Niemann-Pick disease | What you need to know

05.02.2025

Niemann-Pick disease is a genetic, autosomal recessive disease that disrupts the processes of breaking down and using cholesterol and other lipids in cells. Due to the accumulation of lipids, the cell loses its function and eventually dies. Niemann-Pick disease affects the brain, peripheral nerves, liver, spleen, bone marrow, and sometimes the lungs.

Table of Contents

The disease can begin at any age, but most often begins in childhood. Treatment is only symptomatic and is often fatal.

Symptoms

There are 3 main types of Niemann-Pick disease: A, B, and C.

Symptoms depend on the type and severity of the disease.

Motor muscle damage
muscle weakness
restriction of movement
Vision impairment and eye movement disorders
hearing loss
Sensitivity changes
sleep disturbance
Swallowing disorder
Slurred speech
Difficulty with memory and learning processes
Depression, paranoia, behavioral disorders
Enlargement of the liver and spleen
Recurrent infections (pneumonia)

In type A, symptoms begin in the first months of life, while in type B, symptoms begin later. In type C, symptoms begin mainly in adulthood.

reason

Niemann-Pick disease is caused by mutations in genes involved in lipid metabolism. The gene is inherited in an autosomal recessive pattern, meaning that a child must inherit the mutated gene from both parents for the disease to manifest clinically.

Risk factors

Risk factors for the disease do not depend on the type of disease. The frequency of the disease is almost the same in different populations. Niemann-Pick disease type A is more common in descendants of Ashkenazi Jews, type B is more common in North African populations, and type C is found with almost the same frequency in populations of different nations.

Types A and B

Types A and B of the disease are caused by SMPD1 Gene mutations that cause a deficiency or dysfunction of the enzyme sphingomyelinase. This enzyme helps cells break down and use sphingolipids (a specific type of lipid). The accumulation of sphingolipids damages the cell and leads to its death.

Type A is the most severe. Brain damage, liver enlargement, and nerve fiber death begin in the first months of life, and such children do not survive more than a few years.

Type B occurs in older children. Brain damage is rare in this form. Symptoms include neuralgic pain, difficulty walking, blurred vision, and enlarged liver and spleen.

Type C

Type C of the disease is caused by NPC1 და NPC2 Gene mutation, which leads to a deficiency of proteins involved in the transport and utilization of cholesterol and other lipids in the cell. Eventually, cholesterol and other lipids accumulate in the cells of the liver, spleen, and lungs. The brain and nerve fibers are also damaged. Symptoms include difficulty walking, swallowing, eye movement, hearing loss, and mental disorders. Symptoms can appear at any age. The condition worsens with age.