Clinical Trial: Histamine Responsiveness in McCune-Albright Syndrome
Study Status: Recruiting
Recruit Status: Unknown status
Study Type: Observational
Official Title: Histamine Responsiveness in Patients With McCune-Albright Syndrome
Brief Summary:
McCune-Albright syndrome (MAS) is a syndrome caused by a genetic mutation that causes a specific protein in the body called a G protein to be constantly active. Children with McCune-Albright syndrome classically have early puberty, areas of increased skin pigmentation, and bone lesions resulting from the constant activity of the specific protein involved.
Histamines are known to play a role in allergies and related allergic problems. The effects of histamines are controlled by the same G protein that is overly active in McCune-Albright syndrome. Thus, one could predict that patients with McCune-Albright may be at high risk for allergic problems. To date, no studies have documented any form of histamine excess or allergic difficulties in patients with McCune-Albright syndrome. However, the investigators have made the observation that a high percentage of their patients with MAS exhibit a range of allergic symptoms, from mild symptoms, to severe, life-threatening symptoms.
The purpose of this study is to demonstrate increased histamine response by using a histamine skin test in patients with MAS. If increased reactions to histamines can be documented in MAS patients when compared to controls, severe and potentially life threatening allergic reactions in children with MAS could be anticipated and avoided.
Detailed Summary:
Objectives of this study are to determine if:
- Patients with McCune-Albright syndrome differ from unaffected controls in wheal and flare response to histamine and codeine.
- Affected skin will differ from unaffected skin in wheal and flare response to histamine and codeine.
- IgE and IL-4 levels in MAS patients differ from normal controls.
Specific Aims:
- Compare the skin response of MAS patients to normal controls using standard histamine and codeine skin testing.
- Compare skin testing response in MAS patients with known standards for skin testing. Compare response to histamine and codeine skin testing in MAS patient’s affected (café-au-lait) skin to unaffected (normal) skin.
- Compare IgE and IL-4 levels in patients with MAS to controls.
Background:
The McCune-Albright syndrome (MAS) is a genetic disorder characterized by constitutive activation of the Gαs proteins involved in the adenylyl cyclase enzyme. The disease is now known to be caused by a genetic mutation, commonly a substitution of histadine or cysteine for arginine at amino acid 201 in the Gαs protein. Adenylyl cyclase, with its formation of cyclic AMP (cAMP), works as a second messenger for many cellular and hormonal events. Clinically, MAS is characterized classically by precocious puberty, café-au-lait skin markings, and bone lesions termed polyostotic fibrous dysplasia. Other conditions that represent overactivity of receptor-coupled adenylate cyclase include hyperthyroidism res
Sponsor: Children's Mercy Hospital Kansas City
Current Primary Outcome:
Original Primary Outcome:
Current Secondary Outcome:
Original Secondary Outcome:
Information By: Children's Mercy Hospital Kansas City
Dates:
Date Received: April 24, 2006
Date Started: November 2003
Date Completion:
Last Updated: May 1, 2006
Last Verified: November 2004
