Nitisinone for Type 1B Oculocutaneous Albinism

Summary

Background: \- Oculocutaneous albinism, type 1B (OCA1B) is a genetic disease caused by problems in the gene that makes tyrosine. Tyrosine is an amino acid needed to produce pigment in the skin, hair, and eyes. People with OCA1B have pale skin, white hair, and light-colored eyes. Pigment in the back of the eye helps vision, so people with OCA-1B often have visual problems. Researchers want to see if a drug called nitisinone can help improve eye pigmentation and vision in people with OCA1B. Nitisinone is approved for treating a related genetic disease that causes problems with tyrosine, so it may help people with OCA1B. Objectives: \- To see if nitisinone can help improve eye pigmentation and vision in people with OCA1B. Eligibility: \- Individuals at least 18 years of age who have OCA1B. Design: * This study will last about 18 months. It requires eight outpatient visits, each about 3 months apart. Each visit will require 1 to 2 days of testing. * Participants will be screened with a physical exam, eye exam, and medical history. They will have additional vision and neurological tests. They will be tested to see how their brain and retinas respond to light. They will also take hair and blood samples, and answer questions about diet. * Participants will receive the study drug. They will take one pill a day for 1 year. They will keep track of the dose in a study diary. * At the outpatient visits, participants will have the following tests: * Medical history and physical exam * Neurological and eye exams * Retina function tests * Tests of the skin and brain's response to light * Blood and urine tests * Dietary consultation * Visual function questionnaire. * After the end of the study, participants will return to the care of their regular eye doctor.

Timeline

Start

2013-04-16

Primary completion

2016-07-11

Completion

2017-02-07

Publications

• Background Hertle RW, Anninger W, Yang D, Shatnawi R, Hill VM. Effects of extraocular muscle surgery on 15 patients with oculo-cutaneous albinism (OCA) and infantile nystagmus syndrome (INS). Am J Ophthalmol. 2004 Dec;138(6):978-87. doi: 10.1016/j.ajo.2004.07.029.
• Background Giebel LB, Tripathi RK, King RA, Spritz RA. A tyrosinase gene missense mutation in temperature-sensitive type I oculocutaneous albinism. A human homologue to the Siamese cat and the Himalayan mouse. J Clin Invest. 1991 Mar;87(3):1119-22. doi: 10.1172/JCI115075.
• Background Giebel LB, Tripathi RK, Strunk KM, Hanifin JM, Jackson CE, King RA, Spritz RA. Tyrosinase gene mutations associated with type IB ("yellow") oculocutaneous albinism. Am J Hum Genet. 1991 Jun;48(6):1159-67.
• Results Adams DR, Menezes S, Jauregui R, Valivullah ZM, Power B, Abraham M, Jeffrey BG, Garced A, Alur RP, Cunningham D, Wiggs E, Merideth MA, Chiang PW, Bernstein S, Ito S, Wakamatsu K, Jack RM, Introne WJ, Gahl WA, Brooks BP. One-year pilot study on the effects of nitisinone on melanin in patients with OCA-1B. JCI Insight. 2019 Jan 24;4(2):e124387. doi: 10.1172/jci.insight.124387.

Drugs

Indications