Meet the Maker: MODY

Labcorp’s new Meet the Maker Q&A series provides insights and explores frequently asked questions on assay developments with Labcorp’s industry leading scientists. Toni Prezant is the lead scientist behind the development of Maturity-Onset Diabetes of the Young (MODY) genetic testing at Labcorp. In the first installment of Meet the Maker, Dr Prezant discusses MODY’s clinical significance and what its results mean for patients.

Introducing Dr Toni R Prezant, lead scientist behind the development of Maturity-Onset Diabetes of the Young (MODY) genetic testing at Labcorp. 

Toni R Prezant, PhD, FACMG

Clinical Laboratory Director, Labcorp

Dr Prezant is board certified in clinical molecular genetics by the American Board of Medical Genetics and Genomics and is licensed in California and certified in New York State as a laboratory director. She earned her PhD in biology from the Massachusetts Institute of Technology. Dr Prezant has more than 18 years of clinical experience in molecular genetic testing and an extensive research background, including studies of mitochondrial DNA diseases and pituitary tumorigenesis. She is a member of the American College of Medical Genetics and Genomics, the American Society of Human Genetics and the Association for Molecular Pathology.

Why was it important to add MODY to Labcorp’s test offerings?

Recent studies indicate that most cases of MODY—as many as 95%—are misdiagnosed as type 1 or type 2 diabetes.1 MODY testing can help clinicians identify patients for appropriate treatment. A diagnosis of MODY can also help identify other affected family members earlier and help predict the prognosis of the disease. Another benefit is that it can explain symptoms other than hyperglycemia and can help physicians monitor the patient for associated complications, such as renal disease.2

What were the highlights of the test development?

The MODY Genetic Profile test was developed through a coordinated team effort, including members of the lab, operations, and our scientific team. Personally, I enjoyed the challenge of applying both scientific skills and craftsmanship to create this highly complex test. Throughout the months of experimentation, I benefitted from the support of all the team members who provided valuable insight, encouragement, and growing enthusiasm to make this test available to physicians and their patients. Later, we moved the testing to our next generation sequencing platform and also added an expanded MODY panel.

Which patients may benefit from MODY testing?

The American Diabetes Association Guidelines recommend MODY screening for patients with atypical diabetes.2 Patients with MODY can present with several different clinical features, and it is becoming more difficult to differentiate between forms of diabetes.2,3 It is important to look at the overall clinical picture, including BMI and age, but also consider patient characteristics, family history, and lab results such as autoantibodies, c-peptide, and HbA1c.2,3

A patient who is diagnosed with type 1 diabetes but tests negative for diabetes autoantibodies may be considered for MODY testing. A patient who is diagnosed with type 2 diabetes but is at a healthy weight and physically active would be another possible MODY candidate.2

How can physicians use the MODY test to optimize care for their patients?

This test information can help provide additional insight into treatment plans for patients diagnosed with MODY. Treatment plans are not always the same for each form of MODY, and they certainly vary from type 1 and type 2 diabetes management.2 Depending on the form of MODY, patients may be able to switch from potentially painful and expensive insulin injections to an oral medication, which is typically less expensive and may be a more appealing option to some patients.1

Which genes are evaluated?

Our MODY 4-Gene Panel detects pathogenic variants and copy number variants in the coding sequence and exon-intron junctions of the four genes most commonly involved in MODY: HNF1A, GCK, HNF4A, and HNF1B.2 Our MODY Expanded Genetic Panel analyzes 14 genes including: ABCC8, APPL1, BLK, CEL, GCK, HNF1A, HNF1B, HNF4A, INS, KCNJ11, KLF11, NEUROD1, PAX4, PDX1.


  1. Kleinberger JW, Pollin TI. Undiagnosed MODY: Time for action. Curr Diabetes Rep. 2015;15(12):110. doi:10.1007/s11892-015-0681-7
  2. American Diabetes Association. 2. Classification and Diagnosis of Diabetes: Standards of Medical Care in Diabetes—2019. Diabetes Care. 2019;42(Supplement 1):S13-S28. doi:10.2337/dc19-S002
  3. Chiang JL, Maahs DM, Garvey KC, et al. Type 1 diabetes in children and adolescents: A position statement by the American Diabetes Association. Diabetes Care. 2018;41(9):2026-2044. doi:10.2337/dci18-0023