DEFINITIONS What is anemia? Anemia is a lack of hemoglobin, the red coloring matter of blood. Hemoglobin supplies all of the body tissues with oxygen. What is Sickle Cell Anemia? Sickle Cell Anemia is an inherited abnormal blood condition which occurs predominantly in Black people. There are two forms of Sickle Cell Anemia - Sickle Cell Disease and Sickle Cell Trait.* The red blood cells contain an abnormal hemoglobin called Hemoglobin S which causes them to take on an abnormal shape resembling a sickle. These sickled cells have a much shorter life span than normal cells because they are rapidly destroyed. The rate of destruction exceeds the rate of production and thus anemia results. The destruction of the red cell is called hemolysis. Therefore, we say SCA is a hemolytic anemia. normal red cells Fig. 1 sickled red cells What is Glucose 6-Phosphate Dehydrogenase Deficiency? This too, is an inherited abnormality of the red blood cells. The abnormality is due to a lack of Glucose 6-Phosphate Dehydrogenase (G6PD). G6PD is an enzyme essential for the normal functioning of the red blood cells. When exposed to certain drugs the abnormal cells become leaky. Water enters the cells causing them to burst. This destruction is also called hemolysis. Thus, G6PD Deficiency is a hemolytic anemia also. What is a carrier? A seemingly healthy person who carries an inherited defect that can be passed on to his children is called a carrier. A. A. Carrier of Sickle Cell Trait An individual who carries both the normal hemoglobin (Hemoglobin A) Carrier of G6PD Deficiency All carriers of G6PD Deficiency are women! However, all women *See Appendix ETIOLOGY What causes Sickle Cell Disease? When two carriers of Sickle Cell Trait marry, 25%, or 1 out of 4, of their children could have Sickle Cell Disease. That is, at each pregnancy there will be a 25% chance of the child having Sickle Cell Disease. This is illustrated by the family tree in Fig. 2. There are approximately 60,000 persons in the United States with Sickle Cell Disease. Ten percent of the Black population, 2.5 million persons, are carriers. 71-519 O-72-8 ос Fig 2 mother 25% male female carrier of sickle cell trait sickle cell disease normal What causes G6PD Deficiency? A carrier for the G6PD defect who marries a normal male can pass the defect to a daughter producing another carrier or to a son producing an affected individual. This disease is prevalent among Black American males with 13% of them being affected. Another possibility is for a carrier to marry an affected male. Fifty percent of their daughters could have G6PD Deficiency because they have a defective gene on both X-chromosomes, the one from the father and the one from the mother (See Fig.3) This situation is very rare and only 3% of Black American females have G6PD Deficiency. carriers have a one-in-four chance at each pregnancy of hav Fifty percent of the off ing a child with Sickle Cell Disease. Males can only receive G6PD Deficiency from their mothers. are never carriers. Males Whenever they have the defect they are af fected and will suffer symptoms when exposed to certain drugs. Females can be carriers or they can receive the defect from both parents and be affected. Generally the female carrier suffers no symptoms, however, there are some exceptions. The female receiving the defect from both parents will be affected in a manner similar to the affected male. The affected female is very rare. Approximately 3% of Black female population is affected in the United States. SYMPTOMS What symptoms does the person with Sickle Cell Disease have? Persons with Sickle Cell Disease (SCD) are a lot like people with other types of anemias. They are usually short of breath and tire easily and they may have an enlarged heart due to the increased work placed on the heart by the lingering anemia. However, the person with Sickle Cell Anemia has an abnormal hemoglobin which causes the red blood cells to assume an abnormal shape. These sickled cells jan the small blood vessels. This jamming cuts off the blood supply to the body tis sues causing joint, stomach, back and bone pain; destruction of bone; rupture of small blood vessels causing frequent nose bleeds and even strokes; and an increas ed susceptibility to infection. What is a "Crisis"? When the sickling increases, the blood vessels become more jammed and therefore the symptoms become worse. Doctors call this a "crisis". Crises begin to occur early in life. The first may occur anywhere between the first four months and the first two years of life. They recur days, weeks or months apart for the rest of the person's life. These "crises" are characterized by very severe pain of joints, back, stomach and bones with fever. They last from several hours to several days. What are the symptoms of G6PD Deficiency? The person with G6PD Deficiency is free of symptoms until exposed to certain drugs. Upon exposure to drugs such as aspirin, antimalarials and antibiotics, symptoms and signs common to all hemolytic anemias develop; these are: we akness, yellow color of the white of the eyes and dark urine. In severe cases there may be stomach and back pain. These symptoms begin abruptly after exposure to the drug and end in about a week even though exposure to the drug may continue. The symptoms can be prevented entirely by avoiding exposure to the harmful drugs. Unlike Sickle Cell Disease, the symptoms of G6PD Deficiency can present as early as the tenth day of life. |