Niemann-Pick disease type C is a condition that makes it hard for the body to handle cholesterol and fats, causing an excess of these substances. This can lead to severe liver disease from too much cholesterol in the liver and problems in the brain from too much fat.
The first sign of this disease can show up at any age, from babies to adults, and it might include a swollen liver, a bigger spleen, or yellowing of the skin (jaundice). Sometimes, healthcare providers can find the disease in an unborn baby using ultrasound, but most of the time, it’s found in kids who go to school. Symptoms might include sudden muscle issues like seizures, being clumsy, shaking, trouble walking, sudden falls, slurred speech, and difficulty moving the eyes up and down. As the disease gets worse, these kids might have trouble learning, face mental health problems, or even experience memory loss, eventually losing the ability to talk. In the later stages, people with Niemann-Pick disease type C might lose the ability to move their face muscles or swallow, needing a tube for feeding through the stomach. For those diagnosed during childhood, the disease is often fatal in the late teens or twenties because of pneumonia. People diagnosed in adulthood generally survive for 10 to 20 years after diagnosis. Right now, there’s no cure for Niemann-Pick disease type C, so treatment focuses on managing symptoms.
Niemann-Pick disease type C is caused by pathogenic (disease-causing) variants in one of two genes, NPC1 and NPC2 gene and exhibits autosomal recessive inheritance. This means that both parents must be carriers to have a 25% chance to have a child with the condition. The risk of being a carrier is based on a person’s ancestry or ethnic background. For example, individuals of Ashkenazi Jewish descent have a 1 in 262 chance to be a carrier in the NPC1 gene. Most cases (95%) are type C1, while a smaller number (5%) are C2.
Other names for this condition are lipid histiocytosis, neuronal cholesterol lipidosis, sphingomyelin lipidosis, and sphingomyelinase deficiency.