Scientists found a new genetic disease in children
Researchers hope that identifying the rare disease will help understand more common brain disorders.Researchers from the National Human Genome Research Institute and the Undiagnosed Disease Program have discovered a unique neurological disorder. It causes speech and motor coordination problems and was found in three children.
Researchers believe the condition is caused by a genetic mutation that affects the ability of neurons in the brain to properly perform the cell recirculation function -- autophagy. In it, the cell's internal components are delivered inside its lysosomes or vacuoles, where they degrade. It is a natural process regulated by the cell's mechanism. It disassembles unnecessary or dysfunctional components.
Biologists hope that the discovery will help not only children but also other patients with impaired autophagy. It is seen in Alzheimer's disease.
The first subject in the study showed symptoms at age three. He had an abnormal gait, decreased coordination, and could not always maintain eye contact. As the boy grew older, he developed seizures, decreased reflexes, and partially unintelligible speech patterns. By the age of nine and a half, the child was diagnosed with ADHD, mild cognitive impairment and defiant oppositional disorder. With this condition, the patient has irritability and anger, and tends to argue with parents and other authority figures. It is worth noting that the boy has a sister who, despite early developmental problems, grew up without symptoms of the disorder.
The other two children diagnosed with the neurological disorder are sibling girls. One of them had abnormal hand movements, stumbled, and had an unusual, overly stare as a child. As she got older, the girl continued to have learning problems and difficulty speaking. The other sister also had motor control problems, which eventually resolved, although she also continued to have articulation problems.
After reviewing medical records, the researchers found the answer: all of the children had a mutation in the ATG4D gene. According to a 2015 study, it causes problems with motor control and eye movement in lagotto-romagnolo dogs. The authors of the new experiment found that the ATG4D mutation in the skin cells of the sick children did not interfere with autophagy. However, it did alter the cell recycling system in the brain.
After studying medical records, the researchers found the answer: all of the children had the ATG4D gene mutation. According to a 2015 study, it causes problems with motor control and eye movement, but only in lagotto-romagnolo dogs.
By experimenting with the cells in the lab, the scientists found - the ATG4D mutation in the skin cells of sick children did not interfere with autophagy. It causes cell recirculation disorders exclusively in the brain, without affecting the rest of the body organs.
Previous studies have shown that normal autophagy is associated with less arterial blockage and increased longevity. In addition, this process can be manipulated to reduce the number of amyloid plaques that cause Alzheimer's disease.