Gaucher's disease
Gaucher's disease is named after the French doctor Philippe Gaucher who first described it in 1882. Gaucher's is a genetic disease in which a fatty substance accumulates in cells and certain organs of the body. Gaucher's is a hereditary deficiency of the enzyme ‘glucocerebrosidase' which acts on a fatty substance ‘glucocerebroside', which accumulates particularly in the white cells. Glucocerebroside collects in the spleen, liver, kidneys, lungs, brain and in bone marrow.
Symptoms of Gaucher's disease
Neurological complications
Enlarged spleen and liver
Skeletal disorders
Lymph nodes swelling and joints
Distended abdomen
Brownish tint in skin
Anemia
Low blood platelets
Yellow fatty deposits on the white of the eye
Painful bone lesions
Persons with gaucher's disease are more susceptible to infections.
Gaucher's disease types
Type 1 – This is the most common form of the disease which causes enlargement of liver and spleen, causes pain and breaks bones, and also causes lung and kidney problems. However, this does not involve the brain. Type 1 Gaucher's can occur at any age.
Type 2 – This can cause severe damage of the brain and it appears mostly among infants. Children affected with Gaucher's die by age 2.
Type 3 – Liver and spleen enlargement occur in this type and there are some signs of brain involvement though it is gradual.
Although Gaucher's disease has no cure, there are treatment options for types 1 and 3. Enzyme replacement therapy is usually very effective in these types. However, treatment options for type 2 are very minimal.
Causes of Gaucher's disease
As described, Gaucher's disease is a rare and inherited disorder and build up of the enzyme glucocerebroside prevents the other organs in the body to function properly. The carrier rate among Ashkenazi Jews is almost 8.9% while the incidence at birth is 1 in 450. All the three forms of Gaucher's disease are caused by glucocerebrosidase activity deficiency. This is due to mutations in GBA, a structural gene that encodes the enzyme.
Diagnosis of Gaucher's disease
Normally the couples are tested for the Gaucher's disease. Blood samples are diagnosed and the level of enzyme responsible for Gaucher is measured. Gaucher gene can be analyzed at the molecular level. Affected individuals have two Gaucher genes and low enzyme levels when the other is a non carrier. Enzyme testing as a means of carrier identifications for Gaucher's disease is about 90% accurate. As such there could be an overlap in the range of enzyme activity values between non-carriers of the disease and the carriers. Hence, use of direct molecular DNA testing is more reliable and almost 98% accurate.
During pregnancy, all types Gaucher's disease can be detected through procedures called amniocentesis. Prenatal diagnosis is available for those who are at risk for having a child with Gaucher's.
Treatment
Spleen removal and bone marrow transplants were adopted previously but with substantial risks. Enzyme replacement therapy has been made available recently to combat the underlying problems in Gaucher's disease. Although originally the enzyme has been placentally derived, since 1994 Cerezyme, a recombination of form of acid beta glucosidose, which is FDA approved has been used for the treatment of symptomatic Gaucher's disease. Here regular intravenous infusion of enzyme which has been biochemically modified is done so as to target the Gaucher cell. However, enzyme therapy is complicated as the minimal effective dosage and optimal frequency of administration has not been established. Therefore, it calls for a very careful and coordinated management by physicians with special expertise in Gaucher's disease.
Abdominal MRI
Abdominal MRI is used to detect any abdominal growths. It is a non-invasive procedure that uses powerful magnets and radio waves to produce pictures of the inside of the abdomen. Abdominal MRI can distinguish tumors and other lesions from normal tissues. It also provides information to determine the size, extent and spread of abdominal tumors. For patients who cannot receive iodinated contrast dye and in whom angiography has to be avoided, abdominal MRI is used. Abdominal MRI reveals several of disorders that includes renal vein thrombosis, renal arterial obstruction, kidney enlargement, inflammation of the kidney, acute tubular necrosis, tissue damage in kidneys, pancreatic cancer, adrenal masses, mass of the gall bladder, obstruction in liver, enlarged spleen, distended gall bladder or bile duct, abscess, hemangiomas and other abnormal abdominal conditions.
Ultrasound
Ultrasonography is a medical imaging technique that is also called ultrasound scanning or sonography. High frequency sound waves and their echoes and used in this technique for obtaining images from inside the human body. The echoes of sound waves reflected from the human body are recorded and displayed as a real-time visual image. This technique is similar to the echolocation used by bats, whales and dolphins. The sonar used by submarines also operates the same technique. Ultrasound is useful method to examine many of the body's internal organs like heart, liver, gallbladder, spleen, pancreas, kidneys and bladder.
Movement of the internal tissues and organs are captured in ultrasound. Ultrasonography enables the physicians to diagnose a variety of disease conditions and also assess the damage caused to the systems.
The ultrasound machine transmits high frequency sound pulses into the human body by using probes. These sound waves that travel into the body hit a boundary between the tissues inside the body and reflect the sound waves to the probe. Some waves travel even further and they reach another boundary and then get reflected back. The waves that are reflected are picked up by the probe and relayed back into the ultrasound machine.
The ultrasound machine in turn calculates the distance from the probe to the tissue or organ by using the speed of sound tissue and the time of each echo's return. The machine displays these distances and intensities of the echoes on the screen. Through the echoes that are produced the sonologist can identify how far away an object is, how large it is, its shape and consistency (fluid, solid or mixed). Two dimensional images are formed and reflected on the screen. Different types of ultrasound are used for different disease conditions. Ultrasound is used in a variety of clinical settings including obstetrics and gynecology, cardiology and cancer detection.
The abdominal ultrasound, pelvic ultrasound and transvaginal ultrasound are commonly used.
Bibliography / Reference
|
