MODY - monogenic diabetes

Question 1

What is MODY ?

Answer 1

An autosomal dominant form of diabetes accounting for 3% of those diagnosed < 30

Question 2

What are the 2 different forms of MODY?

Answer 2

1. Transcription factor mutations - esp HNF-α
2. Glucokinase (GCK) mutations

Question 3

Describe the characteristic features of GCK MODY

Answer 3

• Onset at birth
• Stable hyperglycaemia (doesn’t get worse as they get older)
• Only diet required to treat it
• Complications are rare

Question 4

Describe the characteristic features of HNF-α (transcription factor) MODY

Answer 4

Adolescence/young aduly onset

Progressive hyperglycaemia

Treatment = 1/3rd diet, 1/3rd oral hypoglycemic agents (OHA), 1/3rd insulin

Complications frequent

Question 5

Compare the OGTT of GCK and HNF MODY

Answer 5

Question 6

What is the best treatment option for someone with HNF-α mutation causing MODY?

Answer 6

Sulphonylureas

Question 7

What are the 2 main types of neonatal diabetes?

Answer 7

• Transient neonatal diabetes (TNDM)
• And Permanent neonatal diabetes (PNDM)

Question 8

What are the characterisitic features of TNDM?

Answer 8

• Diabetes usually diagnosed < 1 week old (requires insulin)
• Resolves roughly 12 weeks
• Stop insulin once resolved as no longer needs it

Question 9

What are the characteristic features of PNDM?

Answer 9

• Diabetes usually diagnosed 0-6 weeks
• Require lifelong insulin treatment

Question 10

What can some neonatal diabetes be caused by ?

Answer 10

K_ATP channel mutations

Question 11

In neonatal diabetes caused by K_ATP channel mutations what can be done about there treatment ?

Answer 11

They can be taken off insulin and given a sulphonylurea

Question 12

What is MODY often misdiagnosed as ?

Answer 12

T1DM or T2DM

Question 13

What are some of the specific K_ATP mutations ?

Answer 13

Mutations in SUR1 or Kir 6.2 in the K_ATP channel