Molecular analysis of uromodulin and SAH genes, positional candidates for autosomal dominant medullary cystic kidney disease linked to 16p12

Background. The location of a second genetic locus for autosomal dominant medullary cystic kidney disease (ADMCKD) at chromosome 16p12 led us to further investigate the molecular analysis of the critical region where two genes coding for uromodulin and SA proteins with renal specific functions, UMOD and SAH, are localized. Methods: We characterized the intron-exon boundary sequences by screening phage and BAC DNA genomic clones for the development of new molecular tools functional to the mutation analysis of UMOD and SAH genes. Results: No consistent mutations for ADMCKD2 were found in the UMOD and SAH genes. We identified a silent polymorphism in the UMOD gene at codon C174 which co-segregates with the disease in the ADMCKD2 family. Conclusions: This study excludes the involvement of uromodulin and SAH genes in ADMCKD2, and provides new tools for their molecular analysis in other diseases.