What type of allele causes CF - whats its job?
Homo Recessive
Codes for CFTR protein
What chrosome is affected by CF
7
Why does a gene mutation to chrom 7 cause CF?
CFTR protein is non functional
Cl- cannot diffuse out of the alevolar cells
Water potential isnt decreased, so no water is drawn out the cell
Mucus isnt diluted, ciliated epithelum cannot waft it up.
What is CF
When thick mucus builds up in the lungs and pancreas
What is the treatment for CF
- Daily physiotherapy
- Pancreatic enzymes
- Antibiotics
- Fertility treatment
- Oxygen support
What is phenylketonuria
Its a deficiency of phenylalanine hydroxylase enzyme
What is the role of phenylalanine hydroxylase enzyme ?
To catalyse the conversion of
Phenylalanine
to
Tyrosine
which goes to
Melanin
Why is phenylalanine harmful?
It accumulates in blood and tissue fluid causing severe brain damage in young children
What is Huntington’s disease?
Accumulation of huntingtin protein fragments causing severe neuronal damage - neurone death and inabiloty of neurones to send impulses
What mutation causes Huntington’s?
Insertion
What chromosome is affected by Huntington’s?
Chromome 4
What allele causes Huntingtons?
Autosomal dominant
What is sickle cell anaemia?
The result of erythrocytes forming a sickle shape, which limits o2 carrying capacity - causing anemia
What mutation causes Sickle cell?
Substituion
What chromosome is affected by Sickle cell?
Chromosome 11
How does a mutation cause sickle cell?
Glutamic acid —–> valine
Affects the beta chains in Hb
Sickle cell shaped
Dec O2 carrying capacity
Is there any benefit of sickle cell?
Yes,
It provides resistance against malaria as the Plasmodium cannot live and reproduce inside host cells.
What is Duchenne muscular dystrophy?
- weakening of muscular contraction until paralysis occurs
What causes DMD?
Protein dystrophin is truncated
Needed for musclar contraction
What allele causes DMD?
Recessive
What chromosome is affected by DMD?
X chromosome
- sex linked
What are HLA antigens?
- the antigens on cam
A,B,C = major
E,F,G = minor - chromosome 6
What letter represents the haemoglobin gene and alleles for sickle cell?
H is the Hb gene
A = Sufferer
S = normal
Whay letter represents blood group antigen ?
I = csm antigen gene
