A rare condition that's often inherited, Leigh's disease is typically detected soon after birth. Named after neuropsychiatrist Archibald Denis Leigh, the progressive disease affects the central nervous system. There's usually some type of triggering event, such as an infection, that initiates onset of the disease. There is no effective treatment for Leigh's disease, although success was seen with an experimental procedure performed on a mother at risk for having a child with the condition who subsequently gave birth to a healthy baby.
Leigh's disease is caused by genetic abnormalities. Scientists have identified at least 26 specific defects common in individuals who have the condition. Such defects are usually inherited, with the most common source being an autosomal recessive trait (genetic contributions from the father and mother). It can also be X-linked recessive, in which case the condition would only affect male babies. Defects within genes affect certain DNA sequences, usually in the mitochondrial respiratory system, due to the lack of an essential enzyme. Leigh's may also occur randomly with no clear cause or reason.
There's some discrepancy with how often Leigh's disease occurs, although it is rare when compared to other common birth defects such as Down syndrome and spina bifida. According to one estimate, Leigh's or a milder form of the condition with similar symptoms occurs with one of every 40,000 births. Researchers believe Leigh's may be under-diagnosed or sometimes misdiagnosed as another birth defect. According to the National Institutes of Health, the Mitochondrial DNA-associated form of the disease is even rarer, occurring in one out of every 140,000 births.
The only form of prevention for Leigh's disease is careful monitoring during pregnancy and testing to determine if any of the identified genetic defects are present. While there has been one documented case of successful intervention to prevent the disease from developing after birth, such procedures are still considered experimental. It's not yet understood why the genetic mutations that cause Leigh's disease occur. Genetic compatibility testing is another possible means of prevention in that genetic traits of both parents can be analyzed to identify possible defects associated with Leigh's disease.
If two carriers of the recessive trait for Leigh's have children, the risk of having a child with the condition increases to about 25 percent. Therefore, the only identified risk factors associated with Leigh's are having two parents who are contributing genetic traits linked to the disease or having a family history of the condition.
Leigh's disease sometimes develops a bit later in life or even during adult years. Unfortunately, prognosis for the condition isn't good. With severe forms of the genetic abnormality, death may occur within the first few years of life. Some patients have survived with the condition into their teen years, but this is a rare occurrence. Survival after diagnosis is usually longer if the condition develops in adolescent or adult years. There's promising research into the use of a chemical compound called chlorination acid and supplements that may help manage symptoms.