Self-Cannibalization: Understanding Lesch-Nyhan Disease

While Lesch-Nyhan has a wide variety of symptoms, the most disturbing characteristic of this disease is for patients to resort to self-mutilating activities such as chewing on their own lips and fingers and, in extreme cases, biting off their own tongues and other body parts. The tendancy towards self-cannibalization is so intense in some that many of the patients have to have their teeth removed to prevent injuring themselves further.

What is Lesch-Nyhan Disease?

Lesch-Nyhan Disease, also known as self-cannibalization, is an inherited condition resulting from the lack of a certain enzyme in the body. This causes a buildup of uric acid which leads to conditions like kidney stones, problems with muscle control and learning disabilities. Only boys get Lesch-Nyhan disease, as it is caused by a mutation of the gene hprt on the X-chromosome - because girls have 2 X-chromosomes, the normal X-chromosome protects them from developing the condition. They may, however, be silent carriers that could potentially pass it on to any offspring they might have.

It's important to note that, just because a woman is a silent carrier doesn't mean that she will pass the mutated gene on to her children. She can also pass the healthy X-chromosome to her child. If she passes on the X-chromosome with the mutated gene, whether or not the child is affected is dependant upon gender; girls will become silent carriers, like their mothers, while boys can develop Lesch-Nyhan Disease.

Symptoms of Lesch-Nyhan Disease

There are a wide variety of symptoms that can affect boys with Lesch-Nyhan Disease. These include, but are not limited to the production of crystals in the joints (gout), kidney stones, excessive vomiting, stiffness in the joints (dystonia) or spasticity of the limbs. Some patients may suffer from various motor disorders that can cause excessive wiggling or jerking and flinging movements in addition to the more common stiffness.

While it was originally believed that children who suffered from Lesch-Nyhan Disease suffered severe mental retardation, studies have since proven that many children with this condition have a normal I.Q. and simply suffer from various learning disabilities. In many cases, these children have good memories and possess a good understanding of language skills, but have problems focusing, due to a very short attention span. In cases where educational programs are tailored to their individual needs, children who suffer from Lesch-Nyhan Disease actually do well in their lessons.

Lesch-Nyhan and Self-Cannibalizing

The most disturbing aspect of Lesch-Nyhan disease is the tendency for patients to inflict self-harm upon themselves. This can start as chewing on the insides of the cheeks, biting the lips and striking themselves in the head. In more extreme cases, some will literally chew off their own lips, tongue or fingers. Some children also attempt to injure their own eyes - gouging, clawing or poking at them.

Due to the tendency for Lesch-Nyhan boys to gnaw on their own lips and fingers, the disease is often referred to as the self-cannibalizing disease. In extreme cases, children are restrained or can even have their teeth removed in an effort to stop them from causing more serious harm to themselves.

Diagnosing Lesch-Nyhan Disease

Because of its rarity, it's often difficult to get an accurate diagnosis of Lesch-Nyhan Disease at an early age. If a doctor suspects the condition, however, diagnosis usually involves three main steps:

- Clinical Assessment: Having a medical professional evaluate the child is the first step in accurately diagnosis Lesch-Nyhan disease. During a medical assessment, a pediatrician will check the child for any evidence of developmental delay, any signs of self-biting or other self-injurious behaviors, and they will look for any signs that the body is producing too much uric acid. In some cases, the doctor may refer the family to a pediatric neurologist to determine the quality of neurological function in the child.

- Testing to Rule Out Other Diseases: The next step in diagnosing Lesch-Nyhan disease is to draw blood and urine samples to check for high levels of uric acid. This is still no guarentee that a child does or doesn't have Lesch-Nyhan's Disease, however. Further testing will be needed in order to measure the hprt gene and protein activity, which requires that more blood be drawn. In some cases, the doctor may call for a small skin sample as well, so that they are able to examine the living cells and how they are responding.

- Checking the Family: The final step in determining Lesch-Nyhan Disease is doing a genetic study of the mother and, if she is shown to carry the mutation, checking the other females in the family to see if they are also silent carriers. Because the X-chromosome is passed by the mother, there is no need to check the father.

Treating Lesch-Nyhan Disease

While there is no cure for Lesch-Nyhan Disease at this time, there are several things that can be done to help ease some of the symptoms of this condition. Since it's very important for Lesch-Nyhan patients to control the production of uric acid in their system, it's essential that anyone suffering from this condition drink lots of fluids in order to keep themselves well-hydrated. This will help to eliminate excess uric acid through the urine. Additionally, the medication Allopurinol can help by slowing down the production of uric acid.

While dealing with the neurological disabilities that are often present can be very troublesome, a comfortable wheelchair is essential and there are several medications that can help with the stiffness and twisting of the muscles. Behavior therapy may help with some of the self-injurious behaviors, or parents may have to resort to splints and loose restraints to help control children and keep them from self harm. In some instances, the teeth are removed and studies continue to try and find medications that will help to control this behavior without further aggravating existing conditions.

Sources:

Lesch-Nyhan.org - http://www.lesch-nyhan.org/en/ Information on the disease and various studies and treatments