Hemophilia
Incidence:
Hemophilia is a sex-linked disorder that affects males of all races and ethnic groups. About 1 in 4,000 males are born with the disorder. Females can have the disorder but it is significantly rare.
http://www.ygyh.org/hemo/whatisit.htm
Cause:
Hemophilia occurs when a person has a mutation in one of the clotting factor genes. Approximately 90% have a mutation in the Factor VIII gene (hemophilia A), 9% have a mutation in the Factor IX gene (hemophilia B), and 1% have a mutation in another clotting gene.
http://www.ygyh.org/hemo/whatisit.htm
Symptoms:
People with hemophilia bleed longer because their blood does not clot well. Without treatment, a person with severe hemophilia can bleed to death. With treatment, internal bleeding in the joints is the most problematic complication, because it leads to painful arthritis.
http://www.ygyh.org/hemo/whatisit.htm
Inheritance:
Hemophilia is like any other sex-linked disorder, because the "hemophilia gene is on the X chromosome. The X is one of two types of chromosomes - X and Y- that determine sex. A boy has an X chromosome and a Y chromosome. This "mismatch" in the sex chromosome of boys makes them more susceptible to disorders caused by genes on the X. A girl has two Xs and therefore, two factor genes. If one is mutated she can fall back on the other gene. A boy has only one X and one factor gene. If he has one mutated Factor gene, he has no other copy to fall back on.
http://www.ygyh.org/hemo/whatisit.htm
Treatment:
People with hemophilia inject themselves with purified clotting factors to prevent or stop bleeding episodes. Additional treatment is necessary if the persons immune system attacks the injected clotting factors.
http://www.ygyh.org/hemo/whatisit.htm
Testing and Screening:
A physician will use several blood tests to rule out other blood disorders before diagnosing hemophilia. The final test determines which factor is responsible and the factor's activity level. Genetic testing can uncover carriers and people with mild hemophilia.
http://www.ygyh.org/hemo/whatisit.htm
Sickle Cell Disease
Incidence:
Sickle cell disease is the most common single gene disorder in african americans, affecting one in every 375. Globally, a quarter of a million children are born with the disease each year, mainly in Africa, the Mediterranean, Arabia, and South Asia.
http://www.ygyh.org/sickle/whatisit.htm
Cause:
Sickle cell diseases include three distinct types. Sickle cell anemia, SC disease, and S[] disease. They are caused by a mutation in a blood protein called beta globin. The mutation leads to changes in the shape. and behavior of the red blood cells. The sickled, stiff and sticky red blood cells of sickle cell disease cause severe organ damage and intense pain.
http://www.ygyh.org/sickle/whatisit.htm
Symptoms:
Pain associated with blocked blood vessels is the most obvious symptom, and can be severe enough to warrant hospitalization. The blocked blood vessels frequently lead to spleen, lung, and heart damage and stroke. Sickle Cell also causes anemia, which leads to fatigue.
http://www.ygyh.org/sickle/whatisit.htm
Inheritance:
A person gets sickle cell disease when she inherits an S-type beta globin gene from one parent and a C-type gene from the other. The C-type is slightly different from the S-type, but both causes sickling.
http://www.ygyh.org/sickle/whatisit.htm
Treatment:
A bone marrow treatment is the only available cure, but it is a high risk operation. Although it has been successful in severely affected children, adults have a tendency to reject the transplant. The drug hydroxyurea helps to prevent or lessen sickle cell's complications; blood transfusions and narcotics for pain also help to alleviate the symptoms.
http://www.ygyh.org/sickle/whatisit.htm
Testing and Screening:
In mosts states, newborns are screened for hemoglobin disorders, including sickle cell. The screening test determines which hemoglobin types each each child makes. A child with sickle cell makes hemoglobin S instead of the usual hemoglobin A.
http://www.ygyh.org/sickle/whatisit.htm
Down Syndrome
Incidence:
Down syndrome is one of the most commonly occurring genetic birth defects, and it is the most common genetic reason for mental retardation. About one in 900 people are born with this disorder. Because of higher fertility rates in younger women, the majority of down syndrome are born to mothers under 35 years of age: however the likelihood of having a child with down syndrome increases with advancing maternal age.
http://www.ygyh.org/ds/whatisit.htm
Cause:
People with down syndrome have an excess, or redundancy of genetic material in their cells-spacifically, an excess of chromosome 21. The fast majority approximately 95%, have a complete extra chromosome 21. Others with down syndrome, 4% have an extra bit of chromosome 21 attached or "translocated" onto another chromosome - usually chromosome 14. And some, 1% have a mixed or "mosaic" pattern of cells in their bodies where some cells have normal amounts of genetic material and other cells have an extra chromosome 21.
http://www.ygyh.org/ds/whatisit.htm
Symptoms:
Children born with down syndrome vary widely in their symptoms. there most common symptoms include; mental retardation, an upward slant to the eyes, decreased muscle tone, flattened facial profile with depressed nasal bridge and small nose, small mouth and abnormal shape to the ears, and laxity around the body's joints.
http://www.ygyh.org/ds/whatisit.htm
Inheritance:
Most cases of down syndrome result from faulty gamete cell division and are not inherited. But a small percentage of those with Down did inherit chromosomal defect from either their mother or father.
