Niemann-Pick Disease Type C
Description
Niemann-Pick disease type C (NPC) is a rare, inherited disorder that affects the brain, liver, spleen, and other organs. It‘s caused by a buildup of cholesterol and other lipids in cells, particularly in the brain. This buildup disrupts normal cell function, leading to a variety of symptoms, primarily neurological.
Genes Involved
NPC is caused by mutations in either the NPC1 or NPC2 gene. These genes provide instructions for making proteins that are involved in the transport of cholesterol and other lipids within cells. Mutations in these genes disrupt this process, causing the buildup of lipids.
Recognizing the Signs and Symptoms
Symptoms of NPC typically begin in childhood, although they can appear later in life. They can include:
- Neurological: Delayed development, difficulty walking, loss of coordination, seizures, involuntary movements, slurred speech, and dementia.
- Liver and spleen: Enlarged liver and spleen, leading to abdominal swelling.
- Eye problems: Eye movements may be affected, and the eyes may appear to have a cherry-red spot.
- Other: Difficulty swallowing, breathing problems, and feeding difficulties.
Symptoms can vary widely in severity and age of onset, making diagnosis challenging.
Causes
NPC is inherited in an autosomal recessive pattern. This means that both parents must carry a copy of the mutated gene for their child to have the disease. If both parents are carriers, each of their children has a 25% chance of inheriting the disease.
Inheritance/recurrence risk
The chance of having another child with NPC depends on the parents‘ genetic status. If both parents are carriers, each pregnancy has a 25% chance of having a child with NPC, a 50% chance of having a carrier child, and a 25% chance of having a child without the gene mutation.
Genetic counseling and testing can help families understand their risk of having a child with NPC.
