thalassemias

Question 1

What kinds of Hb are present in adults?

Answer 1

HbA 97% 2beta 2alpha
HbF 1% or even less 2alpha 2gamma chains
HbA2 2-3% 2alpha 2delta chains

Question 2

When people have qualitative Thalassemia what other kinds of Hb may they carry

Answer 2

HbD/E/C or sickle cell anaemia for example

Question 3

What is HbE and why is this persistant?

Answer 3

this is when a Glutamate in the beta Hb chain is replaced by a Lysine this results in defective beta Hb but has been able to persist particularly in the SE Asia population because it confers resistance to malaria.

Question 4

where are the alpha globin genes?

Answer 4

on the alpha globin locus close together on chromosome 16

Question 5

What is HbBarts?

Answer 5

this is when there are excess gamma chains in a new born due to their being a Hb Alpha thalassemia. This results in the formation of a gamma tetramer that has too high an affinity for oxygen to be functional

Question 6

Why is HbH disease often mistaken for Iron deficiency anaemia?

Answer 6

because there are microcytic red blood cells (low MCV) which however this can be cancelled out because you can then check serum total binding iron capacity and ferritin levels to prove that Fe levels are normal

Question 7

What is alpha Thalassemia major?

Answer 7

the loss of all four alpha HB genes resulting in Hydrops Fetalis –> most likey leading to the death of the fetus unless you can give in uterine blood transfusions.

Question 8

what are the symptoms of Alpha thalassemia? particularly HbH disease?

Answer 8

pallor, weakness, tiredness, jaundice, gallstones, pronounced forehead, hypertensions, hepatosplenomegaly

Question 9

how do you treat alpha thalassemia?

Answer 9

gallstones surgery and also blood transfusions

Question 10

what regions are the beta thalassemias most common?

Answer 10

the med, SE asia, african americans

Question 11

which thalassemias result in compensatory large liver and spleen?

Answer 11

the thalassemia major of beta thalassemia
and the HbH disease of the alpha type
sickle cell just a large spleen

Question 12

what are the symptoms of beta thala major?

Answer 12

fatigue, failure to thrive, juandice, hepatosplenomegaly, hypochromic microcytic red cells, expanded jaw due to boen extension and also reoccuring infections.

Question 13

how is beta thala major treated?

Answer 13

every 4-6 weeks with a blood transfusion

Question 14

What become reoccurent in beta thalassemia intermedia?

Answer 14

gall stones and ulcers

Question 15

What is the risk when you are constantly having blood transfusions?

Answer 15

Infection in Less developed countries
Fe overload
which accumulates in the heart, endocrine tissue and the pancreas.

Question 16

What is the life expectancy with a major beta thalassemia?

Answer 16

20 because of the cardiac damage and due to the impaired erythropoiesis from the alpha precipitates

Question 17

how is beta thala major treated?

Answer 17

blood transfusions early on to limit damage to the heart pancreas and the liver
with a deferoxamine chelator to try and hold back some of the Fe although this does have side effects like cataracts
as well as folate supplement if the person then lives to the age of 15 a bone marrow transplant may be offered this is the only change of a cure

Question 18

how is the development of a child affected by beta thala?

Answer 18

the child will have stunted growth and delayed puberty.

Question 19

How is sickle cell anaemia treated?

Answer 19

by blood transfusion
staying hydrated
aspirin tp acetylate the beta chain to prevent the release of Oxygen to stop t he sickling
prompt treatment of infection
fast action id there is a vasoolcclusive crisis
also bone marrow transplantation