MODY Flashcards
What does MODY stand for?
Maturity Onset Diabetes of the Young
What are the most common types of MODY?
- Glucokinase mutation MODY
- Transcription factor MODY
- MODY X
What is glucokinase and what does it do?
Enzyme
Phosphorylates glucose to glucose-1-phosphate
Why is a mutation in the glucokinase gene an issue for people with MODY?
Abnormal GLUT2 function and glucokinase is less responsive to glucose
GCK-MODY is a progressive condition
True or false?
False
It is non-progressive
Transcription factor MODY most commonly affects which genes?
- HNF1A
- HNF4A
- HNF1B (rarer)
What is MODY X?
MODY with no proven/provable cause
Transcription factor MODY is progressive
True or False?
True
It is a progressive condition
Generally patients with MODY require insulin
True or false?
False
Although they may require it later on in life
How do patients with MODY generally present?
- Strong family history of diabetes
- Onset of diabetes in the 2nd to 5th decade
- Insulin independence
- Absence of B cell autoimmunity
- Absence of insulin resistance features
What are the key signs of insulin resistance?
- Acanthosis nigricans
- Abnormal fat distribution
- Central obesity
- Dyslipidaemia (abnormal fat (triglycerides or LDL) in the blood)
Patients with GCK-MODY have a _________ threshold for the initiation of glucose stimulated insulin secretion
Patients with GCK-MODY have a raised threshold for the initiation of glucose stimulated insulin secretion
Due to having a raised threshold for insulin secretion, patients with GCK-MODY have a lifelong what?
Mild, stable hyperglycaemia
How will a patient’s blood sugar levels change if they have GCK-MODY?
Low rise
What are patients with HNF1A and HNF4A mutations at risk of?
Microvascular and macrovascular consequences of diabetes
What is MODY often diagnosed as?
Type 1 diabetes
If a patient is misdiagnosed with type 1 diabetes, yet actually has MODY, how may this be shown after 3-5 years post-diagnosis?
- Continued endogenous insulin secretion
- Persistent C-peptide
- No tendency to ketoacidosis
How can C-peptide be measured?
Urine or blood
Urine is easier as the C-peptide to creatinine ratio can be measured
Usually patients with MODY do not have which characteristic thing of type 1 diabetes?
Pancreatic autoantibodies
What is the first line treatment for HNF1A and HNF4A MODY?
Sulphonyureas
(low doses, these agents are very effective in this type of MODY)
What is the first line treatment for GCK-MODY?
Nothing
In children with severe hyperglycaemia what treatment is given?
Insulin
This is the safest thing to do, despite there being a chance the child has MODY
If a pregnant women has asymptomatic hyperglycaemia secondary to GCK-MODY, what man she present with?
Gestational diabetes
What is the treatment for a pregant woman with GCK-MODY?
Insulin
(if there are signs foetal development may be impacted)
What is the first line treatment for a pregant woman with HNF1A/HNF4A MODY?
Glibenclamide (a sulphonyurea)
