Genotype-phenotype correlation in 9 patients with tropical pancreatitis and identified gene mutations

The etiopathogenesis of tropical chronic pancreatitis (TCP) remains unclear. Malnutrition, dietary toxins like cyanogens in cassava and micronutrient deficiency are proposed factors. The description and characterization of genetic factors in TCP has added a new dimension to the understanding of pathogenesis of the disease. However, there is sparse data on the association of TCP with cystic fibrosis transmembrane conductance regulator (CFTR) gene mutations. We report 8 patients of TCP with CFTR gene mutations, including one with a novel mutation, and describe the clinical profile of these patients. Further prospective genetic studies on the association of CFTR gene mutations are essential in order to unravel the genetic basis of TCP.

Membranoproliferative glomerulonephritis with essential cryoglobulinemia

Cryoglobulinemia is an uncommon cause of renal disease and often occurs in patients with hepatitis C virus (HCV) infection. We report a case of membranoproliferative glomerulonephritis in a patient with cryoglobulinemia, which was not associated with HCV infection or any identifiable etiology.

Juvenile Behçet's disease: Highlighting neuropsychiatric manifestations and putative genetic mechanisms

Behçet's disease is a multisystem inflammatory disorder of unknown etiology. We report a 12-year-old boy who presented with features of raised intracranial tension and seizures and was found to have cerebral venous sinus thrombosis on evaluation. Behçet's disease was diagnosed based on occurrence of recurrent oral and genital ulcers in the past and characteristic skin lesions subsequently. He also showed significant personality changes including multiple attempts of deliberate self-harm. Pedigree analysis revealed that six family members spanning three generations had recurrent oral ulcers and three members satisfied the criteria for Behçet's disease. Clinical features varied amongst the family members and there was suggestion of genetic anticipation. The index case was carrying HLA-B37/B7 and the mother was carrying B37/B40. Our report sheds light on the genetics of Behçet's disease. Unusual features were early age of onset, cerebral venous sinus thrombosis, significant personality changes and strong family history with phenotypic heterogeneity.

Selection and validation of differentially expressed genes in head and neck cancer

We applied a robust combinatorial (multi-test) approach to microarray data to identify genes consistently up- or down-regulated in head and neck squamous cell carcinoma (HNSCC). RNA was extracted from 22 paired samples of HNSCC and normal tissue from the same donors and hybridized to the Affymetrix U95A chip. Forty-two differentially expressed probe sets (representing 38 genes and one expressed sequence tag) satisfied all statistical tests of significance and were selected for further validation. Selected probe sets were validated by hierarchical clustering, multiple probe set concordance, and target-subunit agreement. In addition, real-time PCR analysis of 8 representative (randomly selected from 38) genes performed on both microarray-tested and independently obtained samples correlated well with the microarray data. The genes identified and validated by this method were in comparatively good agreement with other rigorous HNSCC microarray studies. From this study, we conclude that combinatorial analysis of microarray data is a promising technique for identifying differentially expressed genes with few false positives.

Diagnosis of mucopolysaccharidoses: how to avoid false positives and false negatives

OBJECTIVE

This paper advocates a complete procedure, which includes both quantitative and qualitative analysis of urinary GAGs in the diagnosis of MPS in a clinically suspected population.

METHODS

Urine samples from 219 clinically suspected mucopolysaccharidoses (MPS) patients and 91 controls were analysed using a combination of methods. Quantitation of isolated urinary glycosaminoglycans (GAGs) were carried out using acid alcian blue complex formation method and qualitative urinary GAG analysis by multisolvent sequential thin layer chromatography

RESULTS

Of the 219 patients analysed, 131 were confirmed to be suffering from MPS. Quantitation of urinary GAGs alone would have missed 60 low GAG excreting MPS patients and misdiagnosed 26 high GAG excreting nonMPS as MPS patients. Further qualitative analysis and enzyme estimation were needed to identify these 60 low GAG excreting MPS patients and 26 high GAG excreting non MPS patients.

CONCLUSION

These results emphasize that quantitation of urinary GAGs alone cannot diagnose MPS patients, it should be coupled with qualitative analysis and enzyme estimations for differential/definitive diagnosis.

Discontinuous electrophoresis of glycosaminoglycans: a screening method for mucopolysaccharidoses

A modified discontinuous electrophoretic method for the separation of standard and urinary glycosaminoglycans has been reported. The merits of the method are the simple and easy to handle apparatus, non-requirement of elaborate cooling system, sensitivity and high reproducibility of the results and applicability of the method for the preliminary grouping of the MPS patients to reduce the number of enzyme assays to be done.