Genetic Subtypes of Mitochondrial Disease may be a factor in Hearing Loss

What is Mitochondrial Disease?

In plain English, it’s a genetic disease that causes your mitochondria to not efficiently turn sugar and oxygen into energy, and therefore the cells do not work as they were designed to. If you recall the famous liner – the mitochondria is the powerhouse of the cell – then it’s easier to understand that there is a problem with the powerhouse. Mitochondrial diseases can affect many parts of the body, including the brain, kidneys, muscles, heart, eyes, and especially the ears.

Researchers at the Children’s Hospital of Philadelphia (CHOP) and Lund University in Sweden have recently identified that hearing loss is one of the symptoms of Mitochondrial Disease. According to their published article in the journal of Molecular Genetics and Metabolism, they were able to determine some correspondences between the prevalence, severity, and timing of onset for hearing loss across different genetic subtypes of mitochondrial disease. By examining the records of 193 patients with primary mitochondrial disease who seeked medical attention at CHOP, they were able to determine roughly 27% of patients were diagnosed with sensorineural hearing loss. The ones most affected by hearing loss was the subgroup where mitochondrial DNA had pathogenic variants, which is located in the DNA of the mitochondria itself. They found that in most cases, DNA were missing segments, or nuclear DNA gene pathogenic variants. The genetic defects or mutations were found to impact mitochondrial function, causing inefficacy in transforming sugar and oxygen into energy.

So what’s the “too long, didn’t read” version? This study highlights that certain genetic variance are much more prone to developing sensorineural hearing loss, and can be as early as in one’s childhood. It doesn’t just affect children, either. Even if you don’t experience hearing loss in the early years of your life, it’s entirely possible for it to be a contributing factor that degrades your hearing ability faster than the average person would in the aging process. Because Sensorineural Hearing Loss, like all other forms of hearing loss, are permanent and irreversible, it’s highly advised for any persons who live with a known mitochondrial disease to regularly meet with their hearing specialist and family doctor to determine whether your hearing has taken a sudden turn for the worse. There may be no cure for mitochondrial diseases, but there are treatment options to lessen the effects and to prevent severe hearing loss. The best practice is to have an annual examination, just as you would with a generic body checkup.