Genetic and Clinical Predictors of Age of ESKD in Individuals With Autosomal Dominant Tubulointerstitial Kidney Disease Due to UMOD Mutations

INTRODUCTION

Autosomal dominant tubulo-interstitial kidney disease due to UMOD mutations (ADTKD-UMOD) is a rare condition associated with high variability in the age of end-stage kidney disease (ESKD). The minor allele of rs4293393, located in the promoter of the UMOD gene, is present in 19% of the population and downregulates uromodulin production by approximately 50% and might affect the age of ESKD. The goal of this study was to better understand the genetic and clinical characteristics of ADTKD-UMOD and to perform a Mendelian randomization study to determine if the minor allele of rs4293393 was associated with better kidney survival.

METHODS

An international group of collaborators collected clinical and genetic data on 722 affected individuals from 249 families with 125 mutations, including 28 new mutations. The median age of ESKD was 47 years. Men were at a much higher risk of progression to ESKD (hazard ratio 1.78, P < 0.001).

RESULTS

The allele frequency of the minor rs4293393 allele was only 11.6% versus the 19% expected (P < 0.01), resulting in Hardy-Weinberg disequilibrium and precluding a Mendelian randomization experiment. An in vitro score reflecting the severity of the trafficking defect of uromodulin mutants was found to be a promising predictor of the age of ESKD.

CONCLUSION

We report the clinical characteristics associated with 125 UMOD mutations. Male gender and a new in vitro score predict age of ESKD.

Primary placement of a voice prosthesis on transposed colon after total pharyngolaryngoesophagectomy

BACKGROUND

Primary placement of a voice prosthesis may aid rehabilitation after total laryngectomy.

METHODS

We present a rare clinical situation of a T4 NO MO squamous cell carcinoma of the hypopharynx and esophagus in a patient who had previously undergone a transmesocolic Billroth II gastrectomy.

RESULTS

The patient benefited from a total pharyngolaryngoesophagectomy, with reconstruction using a transverse-descending colon transposition, and primary placement of a low-pressure voice prosthesis.

CONCLUSION

Primary placement of a voice prosthesis may be successful even in a patient who requires extensive pharyngoesophageal reconstruction using transposed colon. To our knowledge, there has been no previous report of primary placement of a voice prosthesis on a colon autograft.