Monogenic diabetes (MODY)

• MODY is an abbreviation of Maturity Onset Diabetes of the Young and includes a group of genetic disorders where something is wrong with the way in which the patient manages insulin, leading to diabetes. 
• These conditions are strongly inherited, you only need one MODY gene (instead of a gene pair) to show signs of the condition, in an inheritance pattern called autosomal dominance. 
• If you have MODY you have a 50% chance of passing it on to each of your children.

Why do midwives need to know about?

• Several of the different MODY types are associated with problems in pregnancy. 
• Each subtype does something a bit different, so there is more information about each type below

What do midwives need to do about it?

• Be aware these conditions exist
• At booking, if the expectant mother or father has diabetes in the family ask what type it is. 
• If they tell you they (either parent) have MODY in the family, ask which type, and refer all patients to you local diabetes ANC for review within the next couple of weeks
• Depending on which MODY type, the mother and baby may need extra growth scans, a planned NICU bed or blood glucose monitoring.
• The families need special MODY tests in pregnancy where maternal blood can be taken to screen for baby genotype to work out risks.  The Diabetes team will help work out if this is needed

Family testing for MODY patients (cascade testing)

As all forms of MODY are inherited in an autosomal dominant manner, family members of your patient who has diabetes may also have MODY.

Who needs to be tested?

• Any blood-related family member with Diabetes Mellitus
• Other family members can have HbA1c testing as a screening test before going on to get genetic testing
• Children are usually not tested until they are old enough to understand the testing (generally after 16  years of age).  Most forms of MODY do not manifest issues for children, with patients only developing glucose-handling problems in adolescence or adulthood. Neonatal diabetes, although autosomal dominant, is often a de novo mutation

Available to download from our Infographics page.

General information on MODY:   

MODY: https://www.diabetesgenes.org/what-is-mody/ 

Neonatal diabetes: https://www.diabetesgenes.org/about-neonatal-diabetes/ 

Course on genomics and monogenic diabetes: https://www.futurelearn.com/courses/diabetes-genomic-medicine 

On our website via general monogenic diabetes talks (3 videos found under ‘additional training’): https://www.diabetesgenes.org/training/ 
 

When to consider genetic testing:

Guidelines for genetic testing in MODY: https://www.diabetesgenes.org/tests-for-diabetes-subtypes/guidelines-for-genetic-testing-in-mody/

MODY calculator app: https://www.diabetesgenes.org/exeter-diabetes-app/

What do you need to do:

Genetic Test Referral Form: https://www.diabetesgenes.org/genetic-test-referral-forms/

Details on c-peptide and autoantibody testing: https://www.diabetesgenes.org/nongenetictests/

Various tests for diabetes subtypes: https://www.diabetesgenes.org/tests-for-diabetes-subtypes/

Resources for clinicians:

Self-paced online training course and 2 day training course: https://www.diabetesgenes.org/training/ 

Ongoing support through GMSA diabetes consultant and GDNs leads to extend / further develop skills (and access to Masterclasses once they are developed). https://www.diabetesgenes.org/training/genetic-diabetes-nurses/

Resources of patients:

https://www.diabetesgenes.org/tests-for-diabetes-subtypes/information-for-people-with-diabetes/

https://www.diabetesgenes.org/tests-for-diabetes-subtypes/information-for-family-members/