The number of rare diseases recorded throughout the history of medicine ranges from 5,000 to 7,000 different diseases or conditions, the vast majority of which have their origin in some kind of genetic alteration.
One of these rare diseases with a genetic burden is Batten disease . This is a medical condition that affects only children and its symptoms can lead to total dependence and sometimes death.
What is Batten’s disease?
Batten disease is a condition of genetic origin and potentially fatal course that affects the child’s nervous system. This disease begins to appear between the ages of 5 and 10 and its first symptoms are recognizable because the child begins to suffer from seizures and vision problems.
Other, much more subtle symptoms may appear initially , such as changes in the child’s personality and behaviour , difficulties and delays in learning, and clumsy movements and falls when walking.
This condition was first described in 1903 by pediatrician Frederik Batten, who gave it its current name. In addition it is also known as juvenile neuronal ceroid lipofuscinosis .
Main features of this disease
As mentioned above, Batten disease is a genetic condition that falls into the group of lysosomal storage disorders . It is very rare but has very disabling symptoms that may even lead to death.
Its genetic origin makes the cells of the human body unable to get rid of the substances and residues that circulate in it , causing an excessive agglomeration of proteins and lipids, that is to say, of fat-type extracts.
This storage of fatty substances ends up causing considerable damage to cellular structures and functions, which gradually leads to the distinctive gradual deterioration of this disease,
Likewise, the structure most damaged by Batten disease is the nervous system , being the brain the most damaged organ of the whole system.
As mentioned above, the current Batten disease mainly affects the nervous system, therefore all the symptoms pertaining to this disease will be related to the neurological area .
This symptomatology mainly affects three areas of great neurological weight: vision, cognition and motor skills, on which it exerts a progressive deterioration effect.
The following will describe the symptoms specific to each of the affected areas:
1. Progressive loss of sight
Progressive deterioration of vision is one of the first symptoms to appear in Batten disease. This symptom, which usually appears during the first years of life, evolves until the child becomes totally or partially blind when he or she is approximately 10 years old.
This category of symptoms includes some others, also related to vision, which appear throughout the development of the disease. These symptoms include:
- Retinitis Pigmentosa .
- Macular degeneration.
- Optical atrophy.
Other symptoms that appear during the early stages of the disease are repeated seizures. These seizure episodes are transitory incidents characterized by the presence of convulsions caused by abnormal or disproportionate neuronal activity .
Within these seizure episodes, two different classes can be distinguished:
These seizures are caused by abnormal functioning of a specific area of the brain. These seizures are characterized by a series of rapid movements. During the course of these crises the person may suffer loss of consciousness , and rhythmic and involuntary movements in any part of the body.
In this second type of seizure, abnormal neuronal activity affects practically all areas of the brain. Within this type of episodes are the absence seizures , or the tonic and atonic seizures among many others.
3. Cognition deficits
Both the agglomeration of lipid substances and the damage caused by the epileptic seizures, end up causing a serious neurological deterioration, which is manifested by a loss of the capacities that the child had already learned.
These cognitive deficits can affect any area of language, memory, thought or judgment . Likewise, this generation process tends to be accompanied by changes in the child’s behaviour, personality and state of mind, and may even present a psychotic episode.
4. Psychomotor problems
In Button’s disease , musculoskeletal and motor functions can also be affected , even hindering and conditioning the child’s mobility.
Within these psychomotor problems can occur:
- Involuntary contraction of the muscles .
- Burning sensation, numbness, itching and tingling in the upper and lower extremities.
- Hypotonia or hypertonia.
- Almost complete paralysis of the extremities .
5. Limitations and dependency
Finally, in the later stages of Batten disease children often have lost the ability to move and communicate , so they are in a situation of absolute dependence.
As mentioned above, Batten disease has a genetic origin. Specifically, its origin is located on chromosome 16 which has a series of mutations in the CLN3 gene . This gene is located in the nuclei of somatic cells.
Although the exact functions of this gene are not known, its mutation causes an abnormal and excessive accumulation of material and fatty substances in the tissues of the nervous system.
These lipopigments cause a series of important damages in the affected cellular areas , starting the distinctive progressive degradation of this condition.
In the event that family members are aware of a family history of Batten disease, it is necessary to perform a prenatal examination or assessment using amniocentesis testing or chorionic villus sampling.
However, if the assessment takes place after the child’s birth, a thorough evaluation will be necessary to ensure a correct diagnosis. Typical tests performed in this evaluation are
- Genetic studies.
- Nerve tissue biopsy .
- Physical examination.
- Neurological exploration.
- Evaluation of the visual capacity.
- Blood tests .
- Electroencephalography (EEG)
For the moment and due to the particularities of Batten disease, no protocol of action or treatment has yet been established that can stop the symptoms or make them remit.
However, the seizure symptomatology can be controlled by the administration of anticonvulsant medication . Also, thanks to the benefits of physical and occupational therapy, children affected by Batten disease can preserve the functioning of their body for as long as possible.
Stimulating patients and informing and supporting families through therapy groups can help or facilitate coping with this disease.