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Handbook of Genetic Counseling/Sickle Cell Anemia
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Sickle Cell Anemia
Introduction
Determine what the patient already knows about sickle cell
Assess what concerns the patient wants to address today
Elicit Medical History
Elicit Family History and Pedigree
What is sickle cell disease?
inherited blood disorder affecting the oxygen carrying part of the blood cells called hemoglobin
hemoglobin in sickle cell anemia forms a "sickle" or banana shape
normal hemoglobin is called hemoglobin A
sickle cell hemoglobin is called hemoglobin S
this shape causes it to be broken down in the liver leading to not enough blood cells
people with sickle cell disease experience pain, damage to organs, and sometimes early death
this is due to sickle shaped blood cells blocking tiny blood vessels
this leads to prevention of blood flow to certain areas of the body
Diagnosis
diagnosis is made by a blood test called hemoglobin electrophoresis
those with mostly hemoglobin S have sickle cell disease
those with only hemoglobin A do not have sickle cell disease
those with both hemoglobin A and hemoglobin S are heterozygote carriers and have sickle cell trait
this means they are carriers of the sickle cell gene
they generally do not have any health problems but can pass the gene to their children
this test requires 3cc of blood in a red-capped EDTA tube
prenatal testing is also available
in Ohio children are now tested for sickle cell as part of the newborn screening program
Symptoms
chronic hemolytic anemia - may lead to reduction in energy and cause growth retardation
Vaso-occlusion - blockage of small blood vessels that may lead to pain and tissue damage.
Splenic sequestration - increase in spleen size due to storage of red blood cells
Organ failure - may result from insufficient blood flow later in life
other problems may arise such as neurological effects, stroke, chronic eye disease, renal disease, and leg ulcers
Treatment
mainly symptomatic
drugs such as hydroxyurea are used to increase fetal hemoglobin
vasodilators and lubricants used to prevent microvascular blockage with very little success
John https://www.thestackerz.com/hemolytic-anemia-types-causes-symptoms-treatment/ What is Hemolytic Anemia? thestackerz.com 10 June 2023 10 June 2023
Inheritance
Sickle cell disease is inherited in an autosomal recessive fashion
people with sickle cell disease have two copies of the mutated gene
people with sickle cell trait have one normal gene and one mutated gene
Parents who both have sickle cell trait will have a 25% chance of having a child with sickle cell disease, a 50% chance of having a child with sickle cell trait, and a 25% chance of having a normal child who is not a carrier
If one parent has sickle cell disease and one parent has sickle cell trait, they have a 50% chance of having a child with sickle cell disease but the child will have sickle cell trait.
If one parent has sickle cell disease and the other parent is normal the child will have sickle cell trait but 0% chance of having sickle cell disease.
Clarification: In order for a child to have sickle cell disease both parents must have at least one copy of the abnormal sickle cell gene, or in other words both parents must have sickle cell trait for the child to have sickle cell disease.
Population Genetics
African-Americans: 1/12 are carriers
1/400-600 children are born with sickle cell disease
People of Hispanic, Greek, Italian, Arabic, and Asian Indian also have high carrier rates
Psychosocial Issues
Guilt over passing on trait to children
people with sickle cell trait may be treated as though they are sick despite having no symptoms
people with sickle cell trait may also be more worried about their health despite having no symptoms
worry over reproductive decisions
Resources
CHMC Cincinnati Comprehensive Sickle Cell Center
513-636-4541
333 Burnett Avenue
Cincinnati, OH 45229
The Ohio Sickle Cell Affected Families Association, Inc.
141 Tishman Street
Columbus, OH 43228
614-272-1516
National Association for Sickle Cell Disease, Inc.
3345 Wilshire Blvd., Suite 1106
Los Angeles, CA 90010-1880
213-736-5455
800-524-7802
References
Headings, Verle E. "Psychosocial Issues in Sickle Cell Counseling" Genetic Counseling: Psychosocial Dimensions. 1979.
March of Dimes Public Health Education Information Sheet. Sickle Cell Disease.
Koshy, Mabel. "Sickle Cell Disease" University of Chicago
Ricknagel, D. "Sickle Cell Syndromes"
Notes
The information in this outline was last updated in 2002.