Complex genetic diseases: Obesity Flashcards
What is complex disease?
It has genetic and environmental components
What do all forms of monogenic forms of obesity affect?
Appetite REGULATION
What are the 3 types of obesity?
Syndromic, Monogenic and Common
What is syndromic obesity commonly accompanied by and give an example?
Mental Retardation & Dysmorphic or clinical features
Example: Prader-willi syndrome
What is leptin?
- Hormone
- It is a signalling molecule that is produced by adipose tissue
- Moves through the circulatory system to the brain to tell how much fat store is in the body
- More fat=more leptin
- high leptin tells the brain that you do not need to eat more food
- Leptin also stimulates the onset of puberty
- before puberty there is a build up of fat, which sends a permissive signal via leptin to the brain to tell it that puberty can begin
Describe the action of leptin.
Leptin is produced by adipocytes and travels to the brain to let the brain know how much fat is stored in the adipose cells and thus regulates feeding
What are some features of leptin deficiency?
- Uncontrollable appetite
- Incomplete/lack of puberty
- low thyroid function and immune problems
What is the treatment for leptin deficiency?
Recombinant leptin
What do most fat people have that causes obesity?
Leptin deficiency is rare.
Fat people have an insensitivity to Leptin.
What regulates body fat levels
The leptin-melanocortin adipostat
What other genes in the same pathway can cause monogenic obesity
Dominant:
-MC4R: most common single-gene form of obesity
Recessive
- PCSK1: obesity
- POMC: red hair, obesity, adrenal insufficiency
- MRAP2: obesity
All of these affect appetite regulation
What are Genome Wide Association Studies used for in relation to obesity?
To identify single nucleotide polymorphisms that are associated with obesity e.g. FTO
