“New Study Links POLR3B Gene to Rare Brain Disorder”
A recent study has shed light on a specific genetic condition linked to the POLR3B gene, which plays a crucial role in the synthesis of small non-coding RNAs in our cells. Variants—or changes—in this gene have already been connected to a type of inherited disorder known as hypomyelinating leukodystrophy, which affects the brain’s white matter. More intriguingly, researchers discovered that some people with new (de novo) mutations in POLR3B also experience symptoms like ataxia (balance issues), spasticity (muscle stiffness), and peripheral neuropathy (nerve damage). In fact, three of these individuals had seizures, prompting this study to focus on defining the type of epilepsy linked to these POLR3B variants.
In their investigation, the researchers utilized online tools to find 13 patients who had these new POLR3B variants. They gathered detailed information about the patients, including their genetic make-up and symptoms. The findings were quite significant: all patients had unique mutations, and most of these mutations were deemed pathogenic, meaning they likely contribute to disease. The patients experienced various types of seizures, such as generalized myoclonic seizures and tonic-clonic seizures, typically between six months and four years of age. Notably, seven of the patients had a specific kind of epilepsy characterized by myoclonic-atonic seizures, and many faced challenges in controlling their seizures with treatment.
Unfortunately, the study revealed that seizures were generally resistant to treatment, with only three patients managing to become seizure-free. It was also observed that developmental delays were common among these patients, often showing signs before the onset of seizures. Some cases even reported stagnation or regression in development following the start of seizures. However, the researchers did find that certain treatments, like sodium valproate and the ketogenic diet, had varying degrees of effectiveness for managing the seizures.
Beyond epilepsy, the researchers also noted other associated features in these patients, such as ataxia, microcephaly (smaller than average head size), and spasticity. The findings highlight POLR3B as a new genetic condition linked to developmental and epileptic encephalopathies, with a particular emphasis on myoclonic-atonic seizures as the most common seizure type. This research not only enhances our understanding of the genetic underpinnings of these conditions but also emphasizes the complex interplay between genetics and neurological health.