Complex genetic diseases Flashcards
What are the three forms of obesity?
Syndromic
Monogenic
Common
What causes monogenic obesity?
A deficiency in leptin
What is leptin responsible for?
Blood-borne factor responsible for controlling appetite.
Causes reduced food-intake, insulaemia and blood sugar
What do leptin levels indicate?
How much fat in blood
Thus, is proportional to amount of adipose tissue
Which other genes lead to monogenic obesity?
MC4R - DOM
PCSK1
POMC - all REC
MRAP2
What is a form of syndromic 0obesity?
Prader Willi - imprinting defect - paternal or maternal?
What are the different forms of diabetes?
Monogenic
MODY - maturity onset diabetes in the young
PND - permanent neonatal diabetes
Polygenic
Types 1 & 2
What causes MODY?
Defective genes - AUTOSOMAL DOMINANT: absence of
- Glucokinase - protein is enzyme
- HNF-4alpha - protein is TF
- HNF-1alpha and beta - protein is TF for insulin
What causes Type 1 diabetes and describe it
Diminished or absent beta cell function
DUE TO AUTOIMMUNE RESPONSE
Replace insulin
What causes Type 2 diabetes and describe it
Resistnace to insulin - bad diet etc
Requires insulin if diet changes are not enough
Essentially too much insulin is made and less secreted towards end
What is heritability?
Study of genetic contribution to increased risk of disease
How can heritability be studied?
Hard as many factors, both genetic and lifestyle, so study twins and relatives
What are genome-wide association studies?
Studies used to see if disease is statistically associated with SNPs
single nucleotide polymorphism
What was seen to be affected in type 2 diabetes from GWAS?
Beta cell function
What are the uses of GWAS?
Genetic risk scoring and personalised treatment
