Zusammenfassung der Ressource
Sickle Cell Anaemia
- Phenotype first described by James Herrick
- Symptoms
- Fatigue, shortness of breath, paleness
- Pain
- Infections
- Enlarged spleen
- Sores that don't heal
- Stroke
- Eye problems
- Red blood cells change their shape to
squeeze through the smallest capillaries.
- Sickled Cells
can clump and
block
capillaries
- Treatment for Sickle Cell Disease
- Antibiotics taken daily
- Pain management
- Prevention of
complications
- Blood transfusions
- If genes code
proteins, then what
is the defective
protein in Sickle
Cell Anaemia?
- Hemoglobin
- Made up of 2
alpha globins and
2 beta globins
- Globins
- Long chains of amino acids
- The gene that
causes Sickle Cell
Anaemia encodes
beta-globin
- The beta-globin gene is on
chromosome 11
- An autosomal recessive trait
- How common is Sickle Cell Anaemia?
- Sickle Cell Anaemia among Afro-Americans
- ~1 in 400 are born with Sickle Cell Anaemia
- 1 in 10 are carriers
- The sickle cell allele is associated with malaria
- Malaria
- 300-500 million cases per year
- 1.5-2.7 million deaths per year
- In Africa
- 1 million children (<5 years) die per year
- 2800 children die per day
- Many died of malaria in WW2
- Clinical Symptoms
- Chills: intense cold feeling, shivering, nausea, vomiting
- 1/2 - 1 hour later, hot stage: high fever, mild delirium; can last for several hours
- Fever breaks: copious perspiration, temperature normal after 2-3 hours
- Plasmodium Falciparum
- Causes malignant tertian malaria
- Fever and chills every 48 hours
- Responsible for 95% of malaria deaths worldwide
- Malignant forms of falciparum malaria:
- Bilious remittant fever: nausea,
jaundice, urine with bile pigment, high
fever, vomiting
- Cerebral malaria: headache, very
high fever, convulsions, coma,
death can occur very quickly
- Algid malaria: skin cold and
clammy, bloody vomiting, bloody
stools
- Blackwater fever: massive
lysis of RBCs, blood in urine,
kidney failure
- Plasmodium
- Develops in the gut of the mosquito
- Migrates to the salivary glands of the mosquito
- Enters the human bloodstream when a mosquito feeds
- Invades RBCs
- Multiplies and destroys RBCs
- Invades new RBCs or liver cells
- Heterozygotes are resistant to falciparum malaria