http://www.ygyh.org/ds/whatisit.htm
Treatment:
There is no cure for down syndrome nor there are effective medical treatments at the present time. However, because of conditions common to those with down syndrome , such as heart defects, hears deficits, and developmental delays, good medical and supportive care is essential to this population.
http://www.ygyh.org/ds/whatisit.htm
Testing and Screening:
Prenatal testing can be done to determine if a fetus has down syndrome. Babies born with down syndrome usually have physical characteristics that lead to a suspicion of the disorder. Diagnosis is confirmed with a test called "karyotype" that gives a complete picture of an individual's chromosomes.
http://www.ygyh.org/ds/whatisit.htm
Alzheimer Disease
Incidence:
Age is the major risk factor for alzheimer disease (AD). It is the most common cause of dementia in people over 65. As many as 4 million Americans currently suffer from AD, and as the U.S population ages that number is expected to rise significantly. Some 10% of people of age 65 are afflicted with AD; of those age 85 or older the incidence increases to 50%.
http://www.ygyh.org/alz/whatisit.htm
Cause:
Alzheimer disease (AD) is characterized by progressive destruction and death of nerve cells in the brain. This leads to shrinkage or "atrophy" in certain regions of the brain and decrease in chemicals called neurotransmitters that ferry important messages between nerve cells. The result of these cell and chemical is a steady decline in mental function.
http://www.ygyh.org/alz/whatisit.htm
Symptoms:
People with AD have two distinct sets of symptoms; cognitive and behavioral. The severity of the symptoms increase over time. Cognitive symptoms; memory loss, disorientation, confusion, and difficulty with reasoned thought. Behavioral symptoms; agitation/anxiety, delusions/hallucinations, depression, insomnia, and wandering.
http://www.ygyh.org/alz/whatisit.htm
Inheritance:
While sporadic AD is not linked to an obvious pattern of inheritance, there is an associated risk of developing this form of AD tied to a version of APOE gene on chromosome 19. Having one version, or allele, of a gene can lead to an increased susceptibility to developing a disorder. People with the e4 allele of APOE are more likely to develop AD, but not everyone with APOE e4 will develop AD. The APOE gene we have is passed to us from our parents. Each parent contributes one allele of the APOE to his or her offspring.
http://www.ygyh.org/alz/whatisit.htm
Treatment:
Currently, there is no treatment that will stop or reverse the symptoms of alzheimer disease (AD). However, the Food and Drug Administration has approved the use of three drugs that attempt to slow the progression of the disease. These drugs work to maintain levels of critical message-sending in the brain called neurotransmitters.
http://www.ygyh.org/alz/whatisit.htm
Testing and Screening:
When people exhibit symptoms consistent, doctors perform test to exclude other causes of dementia or cognitive problems. If no other reason is found, a tentative diagnosis is made - a conclusive diagnosis of AD can only be made by direct examination of the patient's brain for characteristic plaques and tangles after death in an autopsy.
http://www.ygyh.org/alz/whatisit.htm
Age is the major risk factor for alzheimer disease (AD). It is the most common cause of dementia in people over 65. As many as 4 million Americans currently suffer from AD, and as the U.S population ages that number is expected to rise significantly. Some 10% of people of age 65 are afflicted with AD; of those age 85 or older the incidence increases to 50%.
http://www.ygyh.org/alz/whatisit.htm
Cause:
Alzheimer disease (AD) is characterized by progressive destruction and death of nerve cells in the brain. This leads to shrinkage or "atrophy" in certain regions of the brain and decrease in chemicals called neurotransmitters that ferry important messages between nerve cells. The result of these cell and chemical is a steady decline in mental function.
http://www.ygyh.org/alz/whatisit.htm
Symptoms:
People with AD have two distinct sets of symptoms; cognitive and behavioral. The severity of the symptoms increase over time. Cognitive symptoms; memory loss, disorientation, confusion, and difficulty with reasoned thought. Behavioral symptoms; agitation/anxiety, delusions/hallucinations, depression, insomnia, and wandering.
http://www.ygyh.org/alz/whatisit.htm
Inheritance:
While sporadic AD is not linked to an obvious pattern of inheritance, there is an associated risk of developing this form of AD tied to a version of APOE gene on chromosome 19. Having one version, or allele, of a gene can lead to an increased susceptibility to developing a disorder. People with the e4 allele of APOE are more likely to develop AD, but not everyone with APOE e4 will develop AD. The APOE gene we have is passed to us from our parents. Each parent contributes one allele of the APOE to his or her offspring.
http://www.ygyh.org/alz/whatisit.htm
Treatment:
Currently, there is no treatment that will stop or reverse the symptoms of alzheimer disease (AD). However, the Food and Drug Administration has approved the use of three drugs that attempt to slow the progression of the disease. These drugs work to maintain levels of critical message-sending in the brain called neurotransmitters.
http://www.ygyh.org/alz/whatisit.htm
Testing and Screening:
When people exhibit symptoms consistent, doctors perform test to exclude other causes of dementia or cognitive problems. If no other reason is found, a tentative diagnosis is made - a conclusive diagnosis of AD can only be made by direct examination of the patient's brain for characteristic plaques and tangles after death in an autopsy.
http://www.ygyh.org/alz/whatisit.htm