Study of Dietary N-3 Fatty Acids in Patients With Retinitis Pigmentosa and Usher Syndrome

Overview

OBJECTIVES: I. Examine the concentration of docosahexanoic acid (DHA) and other n-3 fatty acids in plasma, erythrocyte, and adipose tissue in patients with various forms of retinitis pigmentosa and Usher syndrome. II. Determine the synthesis and catabolism of DHA from linolenic acid in these patients. III. Determine the synthesis, absorption, and catabolism of DHA under different dietary conditions in these patients.

Study Type

  • Study Type: Observational

Detailed Description

PROTOCOL OUTLINE: Patients may participate in one or more of the arms of this study. Arm I (adipose tissue study): Adipose tissue is collected from the buttocks of patients with Usher II retinitis pigmentosa (RP), patients with non-Usher RP, and control subjects. Dietary histories are obtained from all patients and subjects. Arm II (isotope study): Patients meeting the same criteria as in arm I receive oral D5-labeled linolenic acid and oral D4-labeled linolenic acid that is dissolved in oil and incorporated into foods. Subjects must avoid eating fish and shellfish during the 35 days of the isotope study. Blood samples are collected at 0, 8, 24, and 48 hours, daily on days 3-7, and then on days 10, 18, and 35. Arm III (flaxseed oil feeding): Patients with all types of RP and control subjects receive flaxseed oil, a form of linolenic acid, for 12 weeks. Subjects may also receive high oleic safflower oil or olive oil as a control fat for 12 weeks. Subjects complete a diet history at the end of each fatty acid supplementation period. All subjects must follow a diet free of seafood and fish oil supplements.

Participating in This Clinical Trial

PROTOCOL ENTRY CRITERIA:

  • Retinitis pigmentosa, including: Usher syndrome (types I and II) Simplex – The following inheritance patterns eligible: X-linked recessive; Autosomal dominant; Autosomal recessive

Gender Eligibility: All

Minimum Age: 0 Years

Maximum Age: N/A

Are Healthy Volunteers Accepted: Accepts Healthy Volunteers

Investigator Details

  • Lead Sponsor
    • National Center for Research Resources (NCRR)
  • Collaborator
    • Oregon Health and Science University
  • Overall Official(s)
    • William Connor, Study Chair, Oregon Health and Science University

Clinical trials entries are delivered from the US National Institutes of Health and are not reviewed separately by this site. Please see the identifier information above for retrieving further details from the government database.

At TrialBulletin.com, we keep tabs on over 200,000 clinical trials in the US and abroad, using medical data supplied directly by the US National Institutes of Health. Please see the About and Contact page for details.