MODY vs Type 2 diabetes and LADA
How to tell MODY and Type 2 diabetes and LADA apart when a board question makes them look alike.
MODY is autosomal dominant young nonobese antibody-negative beta-cell dysfunction; type 2 is resistance; LADA is adult autoimmune diabetes.
Side by side
Maturity-onset diabetes of the young causes early nonketotic hyperglycemia in a nonobese patient with autosomal dominant family history and negative autoantibodies.
Type 2 diabetes centers on insulin resistance; latent autoimmune diabetes in adults is adult-onset autoimmune beta-cell loss with positive antibodies and progressive insulin need.
Monogenic beta-cell dysfunction impairs glucose-stimulated insulin secretion without autoimmune destruction or primary insulin resistance.
Type 2 begins with insulin resistance; LADA is slower autoimmune beta-cell destruction presenting in adulthood.
Early-onset diabetes across successive generations, negative antibodies, preserved C-peptide, and nonobese phenotype support MODY.
Obesity/acanthosis with high insulin supports type 2; anti-GAD or other islet antibodies in an adult support LADA.
The trap
Age and weight alone do not classify diabetes. The deciding tests are antibodies, C-peptide, family history, and ketosis tendency. MODY (Maturity-Onset Diabetes of the Young) is autosomal dominant beta-cell dysfunction in a young nonobese patient with a 3-generation family history of diabetes, antibody-NEGATIVE, preserved C-peptide, no ketosis tendency (HNF1A and glucokinase mutations are the high-yield types; HNF1A-MODY responds dramatically to low-dose sulfonylureas, often not insulin). Type 2 diabetes is insulin resistance plus relative beta-cell failure in obese adults with metabolic syndrome (high triglycerides, low HDL, hypertension, acanthosis nigricans), antibody-NEGATIVE, normal or high C-peptide. LADA (Latent Autoimmune Diabetes of Adults) is slow-onset adult type 1 diabetes, antibody-POSITIVE (GAD-65, IA-2), low C-peptide that declines over years; usually presents as 'failure of oral agents' in a thin adult initially diagnosed as type 2 early insulin is appropriate.
The repair move
For atypical diabetes, ask inheritance, antibodies, C-peptide, obesity/resistance, and ketosis tendency.
Try a free question
CoreA nonobese 17-year-old has mild fasting hyperglycemia, negative islet autoantibodies, preserved C-peptide, no ketosis, and diabetes in three successive generations. Which diagnosis is most likely?
Show answer and explanation
Answer: A. MODY. Young nonobese antibody-negative diabetes with autosomal dominant family history supports MODY.
Why the other choices are tempting
- B. Type 2 diabetes is more strongly tied to insulin resistance and obesity/acanthosis clues.
- C. LADA is adult-onset autoimmune diabetes with islet autoantibodies.
- D. Type 1 diabetes usually has autoantibodies, low C-peptide, and ketosis tendency.
- E. Cushing syndrome causes cortisol-excess features along with hyperglycemia.
Flashcards
Tap a card to flip it.
What inheritance pattern points to MODY?
Autosomal dominant diabetes across generations points to MODY.
What antibody pattern points away from MODY?
Positive islet autoantibodies point toward autoimmune diabetes such as type 1 diabetes or LADA.
Quick answers
What is the fastest way to tell MODY from Type 2 diabetes and LADA?
MODY is autosomal dominant young nonobese antibody-negative beta-cell dysfunction; type 2 is resistance; LADA is adult autoimmune diabetes.
What is the key clue for MODY?
Maturity-onset diabetes of the young causes early nonketotic hyperglycemia in a nonobese patient with autosomal dominant family history and negative autoantibodies.
What is the key clue for Type 2 diabetes and LADA?
Type 2 diabetes centers on insulin resistance; latent autoimmune diabetes in adults is adult-onset autoimmune beta-cell loss with positive antibodies and progressive insulin need.
What is the common trap with MODY vs Type 2 diabetes and LADA?
Age and weight alone do not classify diabetes. The deciding tests are antibodies, C-peptide, family history, and ketosis tendency. MODY (Maturity-Onset Diabetes of the Young) is autosomal dominant beta-cell dysfunction in a young nonobese patient with a 3-generation family history of diabetes, antibody-NEGATIVE, preserved C-peptide, no ketosis tendency (HNF1A and glucokinase mutations are the high-yield types; HNF1A-MODY responds dramatically to low-dose sulfonylureas, often not insulin). Type 2 diabetes is insulin resistance plus relative beta-cell failure in obese adults with metabolic syndrome (high triglycerides, low HDL, hypertension, acanthosis nigricans), antibody-NEGATIVE, normal or high C-peptide. LADA (Latent Autoimmune Diabetes of Adults) is slow-onset adult type 1 diabetes, antibody-POSITIVE (GAD-65, IA-2), low C-peptide that declines over years; usually presents as 'failure of oral agents' in a thin adult initially diagnosed as type 2 early insulin is appropriate.