Neuronal Ceroid Lipofuscinoses (or NCLs)
Batten Disease is a fatal, inherited disorder of the nervous system that begins in childhood. It is named after the British pediatrician who first described it in1903. Also known as Spielmeyer-Vogt-Sjogren-Batten Disease, it is the most common form of a group of disorders called neuronal ceroid lipofuscinoses (or NCLs).
Although Batten Disease is usually regarded as the juvenile form of NCL, it has now become the term to describe all forms of NCL. The basic cause, progression, and the outcome are the same. The forms of NCL are classified by age of onset, and eight different genes [CLN1 – CLN8] have been identified as causing the disorder.
The first sign of the disease is often loss of vision, and may first be suspected during an eye examination. Other early signs are subtle, but may include personality and behaviour changes, slow learning, clumsiness or stumbling. Over time, affected children suffer mental impairment, worsening seizures, and progressive loss of sight and motor skills. Eventually, children with Juvenile Batten Disease become blind, bedridden, and unable to communicate. Juvenile Batten Disease is always fatal by the late teens or twenties.
There are four main types of NCL/Batten Disease, including two forms that begin earlier in childhood and a very rare form that strikes adults. The symptoms are similar but they become apparent at different ages and progress at different rates.
Infantile NCL (Santavuori-Haltia disease): begins between about 6 months and 2 years of age and progresses rapidly. Affected children fail to thrive and have abnormally small heads (microcephaly). Also typical are short, sharp muscle contractions called myoclonic jerks. Initial signs of this disorder include delayed psychomotor development with progressive deterioration, other motor disorders, or seizures. The infantile form has the most rapid progression and children live into their mid childhood years.
Late Infantile NCL (Jansky-Bielschowsky disease) begins between ages 2 and 4. The typical early signs are loss of muscle coordination (ataxia) and seizures along with progressive mental deterioration. This form progresses rapidly and ends in death between ages 8 and 12.
Juvenile NCL (Batten Disease) begins between the ages of 5 and 8. The typical early signs are progressive vision loss, seizures, ataxia or clumsiness. This form progresses less rapidly and ends in death in the late teens or early 20s, although some may live into their 30s.
Adult NCL (Kufs Disease or Parry's Disease) generally begins before the age of 40, causes milder symptoms that progress slowly, and does not cause blindness. Although age of death is variable among affected individuals, this form does shorten life expectancy.
A related disorder, Northern Epilepsy [(NE) or Progressive Epilepsy with Mental Retardation (PEMR)], so far identified only in patients of Finnish origin, generally begins between 5 and 10 years of age, and is characterised by tonic-clonic or complex partial seizures, and mental and motor deterioration. Although the frequency of seizures declines after puberty, cognitive function continues to decline. Some affected individuals have lived past the age of 60.
Batten Disease and other forms of NCL are relatively rare, occurring in an estimated 2 to 4 of every 100,000 births in the United States. These disorders appear to be more common in Finland, Sweden, other parts of northern Europe, and Newfoundland, Canada, although the disease has been identified worldwide. Although NCLs are classified as rare diseases, they often strike more than one person in families that carry the defective genes.
In those families where the disease-causing mutation has been identified, prenatal and carrier testing is available for family members willing to be tested, and genetic counselling can assist them to make informed decisions according to their personal circumstances.
Siblings of an affected individual have a 25 % chance of also being affected, a 50% chance of being unaffected but being a carrier of the defective genes, and a 25% chance of being both unaffected and a non-carrier. Unaffected siblings of parents with an affected child also have a 50% chance of being carriers.
In families known to be carriers of the defective genes, prenatal testing can be performed at either 10-12 weeks [by chorionic villus sampling], or 16-18 weeks [amniocentesis] to discover if the foetus is affected.
As yet, no specific treatment is known that can halt or reverse the symptoms of Batten Disease or other NCLs. However, seizures can sometimes be reduced or controlled with anticonvulsant drugs, and other medical problems can be treated appropriately as they arise. At the same time, physical and occupational therapy may help patients retain function as long as possible.
Some reports have described a slowing of the disease in children with Batten Disease who were treated with vitamins C and E and with diets low in vitamin A. However, these treatments did not prevent the fatal outcome of the disease.
Affected children suffer increasing mental impairment, worsening seizures, and progressive loss of sight and motor skills. Eventually, children with Batten disease become blind, bedridden and demented. Batten disease is often fatal by the late teens or twenties.
Further Information and Support:
Reviewed by Professor Kathryn North, Head, Neurogenetics Research Unit, Children’s Hospital, Westmead.