same issue.

The Study:

Stephen Scherer and his colleagues employed two new technologies – Whole-Exome Sequencing (WES) and Chromosomal Microarray Analysis (CMA), to identify percentage of children among 258 unrelated kids having ASD, who had genetic mutation, which may lead to the autistic features of those kids. Stephen Scherer, PhD, works at the “Hospital for Sick Children”, at Toronto in Canada.

From CMA, 24 of kids (9.3%) received a molecular diagnosis, and through WES, 8 out of 95 kids (8.4%) received a molecular diagnosis. Among kids for whom both the WES and CMA testing was done, 15.8% was the approximate proportion having a genetic cause.

For kids with more complex Autism Spectrum Disorders (ASD) on the basis of physical examination, the proportion having genetic mutation was much greater (37.5%).

Dr. Judith Miles at “University of Missouri Health Care”, Columbia, states that for Autism Spectrum Disorders and other types of behavioral disorders, the results of the study offer a clear guidance. He added – the data shows that the physicians taking care of kids with ASD, need to provide access to genetic evaluation through techniques, which are most likely to determine an etiological diagnosis.

Interest of parents in genetic test:

The study authors gave the conclusion that the study conducted by them demonstrates the genetic differences in relation to ASD children subgroups, on the basis of clinical evaluation.

It was noted by the authors that their data shows that ASD kids’ medical evaluation may be helpful in identifying people with more likelihood of getting a molecular diagnosis through genetic testing. They added that there is a likelihood that the genetic test of kids with ASD would increase continuously. In survey conducted on the interest of parents about genetic testing for ASD, 80% parents reported that they will prefer a sibling below 2 years of age to get tested for determining mutations linked to ASD risk, even in case the diagnosis cannot be confirmed or ruled out by the test.

If the results of the genetic test are positive for some kids, they can be offered treatment plans that target medical conditions associated with ASD. It was concluded by researchers that if the findings are replicated in more populations, they may inform proper selection of the molecular diagnostic test, for kids with ASD.

It was outlined by the editorial that karyotyping (chromosome profiling), is far lesser informative in comparison to new methods. But still, it’s recommended by the geneticists as test for ASD.

According to Dr. Miles, it’s likely that it wouldn’t be very long before evidence attained from the study would encourage a similar kind of recommendation for including whole-exome DNA sequencing in the form of an ASD test with high priority, especially for kids having physical dysmorphology.

Chloe Paltrow
Chloe Paltrow, a medical assistant. She has shared her knowledge in various websites and blogs like PsychCentral, Collective Evolution and Pick The Brain. Currently, she is studying how brain injury and brain disorders can be treated with hyperbaric chambers.