medicine and nursing, health and medical assignment help

User Generated

CEBS YRVAFGRVANEQ

Health Medical

Description

presentation on sickle cell anemia

User generated content is uploaded by users for the purposes of learning and should be used following Studypool's honor code & terms of service.

Explanation & Answer

Attached.

SICKLE CELL DISEASE
kibaru

OUTLINE
 Describe

the genetics of sickle cell

disease
 Outline

the crises associated with
sickle cell disease

 What

are organ involvement in
sickle cell disease

EPIDEMIOLOGY
Incidence
 Sickle hemoglobin is the most common abnormal
hemoglobin found in the United States




approximately 8% of the African-American
population has sickle cell trait.
The expected incidence of sickle cell disease
(SCD) at birth is 1 in 625.

NORMAL VS. SICKLE RED CELLS

Sickle

Normal
Disc-Shaped
 Deformable
 Life span of 120 days


Sickle-Shaped
 Rigid
 Lives for 20 days or
less


GENETICS




Sickle cell disease is transmitted as an
autosomal recessive trait.
Homozygotes (two abnormal genes) do not
synthesize hemoglobin A (HbA)




red cells contain 90–100% hemoglobin S (HbS).

Heterozygotes (one abnormal gene) have red cells
containing 20–40% HbS

SICKLE CELL PEDIGREE

 Parents

with sickle cell trait: hemoglobin AS
 Probability of child with hemoglobin AA: 25%
 Probability of child with sickle cell trait AS: 50%
 Probability of child with sickle cell disease SS:
25%



HbS arises as a result of spontaneous mutation
and deletion of the β-globin gene on chromosome
11


which results in selective advantage against

Plasmodium falciparum malaria in carriers
(balanced polymorphism).

CO-INHERITANCE






. α-Thalassemia (frequency of 1–3% in African
Americans) may be co-inherited with sickle cell
trait or disease.

Individuals who have both α-thalassemia and
sickle cell anemia are less anemic than those who
have sickle cell anemia alone.
However, α-thalassemia trait does not appear to
prevent frequency or severity of vaso-occlusive
complications.

CLASSIFICATION


Results of DNA polymorphism linked to the βs
gene suggest that it arose from three independent
mutations in tropical Africa:
1. Benin–Central West African haplotype (the most
common haplotype)
 2. Senegal–African West Coast haplotype
 3. Bantu–Central African Republic (CAR) haplotypen
southwest Saudi Arabia.




In Caribbean and North American patients of African
heritage



with SCD,
50–70% of chromosomes are Benin
▪ 15–30% are Bantu-CAR
▪ 5–15% are Senegal.






The Benin and Senegalese patients have higher
levels of fetal hemoglobin (HbF) and fewer dense
cells compared with Bantu-CAR patients.
Patients with Senegal haplotype have the least
severe disease, whereas patients with BantuCAR haplotype have most severe disease.

PREVALENCE/I...


Anonymous
Excellent resource! Really helped me get the gist of things.

Studypool
4.7
Trustpilot
4.5
Sitejabber
4.4

Similar Content

Related Tags