A fetus is found to have absence of the dorsal pancreatic bud derivatives. Which transcription factor mutation is most likely responsible?

• A PDX1 (pancreatic and duodenal homeobox 1)
• B PTF1A ✓
• C FOXA2 (HNF3-beta)
• D NGN3 (Neurogenin 3)

Explanation

PTF1A (Pancreas Transcription Factor 1A) is specifically required for the development of the dorsal pancreatic bud; mutations result in pancreatic agenesis or hypoplasia of the dorsal pancreas including the body and tail, leading to neonatal diabetes. PDX1 is required for both buds and its loss causes complete pancreatic agenesis. FOXA2 is a broader endodermal transcription factor. NGN3 is required for endocrine cell specification (islet differentiation) rather than bud formation. This distinction between dorsal-specific (PTF1A) and both-bud (PDX1) is clinically testable.

Reference: BD Chaurasia's Human Anatomy, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.