Batten’s Disease is a rare inherited disorder affecting the nerve cells in the brain, eyes and other parts of the body, causing a progressive loss of vision and physical and mental skills.
What is the cause?
Batten’s disease is caused by an abnormal build-up of substances in the nerve cells throughout the brain and body which prevents them working properly. These substances are normally broken-down and removed from the body by an enzyme but, in Batten’s disease, the gene responsible for this process ( CLN3, on chromosome 16) is faulty. As the brain is the control centre of the whole body, blockages in the messages to other parts of the body will prevent those parts working efficiently, even though the parts themselves seem quite healthy.
How is it diagnosed?
The diagnosis is now usually made by examining a piece of skin, under a microscope, or by gene tests on blood.
Does it have any alternative name?
At the beginning of the 20th century Dr Frederick Batten described a group of disorders which now bear his name. Over time it was discovered that there were several types of the disease with similar, but distinct, features and ages of presentation; the different types are classified according to the age of presentation; Juvenile Batten’s is sometimes called Juvenile Neuronal Ceroid Lipofuscinosis ( JNCL) or Spielmeyer-Vogt-Sjogren Disease.
Is it inherited?
Batten’s disease is an autosomal recessive disorder; this means that both parents are carriers of the disease. Human beings have about 30-40,000 different genes, each of which has a function in making an individual person. The genes are arranged in pairs
(1 of the pair from each parent) on 23 chromosomes. Inevitably, some of these genes are faulty; a normal gene can overcome a faulty one, but if both genes in the pair are faulty, the genetic instructions cannot work. Most people carry different faulty genes but in Batten’s ( and other recessive conditions) parents, though healthy themselves, carry the same faulty genes, and risk passing them on to their children.
Each pregnancy carries a 25% chance of the child being affected
a 75% chance of the child NOT being affected.
Is prenatal testing available?
Due to recent advances in genetic studies, prenatal testing for Juvenile Batten’s Disease is now possible.
How common is it?
It is estimated that the incidence in the UK is approximately 1:150,000
How does the disease progress?
The child usually starts to show some signs of clumsiness, difficulty with school-work and deteriorating vision between the ages of 5-9 years; within a few years vision is completely lost and, for some time, this may be the only obvious problem. Over time, however, understanding and concentration become increasingly difficult and the child may also become unsteady and somewhat shaky. Epileptic seizures usually start around 10 years of age and, also at this age, behaviour can be erratic and challenging, presumably due both to the disease process, and frustration and confusion at what is happening. The course of the disease can vary quite considerably and the young person may seem quite stable for long periods but gradually, throughout the late teens, physical and mental skills are lost until he/she is unaware of his/her surroundings and needs total care. The condition is not a painful one and the young adult will, by now, be unaware of what is happening. Eventually the combination of the diseased brain and physical weakness becomes too great to sustain life and death usually occurs between the late teens and early thirties. Parents and carers will be aware of the young person’s increasing frailty, and death is usually relatively peaceful and expected when the time comes.
Is there any treatment?
Although there is no treatment yet available that can stop the disease, every effort is made to treat the symptoms; thus drugs can be given to help control seizures and other problems as they occur during the later stages of the disease, and feeding can be assisted along with other basic needs to keep the young person comfortable. When vision is lost, a specialist school with expertise in teaching visually impaired children, plus the understanding that learning will become increasingly difficult and that goals of schooling will be different, is necessary. The young person usually enjoys the independence, stimulation and routine that school can provide, either as a day or, maybe later, a residential pupil. Professional advice and/or medication may be necessary if the child’s behaviour becomes challenging.
Is any research being done?
Research is progressing rapidly with increasing understanding of the genes and how they work; treatment is obviously the goal but sadly, as yet, research has not yet led to an ability to stop the effects of the disease. Your neurologist and information available from the support group can keep you informed of research progress.
Is there a Support Group?
The Batten Disease Family Association can provide information, support and contact ( if wanted) with other families.