The Genetics of Sickle Cell Anaemia

By Katie Ridewood

What is Sickle Cell Anaemia? A disorder that effects haemoglobin Red blood cells are “sickle shaped”

Normal RBC – biconcave

Sickle cell

What’s the effect of this sickle shape?

How does it affect people? Anaemia Severe pain Damage to organs such as: Liver, Kidney,

Lungs, Heart & Spleen

How do you get Sickle Cell Anaemia?

Genetic disorder Incomplete recessive gene for the coding of

sickle haemoglobin. 2 recessive genes required to be sickle

cell. Sickle Cell trait

Inheriting Sickle Cell

Outcomes RR Both alleles coded

correctly No sickle cell anaemia

‘rr’ Both alleles coded for

incorrect haemoglobin Will suffer from sickle

cell anaemia Likely to die before 20.

Sickle Cell Trait Rr One allele for correct haemoglobin One allele for sickle cell haemoglobin Co-dominant

Sickle cell trait X “normal” Male: RR Female Rr

Eradication of Sickle Cell… 1 in 500 African Americans 1 in 100 Africans In Africa

0.000%

0.200%

0.400%0.600%

0.800%

1.000%

% of population

Africa America

Area

% Population developing Sickle Cell Anaemia

Series1

Sickle Cell Vs Malaria Parasites use red

blood cells as hosts Sickle cells die Parasites trapped Infection reduced

Gene Pool Homozygous “normal” haemoglobin Suffer from Malaria Homozygous sickle cells Suffer from Sickle Cell anaemia Heterozygous people Don’t suffer enough from either illness

Sickle Cell & Malaria

Bibliography & References www.sicklecellsociety.org http://www.lbl.gov/MicroWorlds/xfiles/malariawhati

s.html http://chroma.gs.washington.edu/outreach/genetic

s/sickle/sickle-back.html http://www.wellesley.edu/Chemistry/Adele/Chem2

22/Syllabus/Links/bindprotns/malaria.html http://www.lbl.gov/MicroWorlds/xfiles/

malariawhatis.html