परिभाषा
Niemann-Pick disease refers to a group of inherited conditions that affect the body’s metabolism. In patients with this rare disorder, fatty material builds up in various vital organs, sometimes including the brain.
There are four main types of Niemann-Pick disease:
- Type A—causes fatty substances to collect in the liver and spleen. Patients have severe brain damage and usually die by age two or three.
- Type B—affects the liver and spleen. Organs enlarge during the pre-teen years. There is usually no brain damage. Patients usually suffer from breathing problems and die in teen years or early adulthood. The prognosis is better for type B than type A.
- Type C—produces extensive brain damage. The liver and spleen are moderately enlarged. Type C usually starts in childhood and leads to death in teen years or early adulthood.
- Type D—similar to type C, but occurs only in people related to a family that lived in Nova Scotia at the start of the 1700s. Type D is now recognized as a variation of type C.
का कारण बनता है
Niemann-Pick disease is inherited. It is an autosomal recessive trait, which means that both parents must carry the abnormal gene for their child to inherit the disease. The exact cause depends on the type of Niemann-Pick disease.
Types A and B
A fatty material called sphingomyelin builds up in the patient’s organs. This substance is normally present in the membrane of most cells. The enzyme acid sphingomyelinase normally breaks down this substance. However, people with type A or B either do not have enough of this enzyme or this enzyme does not work properly. Without the properly functioning enzyme, this fatty material builds up in the cells. The cells die and the organ does not work properly.
Types C and D
In these two types, nerve cells in the brain are unable to move cholesterol out. This allows cholesterol to build up, which keeps cells from functioning normally.
जोखिम कारक
जोखिम कारक वह है जो किसी बीमारी या स्थिति के होने की संभावना को बढ़ा देता है।
Risk factors for Niemann-Pick disease include:
- Family members with Niemann-Pick disease
- Ashkenazi Jewish heritage (types A and B)
- Nova Scotia, French-Canadian ancestry (type D)
- Spanish-American population of southern New Mexico and Colorado (type C)
- North African ancestry, Maghreb region including Tunisia, Morocco, and Algeria (type B)
लक्षण
Symptoms of Niemann-Pick disease may develop during infancy, childhood, or the teen years, depending on the type of the disease. Symptoms vary. Not all patients will develop every symptom. Symptoms usually worsen over time.
टाइप करो
Symptoms begin within the first few months of life. They may include:
- Yellow skin and eye coloration
- Enlarged belly (due to enlarged liver and spleen)
- बौद्धिक विकलांगता
- Loss of motor skills
- Difficulty swallowing and feeding
- Failure to thrive
- बरामदगी
- दृश्य समस्याएँ
- Spastic movements (later in disease)
- Rigid muscles (later in disease)
टाइप बी
Symptoms start during pre-teen years. They may include:
- Yellow skin and eye coloration
- Enlarged belly (due to enlarged liver and spleen)
- बढ़े हुए लिम्फ नोड्स
- Osteoporosis, or brittle bones
- साँस लेने में कठिनाई
- Frequent respiratory infections
Types C and D
Symptoms may start in infancy, childhood, or teen years. They may include:
- Yellow skin and eye coloration
- Unsteady gait
- Trouble walking
- निगलने में कठिनाई
- Unable to look up or down
- दृष्टि खोना
- बहरापन
- अस्पष्ट भाषण
- Enlarged spleen and liver
- Loss of motor skills
- निगलने में कठिनाई
- Learning problems
- Sudden loss of muscle tone
- झटके
- बरामदगी
- Psychosis or dementia
निदान
The doctor will ask about the child’s symptoms and medical history, and perform a physical exam.
परीक्षण में शामिल हो सकते हैं:
- For all types:
- Complete blood cell count (CBC), measurement of acid sphingomyelinase activity in white blood cells
- DNA testing—to look for a mutated gene associated with the disease
- For type C:
- Skin biopsy —removal of a skin sample to check how it transports and stores cholesterol
उपचार
No specific or effective treatment currently exists for Niemann-Pick disease. Patients with type B may be given oxygen to help with lung problems. Research is focusing on the use of bone marrow transplantation, enzyme replacement therapy, and gene therapy.
रोकथाम
There are no specific guidelines for preventing Niemann-Pick disease. Prevention measures are currently available in the areas of genetic testing and prenatal diagnosis. If you have Niemann-Pick disease or a have a family history of the disorder, you can talk to a genetic counselor when deciding to have children.