Neonatal and late-onset diabetes mellitus caused by failure of pancreatic development: report of 4 more cases and a review of the literature.
OBJECTIVE
Permanent neonatal diabetes mellitus caused by developmental failure of the pancreas is rare. Thus far, only a few genetic causes have been reported. We now report the clinical and genetic aspects of 4 more cases of permanent neonatal diabetes mellitus caused by pancreatic agenesis or hypoplasia.


METHODS
All 4 of the patients were from consanguineous kinships, and all presented with diabetes mellitus and pancreatic exocrine insufficiency. Three patients had pancreatic agenesis, and 1 had pancreatic hypoplasia on computed tomography scan. DNA was extracted from blood samples of patients and unaffected family members. Specific genes were amplified by polymerase chain reaction and characterized by DNA sequencing.


RESULTS
Several genes that encode transcription factors that have known roles in pancreas development were characterized in the affected children and unaffected family members. These genes include Pdx1, the master regulator of pancreas development and beta-cell differentiation, and other transcription factors that are expressed early in pancreas development, namely, Ptf1a, Sox9, Sox17, Hnf6, and HlxB9. Several novel polymorphisms were found in our patients. However, these were also present in unaffected individuals. No disease-causing mutations were found in any of these genes.


CONCLUSIONS
These findings add to the 4 cases already in the literature in which the Pdx1 structural gene has been found to be normal in patients with pancreatic agenesis or hypoplasia. The analysis here has been extended to include the screening of 4 other candidate genes in addition to promoter elements upstream of the Pdx1. Two of the cases occurred in a sibling pair, and 2 were isolated, so there may be more than 1 etiology in the cases reported here.
King's College London, Hodgkin Building, Guy's Campus, London SE1 9UL, United Kingdom. phil.marsh@kcl.ac.uk
Rongrong
R
Chen
Khalid
K
Hussain
Maryam
M
Al-Ali
Mehul T
MT
Dattani
Peter
P
Hindmarsh
Peter M
PM
Jones
Phil
P
Marsh
D003920:Diabetes Mellitus / Q000209:etiology*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D010179:Pancreas / Q000002:abnormalities*