Causes and risk factors
Niemann-Pick disease is an inherited disease. The disease is divided into 5 types: A, B, C, D, and E of which type A and B comprise type 1; and types C and D comprise type 2. Types A and B occur when the body cells do not properly produce a specific enzyme called acid sphingomyelinase [ASM]. This in turn causes an abnormal build up of sphingomyelin in the body cells, which eventually kills them. Type C: The body is unable to remove cholesterol and other excess body fats. This causes build-up of cholesterol in the spleen and liver and accumulation of excessive amount of other fats in the brain. Type D occurs when the body is unable to move cholesterol between brain cells.
Clinical presentation
Type A – Symptoms are apparent within the first few months of an infant’s life – they include feeding difficulties, impaired motor skills, tendency to catch frequent respiratory infections, abdominal swelling [due to hepatomegaly and splenomegaly], poor muscle tone, enlarged lymph nodes. Type B – Symptoms develop during late childhood or teenage years such as tendency to catch frequent respiratory infections, abdominal swelling [due to hepatomegaly and splenomegaly], impaired coordination, signs of delayed growth, mental retardation, and other psychiatric disorders. Types C and D – Symptoms can arise at any point in a person’s life – jaundice at birth, learning difficulties, movement of limbs is difficult and clumsy, speech and eye movements become difficult, hepatomegaly and splenomegaly, loss of vision or hearing, tremors, seizures, dementia, and other symptoms of brain damage.
Investigations
Medical history by the patient and clinical examination by the doctor helps in diagnosis.
Levels of ASM are measured in blood or bone marrow to diagnose type A and B of this condition. Skin biopsy is performed to diagnose type C and D.
Treatment
No treatment is available for type A. Bone marrow transplant and enzyme replacement therapy can be done for type B.
Complications
Complications such as rupture of the spleen and liver failure occurs.
When to Contact a Doctor
One must consult a doctor if the person shows symptoms like frequent respiratory infections, poor muscle tone, learning difficulties, etc.
Systems involved
Digestive system, CNS
Organs involved
GIT, brain, liver, spleen, bone marrow
