According to a recent study, an amino acid deficiency may be to blame for a rare form of hereditary autism. As stated in the Nature magazine article, genome sequencing in six children with Middle Eastern backgrounds uncovered “mutations in a gene that stops several essential amino acids being depleted” (Callaway). These mutations inactivate the enzyme BCKD-kinase. As we discussed in class, an enzyme increases the rate of a chemical reaction. However, why the lack of this enzyme would cause autism is still unknown.
Joseph Gleeson, a child neurologist who headed the study, suggests that low levels of branched amino acids to the brain, high levels of larger amino acids , or both might be behind autism symptoms.
Mice who also lacked BCKD-kinase exhibited tremors and epileptic seizures common to autism. However, when given dietary supplements of the branched amino acids, the chemical imbalance was treated and their symptoms disappeared.
Supplements given to the autistic children normalized their blood levels of amino acids. The patients’ conditions did not worsen, however, there was no real evidence that symptoms were reduced. Consequently, Gleeson hopes to conduct a clinical trial testing the effectiveness of dietary supplements in mitigating symptoms of autism and further identify children with the gene mutations for BCKD-kinase.
Matthew Anderson states that Gleeson’s study will “encourage other researchers to explore metabolic pathways as causes of autism.”
The amino acid deficiency may only compose a small percentage of all autism cases, but this is still a large step. The results of further study may present us with the “first treatable form of autism” (Gleeson).