MODY

Question 1

What does MODY stand for?

Answer 1

Maturity Onset Diabetes of the Young

Question 2

What are the most common types of MODY?

Answer 2

1. Glucokinase mutation MODY
2. Transcription factor MODY
3. MODY X

Question 3

What is glucokinase and what does it do?

Answer 3

Enzyme

Phosphorylates glucose to glucose-1-phosphate

Question 4

Why is a mutation in the glucokinase gene an issue for people with MODY?

Answer 4

Abnormal GLUT2 function and glucokinase is less responsive to glucose

Question 5

GCK-MODY is a progressive condition

True or false?

Answer 5

False

It is non-progressive

Question 6

Transcription factor MODY most commonly affects which genes?

Answer 6

1. HNF1A
2. HNF4A
3. HNF1B (rarer)

Question 7

What is MODY X?

Answer 7

MODY with no proven/provable cause

Question 8

Transcription factor MODY is progressive

True or False?

Answer 8

True

It is a progressive condition

Question 9

Generally patients with MODY require insulin

True or false?

Answer 9

False

Although they may require it later on in life

Question 10

How do patients with MODY generally present?

Answer 10

1. Strong family history of diabetes
2. Onset of diabetes in the 2nd to 5th decade
3. Insulin independence
4. Absence of B cell autoimmunity
5. Absence of insulin resistance features

Question 11

What are the key signs of insulin resistance?

Answer 11

1. Acanthosis nigricans
2. Abnormal fat distribution
3. Central obesity
4. Dyslipidaemia (abnormal fat (triglycerides or LDL) in the blood)

Question 12

Patients with GCK-MODY have a _________ threshold for the initiation of glucose stimulated insulin secretion

Answer 12

Patients with GCK-MODY have a raised threshold for the initiation of glucose stimulated insulin secretion

Question 13

Due to having a raised threshold for insulin secretion, patients with GCK-MODY have a lifelong what?

Answer 13

Mild, stable hyperglycaemia

Question 14

How will a patient’s blood sugar levels change if they have GCK-MODY?

Answer 14

Low rise

Question 15

What are patients with HNF1A and HNF4A mutations at risk of?

Answer 15

Microvascular and macrovascular consequences of diabetes

Question 16

What is MODY often diagnosed as?

Answer 16

Type 1 diabetes

Question 17

If a patient is misdiagnosed with type 1 diabetes, yet actually has MODY, how may this be shown after 3-5 years post-diagnosis?

Answer 17

1. Continued endogenous insulin secretion
2. Persistent C-peptide
3. No tendency to ketoacidosis

Question 18

How can C-peptide be measured?

Answer 18

Urine or blood

Urine is easier as the C-peptide to creatinine ratio can be measured

Question 19

Usually patients with MODY do not have which characteristic thing of type 1 diabetes?

Answer 19

Pancreatic autoantibodies

Question 20

What is the first line treatment for HNF1A and HNF4A MODY?

Answer 20

Sulphonyureas

(low doses, these agents are very effective in this type of MODY)

Question 21

What is the first line treatment for GCK-MODY?

Answer 21

Nothing

Question 22

In children with severe hyperglycaemia what treatment is given?

Answer 22

Insulin

This is the safest thing to do, despite there being a chance the child has MODY

Question 23

If a pregnant women has asymptomatic hyperglycaemia secondary to GCK-MODY, what man she present with?

Answer 23

Gestational diabetes

Question 24

What is the treatment for a pregant woman with GCK-MODY?

Answer 24

Insulin

(if there are signs foetal development may be impacted)

Question 25

What is the first line treatment for a pregant woman with HNF1A/HNF4A MODY?

Answer 25

Glibenclamide (a sulphonyurea)