Late infantile variant usually manifests between 2 and 4 years of age with seizures and deterioration of vision. The maximum age before death for late infantile variant is 10–12 years. Juvenile NCL (JNCL, Batten disease, or Spielmeyer-Vogt), with a prevalence of one in 100,000, usually arises between 4 and 10 years of age; the first symptoms include considerable vision loss due to retinal dystrophy, with seizures, psychological degeneration, and eventual death in the mid- to late 20s or 30s ensuing. Adult variant NCL (ANCL or Kufs disease) is less understood and generally manifests milder symptoms; however, while symptoms typically appear around 30 years of age, death usually occurs 10 years later.All the mutations that have been associated with this disease have been linked to genes involved with the neural synapses metabolism – most commonly with the reuse of vesicle proteins. Genetics
Childhood NCLs are generally autosomal recessive disorders; that is, they occur only when a child inherits two copies of the defective gene, one from each parent. When both parents carry one defective gene, each of their children faces a one in four chance of developing NCL. At the same time, each child also faces a one in two chance of inheriting just one copy of the defective gene. Individuals who have only one defective gene are known as carriers, meaning they do not develop the disease, but they can pass the gene on to their own children.
The following signs and symptoms  may appear:
　

Individuals are more prone to respiratory infections
Development of scoliosis
Seizures or difficulty with movement
Skin and joints may become loose
Facial features change progressively; this may include:thickening of the skin
features becoming more prominent
large head
broad lower jaw
short, broad nose
rounded cheeksProgression of developmental and mental disabilities, including:progressive loss of speech
decrease in mental functioning
before school age, concentration lowers
development continues, but becomes slower than usualAn intellectual peak occurs in the mid-teens and allows a plateau for the disease. Once an individual hits the age of 25-30 the decrease begins again, including:learned skills become lost which result in severe learning disabilities
motor skills deteriorate
individuals become less mobile and more dependent(Children are physically uncoordinated, but remain able to play sports and do everyday activities until they reach adulthood.) During the first year of life inguinal and umbilical hernias are common. Less severe symptoms include:enlargement of the spleen and liver
diarrheaPeople with aspartylglucosaminuria may have lower than average height, because they tend to go through puberty earlier. Epilepsy may develop in adulthood. Finnish studies have shown that life expectancy is shorter than average. Genetics
Aspartylglucosaminuria is an autosomal recessive genetic condition that is inherited from both parents. The AGU patient is born with two copies of the mutated AGA gene. One copy comes from the mother’s egg and the other copy comes from the father’s sperm. In order to develop aspartylglucosaminuria, the individual must inherit changes in both of his AGU genes (autonomic recessive inheritance).