Batten Disease is named after the British paediatrician who first described the illness in 1903. The literature will sometimes refer to it as Spielmeyer-Vogt-Sjorgen-Batten Disease but that is obviously a mouthful to pronounce. Batten Disease was also seen as the juvenile form of Neuronal Ceroid Lipofuscinosis (or NCL) but has since become synonymous with NCLs in general.
Types of Batten Disease
There are four main types of NCL, all of which begin during childhood apart from one very rare form that first strikes in adulthood. Although the different forms have similar symptoms they seem to be due to different genetic defects.
Infantile NCL
Also known as Santavouri-Haltia disease, begins between about 6 months to 2 years of age and progresses rapidly, with children living only a few years. The affected children have abnormally small heads (microcephaly) and suffer from myoclonic jerks similar to epileptics. They also suffer delayed psychomotor development and a rapid deterioration in motor control.
Late Infantile NCL
Also known as Jansky-Bielschowsky disease, is very similar to the infantile NCL and begins between the ages of 2 and 4 years. Loss of muscle control (ataxia), seizures and mental deterioration eventually lead to death well before their teens.
Juvenile NCL
Batten Disease proper, begins between the ages of 5 and 8 years, with typical symptoms being vision loss, ataxia and seizures. The condition progresses less rapidly but few live beyond their early twenties.
Adult NCL
Also known as Kufs Disease or Parry's Disease, can develop at any time but normally before the age of 40. Symptoms are similar to the Juvenile NCL but rarely leads to blindness although it too will shorten the person's life expectancy.
How Many People Have Batten Disease?
Batten Disease is relatively rare, with an estimated 2 to 4 cases per 100,000 in the USA, but this incidence rises sharply within families that carry the defective gene. Indeed, if both parents are carriers then there is a 25% chance that a child will suffer from Batten Disease and a 50-50 chance that a child will become a carrier. The rarity but existence of the Adult NCL leads scientists to believe that the normally recessive disorder may become dominant in some carriers of just one defective gene.
What are the Causes of NCL?
The symptoms of Batten Disease are caused by a build-up of lipopigments in the cells of the brain, the eye, muscles and skin and cause the degeneration of neurons. Normally the body produces enzymes that clean up these lipopigments but researchers think that the defective genes limit the effectiveness of these enzymes. Lipopigments are also seen in senile degenerative disorders such as Parkinson's and Alzheimer's. In a sense, children with Batten's are going senile before they've even grown up.
How to Test for Batten Disease
As vision loss is one of the earliest signs of the onset of NCL, an eye specialist is often the first person to diagnose the illness. However, as other conditions can also lead to loss of cells within the retina one should then consult a neurologist. The quickest test is to take a skin or blood sample and look for the signs of lipopigments with an electron microscope. There are now diagnostic, carrier and prenatal testing for most forms of NCL as well as enzyme assays for Infantile NCL. Other tests, such as an electroencephalogram (EEG), a CT scan or an electro-retinagrams (ERG) can help gauge how advanced is the condition once confirmed.
Can Batten Disease be Cured?
As yet there is no known cure but over the last decade several genes have been found that correspond to the different NCL types. One specific gene located on chromosome 16 accounts for some 85% of all cases of Juvenile Batten Disease. The two Infantile forms of Batten Disease seem due to an enzyme being missing and this has led to gene replacement and stem cell transplantation therapies. Some positive results have been achieved in terms of halting the degenerative process although the condition has not yet been reversed. There is also a drug trial being conducted on Cystagon, but for the moment stem cell and gene therapies seems to offer the best hope.
Richard Mankiewicz - I write on a wide variety of topics from the broad perspective of the relationship between the arts and sciences. The aim is to break down ...
