Ceroid lipofuscinosis, neuronal, 1
What is infantile neuronal ceroid lipofuscinosis?
Infantile neuronal ceroid lipofuscinosis (CLN1) is an inherited disorder that causes many health problems with the brain and nervous system. This disorder is also called PPT1-related neuronal ceroid lipofuscinosis. It is part of a group of disorders called the neuronal ceroid lipofuscinoses (NCLs) or Batten disease. The neuronal ceroid lipofuscinoses typically cause problems with vision, movement, and thinking ability that gets worse over time. The different types of neuronal ceroid lipofuscinoses are distinguished based on their age of onset. Infantile neuronal ceroid lipofuscinoses (CLN1) has an onset around 6-24 months of age. Typical signs include decreased vision, seizures, and developmental delay.
It is a lysosomal storage disorder. The PPT1 gene gives the body instructions to make an enzyme called palmitoyl-protein thioesterase 1. When a gene change/mutation happen in both copies of the PPT1 gene, either no or very little enzyme is made and the individual has symptoms of infantile neuronal ceroid lipofuscinosis. This disease causes problems in the way cells get rid of waste, such as excess protein and fats. When the cells cannot dispose of these extra items, there is a buildup of waste material. This harms the cells and can cause the problems we see in CLN1, such as seizures and vision loss. Life expectancy is shortened but variable. Typically, children with CLN1 live to age 2-9.
CLN1 is an autosomal recessive disorder, caused by two mutations (changes), one on each copy of the gene PPT1. One copy is inherited from the mother, the other copy from the father. When there are two mutations, there are no functioning copies of the gene.