Flashcards in Diabetes Deck (17):
What causes MODY (maturity onset diabetes of the young)?
Autosomal dominant mutation
HNF 1alpha (most common)
Glucokinase (second most common)
what is HNF 1alpha?
Transcription factor that stimulates insulin production
Mutation = insulin production decreases in adulthood when its function naturally deteriorates
(appears in teenage years)
Treatment for HNF 1alpha MODY
Metformin = cells more sensitive to insulin
Sypulphonylurea = stimulates pancreas to produce more insulin by forcing potassium channel to close
What is glucokinase MODY?
Enzyme converts glucose - G6P
Higher glucose conc needed for insulin secretion to occur
Patients have stable mild hyperglycaemia
not associated with long term complications
Similar to HNF1alpha but rarer
Low renal glucose threshold
Renal cysts and diabetes
Genital tract mutation
What mutation causes Permanent neonatal diabetes
1 in 400000 births
Diabetes in first 6 months
How does the mutation cause permanent neonatal diabetes
KNCJ11 causes K+ channel to open when ATP is made by respiration
This means membrane cannot be depolarised and insulin not released
How do sulphonylureas treat PND?
Close the K+ channel so signal sent to insulin to be released
What is Sanger sequencing?
Sequences all exons of one single gene
Used to identify unknown mutation
But expensive, time consuming, poorly automated
What is next generation sequencing?
Sequences multiple genes
Used to identify mutations in multiple genes for heterogenous phenotypes
Not very accurate, needs a lot of data to sequence
What is pathogenicity?
Ability for an organism to cause disease
Symptoms of maternally inherited diabetes and deafness (MIDD)
Young onset deafness
What is polygenic diabetes?
Type 1 and 2
There must be a second hit to get condition e.g. environmental
What is GWAS?
Genome wide association study
Study to see if diseases is associated with single nucleotide polymorphism
Why could be causing the diabetes T2 epidemic?
Copy number variation (deletion and duplication of genes)= copies of the same gene