Biology 202
2003 First Web Paper
On Serendip

Ethnicity can provide individuals with wonderful traditions and celebrations of one's heritage. However, for some Ashkenazi Jews, ethnicity brings them much more than they bargained for: a rare condition causing a wide array of liver, lung, spleen, bone and bone problems. Ethnicity brings them Type I Gaucher Disease. Type II and Type III are the two other forms of this rare genetic condition, and can occur at equal frequencies in all ethnic groups. Gaucher disease was first described in 1882 by Doctor Philippe Charles Ernest Gaucher from France (2) . Type I , the most frequently seen form of the disease, can affect people of multiple ethnic backgrounds. However, its prevalence is greatest by far in the Ashkenazi Jewish population, making it the most common genetic disease within this ethnic group.

While the Type I Gaucher Disease is non-neuronopathic (not affecting the nervous system) the second two types are neuronopathic. Yet even though the three types of Gaucher produce different symptoms, all three types result from the same cause: a lack of glucocerebrosidase enzyme. The glucocerebrosidase enzyme functions to break down the compound glucocerebroside, a fatty compound which usually is stored in all cells of the body in very small amounts. In Gaucher patients, an excess of glucocerebroside builds up in the body, and is stored abnormally in lysosome, or storage cells (3) . Typically, macrophages are able to aid in the degradation process of glucocerebroside. However, due to the lack of glucocerebrosidase in Gaucher patients, glucocerebroside stays in the lysosome, preventing macrophages from acting upon them. Macrophages which are enlarged and contain an abnormal buildup of glucocerebroside are known as Gaucher cells. (1) . In affected patients, Gaucher cells can be found in bone marrow, liver and spleen cells. (2) .

Each of the three types of Gaucher Disease affect many systems of the body. Type I of the disease, which is the most mild form and is most frequently seen, is the only form of Gaucher which does not affect the nervous system. Typically, the average age of onset for Type I Gaucher is 21 years (6) . Approximately 1 in 10 Ashkenazi Jews is heterozygous for type I. Although the condition is non-neuronopathic, patients can exhibit a wide array of symptoms ranging from increased spleen and liver volume, lung compression, a variety of bone problems including lesions, bone tissue death and pain, and anemia and easy bruising. Individuals with Type I Gaucher Disease typically have a life span of 6 to 80 years (5) . Within families, the severity of Type I of the condition varies immensely, thereby making it impossible to determine which family members will suffer from the most severe symptoms. Gaucher Disease is different from most other autosomal recessive conditions in that one of the nonfunctional glucocerebrosidase genes (which are characteristic of Gaucher Disease) is passed o1n to each of the patient's offspring, causing them all to be carriers. Among Ashkenazi Jews, it has been presumed that around 1 in 450 Ashkenazi Jews has two mutated copies of the glucocerebrosidase gene (4) .

While Type I Gaucher is by far the most common form of the disease, Type II is excessively rare; among newborns, less than 1 in 100,000 have Type II Gaucher. Its onset occurs in infancy, and unlike Type I, Type II Gaucher is highly neuronopathic, and causes drastic neurological problems, usually at age one. Type II typically leads to death by the age of two due to the degree of severity of its effects on the nervous system (3) . In addition to the severe neurological defects, Type II also causes the spleen and liver enlargements seen in Type I. However, unlike Type I, it is not concentrated in the Ashkenazi Jewish ethnic group, and is not concentrated in any other specific ethnic group in particular. (1) .

Like Type II Gaucher Disease, Type III Gaucher, also known as Sub Acute Neuropathic Form, is also an exceptionally rare form. It usually strikes during childhood, and accounts for less than 5% of all Gaucher Disease cases. It is estimated that fewer than 1 in 100,000 live births worldwide (with the exception of Scandinavia) result in this type of the disease. While some patients afflicted with this type of Gaucher Disease die during their childhood, most others can live to middle age and some even beyond middle age (6) . This second neuronopathic form was also once called juvenile Gaucher disease, and progresses the most slowly of all three types. As is the case with Type II Gaucher Disease, Type III is not associated with a specific ethnicity, yet many Type III Gaucher sufferers have been found to be concentrated in Sweden (1) . Symptoms in the nervous system in patients who have this form of the disease include myoclonic seizures, a lack of coordination and mental degeneration. The form is more severe than Type I; like Type I, symptoms also include enlarged liver and spleen and bone disease. However, although it is neuronopathic, its effects on the nervous system are not nearly as drastic, rendering it less severe than Type III (4) .

The three forms of Gaucher Disease all result from a lack of the production of the glucocerebrosidase enzyme, and all have drastic effects on numerous body systems. Type I Gaucher is far less rare than the other two, is non-neronopathic and not so rare among Eastern European Jews. Conversely, the second two types of Gaucher are much rarer, are neuronopathic and panethnic, and the symptoms are much more severe than those exhibited in Type I .

References

WWW Sources

1)Living With Gaucher Disease, from Massachusetts General Hospital

2)Gaucher Disease in Ashkenazic Jews

3)The NTSAD Diseases Family: Gaucher Disease , from NTSAD

4)Gaucher Disease – Rare Disorders-Medstudent , from Medstudents.com

5) Scientific American:Ask the Experts: Medicine -
What is Gaucher Disease? Are there treatments? , from Scientific American

6) Health Topics A-Z: Gaucher Disease , from Ahealthyme.com


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