Sickle Cell Disease Symptoms and Genetics

Study Notes

Symptoms

Anemia: pale skin, weakness, fatigue, shortness of breath
Pain episodes (crises): acute, severe, and recurring pain in abdomen, chest, joints, or bones
Increased infections: pneumonia, meningitis, osteomyelitis
Delayed growth and development in children
Vision problems: retinopathy, blindness
Ulcers: painful sores on legs
Jaundice: yellowing of skin and eyes
Dark urine: increased bilirubin levels

Genetics

Autosomal recessive disorder: inherited from parents
Mutation in HBB gene: codes for hemoglobin subunit beta
HbS gene: abnormal hemoglobin that causes sickling of red blood cells
Carrier frequency: 1 in 12 African Americans, 1 in 100 Hispanics, 1 in 500 Caucasians
Inheritance patterns:
- Two copies of HbS gene: sickle cell anemia
- One copy of HbS gene: sickle cell trait (carrier)
- No copies of HbS gene: no sickle cell anemia or trait

Diagnosis

Newborn screening: mandatory in many countries
Hemoglobin electrophoresis: separates hemoglobin types
High-performance liquid chromatography (HPLC): measures hemoglobin levels
Molecular genetic testing: detects HBB gene mutations
Peripheral blood smear: examines red blood cell shape

Treatment Options

Pain management: medication, hydration, oxygen therapy
Antibiotics: prevent and treat infections
Folic acid supplements: prevent anemia
Blood transfusions: increase red blood cell count
Hydroxyurea: reduces frequency of pain episodes
Bone marrow transplant: curative treatment, rare

Complications

Acute chest syndrome: respiratory failure
Stroke: increased risk in children
Pulmonary hypertension: high blood pressure in lungs
Kidney damage: increased risk of kidney failure
Gallstones: increased bilirubin levels
Priapism: painful, prolonged erection
Increased risk of infections: pneumonia, meningitis, osteomyelitis

Symptoms

Pale skin, weakness, fatigue, and shortness of breath are symptoms of anemia
Acute, severe, and recurring pain in abdomen, chest, joints, or bones occurs during pain episodes (crises)
Increased risk of infections, such as pneumonia, meningitis, and osteomyelitis
Delayed growth and development are common in children with sickle cell anemia
Vision problems include retinopathy and blindness
Painful sores on legs are a common symptom of ulcers
Yellowing of skin and eyes (jaundice) and dark urine are signs of increased bilirubin levels

Genetics

Sickle cell anemia is an autosomal recessive disorder, inherited from parents
A mutation in the HBB gene, which codes for hemoglobin subunit beta, causes the condition
The HbS gene leads to abnormal hemoglobin production, causing sickling of red blood cells
Carrier frequency varies among populations: 1 in 12 African Americans, 1 in 100 Hispanics, and 1 in 500 Caucasians
Inheritance patterns determine the likelihood of developing sickle cell anemia or being a carrier

Diagnosis

Newborn screening is mandatory in many countries to detect sickle cell anemia
Hemoglobin electrophoresis separates hemoglobin types to identify abnormal hemoglobin
High-performance liquid chromatography (HPLC) measures hemoglobin levels
Molecular genetic testing detects HBB gene mutations
Peripheral blood smear examines red blood cell shape to identify sickling

Treatment Options

Pain management involves medication, hydration, and oxygen therapy
Antibiotics are used to prevent and treat infections
Folic acid supplements prevent anemia
Blood transfusions increase red blood cell count
Hydroxyurea reduces the frequency of pain episodes
Bone marrow transplant is a curative treatment, but rare

Complications

Acute chest syndrome is a respiratory failure complication
Children are at increased risk of stroke
Pulmonary hypertension leads to high blood pressure in lungs
Kidney damage increases the risk of kidney failure
Gallstones are a common complication due to increased bilirubin levels
Priapism is a painful, prolonged erection that can occur
Increased risk of infections, such as pneumonia, meningitis, and osteomyelitis, is a common complication

Description

Learn about the common symptoms of sickle cell disease, including anemia, pain episodes, and increased infections, as well as its genetic inheritance pattern. Test your knowledge of this genetic disorder.