Genetic Diseases

(1)Sickle-cell anaemia鐮刀形紅血球貧血症

Introduction of Sickle-cell anaemia

It is a genetic diseases the patient’s red blood cells are rigid & sickle in s

hape common disaeses in African two copies of the haemoglobin gene in every cell

of our body a recessive condition because they have two copie

s of the sickle haemoglobin gene to have the disorder.

Problems of Sickle-cell anaemia

Less oxygen are be carried these sickle cell are weak and have shorter

life span lead to small blood vessels getting blocked lead to severe pain and damage to organs such as liver, kidney, lungs, heart and

spleen. Death can be a result.

Explaination of blocking blood vessels

The Genetic Combination (1)Sickle Cell Trait an

d Unaffected none of the children wi

ll have sickle cell anaemia.

a one in two (50%) chance that any given child will get one copy of the HbS gene and therefore have the sickle cell trait.

The Genetic Combination

(2) Sickle Cell Trait and Sickle Cell Trait

(25%) chance that any given child could be born with sickle cell anaemia.

(25%)chance that any given child could be completely unaffected

The Genetic Combination

(3) Sickle Cell Trait and Sickle Cell Anaemia

a one in two (50%) chance that any given child will get sickle cell trait and a one in two chance that any given child will get sickle cell anaemia.

The Genetic Combination

(4)Sickle Cell Anaemia and Unaffected

all the children will have sickle cell trait.

None will have sickle cell anaemia.

Genetic Diseases

(2) Haemophilia血友病

Introduction of Haemophilia

a lifelong inherited genetic disease Haemophilia (Greek)=“love of blood” Hemorrhaephilia=“The love of hemorrhage” (hemorrhage=bleeding) an essential clotting factor is either partly or

completely missing causes a patient to bleed for longer than nor

mal.

Threes types of Haemophilia

Haemophilia A (80%) lacks clotting factor 8

Haemophilia B(20%) lacks clotting factor 9

Haemophilia C lacks clotting factor 11

Why Haemophilia patient bleeding seriously For blood

clotting, 13 clotting

factors (protein),must be all present,blood can’t clot,even lack of one.

Levels of Haemophilia

First level of Haemophilia

5%~30% of clotting factors in blood

only get problem when serious injury or during operation.

(Cont’d)Levels of Haemophilia

Second level of Haemophilia 1%~5% clotting factors in blood regular bleeding(spontaneous) Third level of Haemophilia (severe) <1% clotting factors in blood bleeds cause acute pain and severe joint da

mage leading to disability

Causes of Haemophilia Inheritance the problem

gene(production of clotting factors) is in X chromosome

Most patients are Male

because they only got one X-chromosome

Causes of Haemophilia

Causes of Haemophilia

Acquired Haemophilia not born with haemophilia develop antibodi

es against one of the clotting factors such as factor 8

Pregnancy and autoimmune diseases such as rheumatoid arthritis and cancer may increase the risk of developing it(antibodies)

Treatments of Haemophilia

replacement of the missing clotting factor. injecting it on a regular basis (called

prophylaxis) to help prevent bleeding (Regular treatment )

injecting at the time a bleed occurs (called on-demand therapy)

no permanent way of replacing or increasing the clotting factor level.

Genetic Diseases

(3)G-6-P dehydrogenase Deficiency

葡萄糖 -6- 磷酸鹽去氫酉每缺乏症

Introduction of G-6-P Deficiency

glucose-6-phosphate dehydrogenase deficiency (favism)

is a hereditary abnormality in the activity of an erythrocyte (red blood cell) enzyme

lead to hemolytic anemia with jaundice following the intake of fava beans, certain legumes and various drugs

Inheritance of G-6-P Deficiency

Inheritance of G-6-P deficiency

The defect is sex-linked, transmitted from mother (usually a healthy carrier) to son (or daughter, who would be a healthy carrier. This is due to the fact that the structure of G-6-PD is carried on the X chromosome

Symptoms of G-6-P Deficiency

hemolytic anemia:feel tired, short of breath, have an irregular heart beat, and may have a dark orange urine.

This enzyme is essential for assuring a normal life span for red blood cells, and for oxidizing processes. This enzyme deficiency may provoke the sudden destruction of red blood cells and lead to hemolytic anemia with jaundice

Treatment of G-6-P deficiency

Avoid taking fava beans, certain legumes and various drugs e.g. Chloramphenicol

Blood transfusions when crisis appear

Conclusion

For the above three genetic diseases There is no cure for them thus to avoid these disease Genetic test should be done before

marriage