autosomal recessive diseases

 Autosomal Recessive Disease

Autosomal recessive disease are;

1. Phenylketonuria 

2. Wilson's disease

3. Cystic fibrosis

4. Sickle cell anemia

5. Tay-sachs disease

6. Galactosemia; disorders of carbohydrate metabolism

7. Diastrophic dysplasia

8. Thalassemia

9. Inborn error of metabolism; lysosomal storage disease

Autosomal Recessive Inheritance

To have autosomal recessive disorder, inherit two mutated genes, one from each parent.

Inheritance;

2 parent affected; 50% of off spring carrier, 25% affected and 25% healthy.

50% chance that child is born with one normal and one abnormal gene carrier without disease.

25% chance that child born with two abnormal gene (at risk of disease)

25% chance that child born with two normal genes (normal).

For example, 

Father (father is carrier)     Mother (mother as carrier)

✓X, ✓X.   ✓; working gene,  X; non working gene

✓✓; child doesn't have condition, not carrier) 25% healthier

✓X; children doesn't have condition, but carrier 

X✓; children doesn't have condition, but carrier 

XX; child has condition, 25% have the condition

              

For example; 

22AA + XX/XY

(22 pair autosome + 1 pair chromosome) 

Autosomes (gene located on non sex chromosome)

Aa (Father)               Aa (Mother)

AA; will not get disease

Aa; not disease

aA; not disease

aa; both faulty copy (disease)