Maturity-Onset Diabetes of the Young

What does Maturity-Onset Diabetes of the Young (MODY) look like?

Determining which type of diabetes a patient has is critical in providing the proper care and treatment. However, a rise in childhood obesity has made distinguishing between type 1 and type 2 diabetes increasingly more challenging.4 Additionally, MODY is often misdiagnosed as Type 1 or Type 2 diabetes due to the similarities in clinical presentation.5 In fact, up to 95% of MODY diabetes cases are misdiagnosed, and these patients may receive inappropriate treatment.2,5

According to the American Diabetes Association, physicians should consider testing patients who were diagnosed in youth or early adulthood and have a strong family history of diabetes. Additionally, patients who were diagnosed with diabetes in youth or early adulthood, but do not present with typical features of Type 1 or Type 2 diabetes, may also benefit from testing. Patients with atypical characteristics may3:

  • Be diagnosed with Type 1 diabetes, but test negative for diabetes-associated autoantibodies
  • Be diagnosed with Type 2 diabetes, but are not obese and/or do not have a sedentary lifestyle
  • Have stable, mild fasting hyperglycemia at diagnosis
  • Have stable HbA1c between 5.6 and 7.6% at diagnosis

Most people diagnosed with MODY have impaired insulin secretion and typically experience onset before they are 25 years old.3 The four most common forms of MODY are caused by mutations in HNF1A (MODY3), GCK (MODY2), HNF4A (MODY1), and HNF1B (MODY5).3,6

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 most patients.2 In addition to optimizing treatment, correctly diagnosing MODY can assist in diagnosing other affected family members and predicting the prognosis of the disease.3 A specific MODY diagnosis can also explain symptoms other than diabetes and allow for increased surveillance of associated complications.3 

Meet the Maker

Learn more about the development of our MODY assay in our new Meet the Maker Q&A series.

 

Up to 95% of MODY diabetes cases are misdiagnosed.

 

Maturity-Onset Diabetes of the Young (MODY) Genetic Profile

Test #: 504603
CPT: 81404; 81405(x2); 81406(x2)

Use

Maturity-onset diabetes of the young (MODY) is a suspected diagnosis in young non-obese patients who lack an autoimmune cause for diabetes and who have a family history of diabetes in successive generations. The majority of MODY cases are due to mutations in one of four genes. Identifying a mutation in one of these MODY genes can lead to improved treatment, increased surveillance for related symptoms, and earlier detection in currently asymptomatic family members. GCK encodes the enzyme glucokinase, a key regulator of glucose metabolism in pancreatic beta cells. The three HNF (hepatic nuclear factor) genes encode transcription factors that regulate gene expression in the pancreas.

Mody #

Gene

Chromosome Location

RefSeq (Gene)

Transcript

MODY 3

HNF1A

12q24.31

NG_011731.2

NM_000545.6

MODY 1

HNF4A

20q13.12

NG_009818.1

NM_175914.4

MODY 5

HNF1B

17q12

NG_013019.2

NM_000458.3

MODY 2

GCK

7p13

NG_008847.2

NM_000162.5

Methodology

Sanger sequencing and MLPA

Full Test Details