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Objective To determine the clinical presentation, diagnostic variables, risk factors and disease burden in children with chronic pancreatitis. Study design We performed a cross-sectional study of data from INSPPIRE (International Study Group of Pediatric Pancreatitis: In search for a cuRE), a registry of children with acute recurrent pancreatitis and chronic pancreatitis. Between-group differences were compared using Wilcoxon rank-sum test. Results Among 170 subjects in the registry, 76 (45%) had chronic pancreatitis; 57% were female, 80% were Caucasian, median age at diagnosis was 9.9 years. Pancreatitis-predisposing genetic mutations were identified in 51 (67%) and obstructive risk factors in 25 (33%). Toxic/metabolic and autoimmune factors were uncommon. Imaging demonstrated ductal abnormalities and pancreatic atrophy more commonly than calcifications. Fifty-nine (77%) reported abdominal pain within the past year; pain was reported as constant and receiving narcotics in 28%. Children with chronic pancreatitis reported a median of 3 emergency room visits and 2 hospitalizations in the last year. Forty-seven subjects (70%) missed one day of school in the past month due to chronic pancreatitis; 26 (34%) missed 3 or more days. Children reporting constant pain were more likely to miss school (p=0.002), visit emergency room (p=0.01) and experience hospitalizations (p=0.03) compared with children with episodic pain. Thirty-three children (43%) underwent therapeutic ERCP; one or more pancreatic surgeries were performed in 30 (39%). Conclusions Chronic pancreatitis occurs at a young age with distinct clinical features. Genetic and obstructive risk factors are common, and disease burden is substantial.

Mutations in the gene encoding the endothelin receptor type B (EDNRB) produce congenital aganglionic megacolon and pigment abnormalities in mice and humans. Here we report a naturally occurring null mutation of the EDNRB gene in spotting lethal (si) rats, which exhibit aganglionic megacolon associated with white coat color. We found a 301-bp deletion spanning the exon 1-intron 1 junction of the EDNRB gene in sl rats. A restriction fragment length polymorphism caused by this deletion perfectly cosegregates with the sl phenotype. The deletion leads to production of an aberrantly spliced EDNRB mRNA that lacks the coding sequence for the first and second putative transmembrane domains of the G-protein-coupled receptor. Radioligand binding assays revealed undetectable levels of functional EDNRB in tissues from homozygous sl/sl rats. We conclude that EDNRB plays an essential role in the normal development of two neural crest-derived cell lineages, epidermal melanocytes and enteric neurons, in three mammalian species-humans, mice, and rats. The EDNRB-deficient rat may also prove valuable in defining the postnatal physiologic role of this receptor.

Loss of Endothelin-3/Endothelin receptor B (EDNRB) signaling leads to aganglionosis of the distal gut (Hirschsprung's disease), but it is unclear whether it is required primarily for neural crest progenitor maintenance or migration. Ednrb-deficient gut neural crest stem cells (NCSCs) were reduced to 40% of wild-type levels by embryonic day 12.5 (E12.5), but no further depletion of NCSCs was subsequently observed. Undifferentiated NCSCs persisted in the proximal guts of Ednrb-deficient rats throughout fetal and postnatal development but exhibited migration defects after E12.5 that prevented distal gut colonization. EDNRB signaling may be required to modulate the response of neural crest progenitors to migratory cues, such as glial cell line-derived neurotrophic factor (GDNF). This migratory defect could be bypassed by transplanting wild-type NCSCs directly into the aganglionic region of the Ednrb(sl/sl) gut, where they engrafted and formed neurons as efficiently as in the wild-type gut.