Pancreatitis in fibrocalculous pancreatic diabetes mellitus is not associated with common mutations in the trypsinogen gene

BACKGROUND

A distinct type of pancreatitis associated with diabetes, termed fibrocalculous pancreatic diabetes (FCPD), has been reported in tropical developing countries including Bangladesh. The molecular basis for autosomal dominant hereditary pancreatitis (HP) has recently been attributed to mutations in exons 2 and 3 of the trypsinogen gene. We have investigated the hypothesis that mutations in the aforementioned exons of this gene might also predispose to FCPD.

METHODS

Seventy Bangladeshi and 50 South Indian unrelated FCPD patients and seven South Indian families with FCPD probands were studied. Pancreatic calcification was confirmed by abdominal X-ray, ultrasound and/or ERCP. Established mutations of exons 2 and 3 of the trypsinogen gene were studied in these subjects by PCR-RFLP analysis and DNA sequencing.

RESULTS

The mutations found in hereditary pancreatitis were not observed in this collection of FCPD subjects, and complete DNA sequencing of exons 2 and 3 of the fourth cationic trypsinogen gene also excluded any new mutations.

CONCLUSIONS

These results indicate that chronic pancreatitis of FCPD is unlikely to be caused by common mutations in the trypsinogen gene.

Family association studies of markers on chromosome 2q and Type 1 diabetes in subjects from South India

BACKGROUND

Several Type 1 diabetes susceptibility loci have been located to chromosome 2q12-21. However, results have not always been consistent and this may reflect study design and the population analysed. We have used a family-based design to look for an association between Type 1 diabetes and markers located to 2q12-21.

METHODS

Ninety-one South Indian families consisting of subjects with Type 1 diabetes and their parents were genotyped for eight polymorphic markers localised to 2q12-21, which includes the interleukin-1 gene cluster. Radiation hybrid mapping was used to localise the map position of D2S308 and D2S363 on 2q12-21. The extended transmission disequilibrium test was used for statistical analysis.

RESULTS

No associations were found between Type 1 diabetes and markers located in and around the interleukin-1 gene cluster or the interleukin-1 Type 1 receptor. In contrast, a suggestive association was found between Type 1 diabetes and two closely-linked markers telomeric of the interleukin-1 gene cluster (D2S308 and D2S363, separated by 3.3 cR) (p=0.004 and p=0.002, respectively).

CONCLUSION

This preliminary study suggests that a locus close to D2S308 and D2S363 is involved in the aetiology of Type 1 diabetes in the South Indian population.