Kathryn R. Spears , Francis Rossignol , Monique B. Perry , Michael A. Kayser , Pim Suwannarat , Kevin E. O'Brien , Joy C. Bryant , Wendy F. Greenwood , Steve Fuller , William A. Gahl , Wendy J. Introne
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引用次数: 0
Abstract
Alkaptonuria is a rare disorder of tyrosine catabolism caused by deficiency of homogentisate 1,2-dioxygenase that leads to accumulation of homogentisic acid (HGA). Deposition of HGA-derived polymers in connective tissue causes progressive arthropathy of the spine and large joints, cardiac valvular disease, and genitourinary stones beginning in the fourth decade of life. Nitisinone, a potent inhibitor of the upstream enzyme, 4-hydroxyphenylpyruvate dioxygenase, dramatically reduces HGA production. As such, nitisinone is a proposed treatment for alkaptonuria. A randomized clinical trial of nitisinone in alkaptonuria confirmed the biochemical efficacy and tolerability of nitisinone for patients with alkaptonuria but the selected primary outcome did not demonstrate significant clinical benefit. Given that alkaptonuria is a rare disease with slow progression and variable presentation, identifying outcome parameters that can detect significant change during a time-limited clinical trial is challenging. To gain insight into patient-perceived improvements in quality of life and corresponding changes in physical function associated with nitisinone use, we conducted a post-hoc per protocol analysis of patient-reported outcomes and a functional assessment. Analysis revealed that nitisinone-treated patients showed significant improvements in complementary domains of the 36-Item Short-Form Survey (SF-36) and 6-min walk test (6MWT). Together, these findings suggest that nitisinone improves both quality of life and function of patients with alkaptonuria. The observed trends support nitisinone as a therapy for alkaptonuria.
期刊介绍:
Molecular Genetics and Metabolism contributes to the understanding of the metabolic and molecular basis of disease. This peer reviewed journal publishes articles describing investigations that use the tools of biochemical genetics and molecular genetics for studies of normal and disease states in humans and animal models.