title: Allergic manifestations and cutaneous histamine responses in patients with McCune Albright syndrome.
abstract: BACKGROUND
  McCune Albright syndrome (MAS) is a rare disorder characterized by precocious puberty, café-au-lait spots, and fibrous dysplasia. Its cause is an activating mutation in the GNAS gene, encoding a subunit of the stimulatory G protein, Gsalpha (Gsα). The action of any mediator that signals via Gsα and cyclic AMP can be up regulated in MAS. We had observed gastritis, gastroesophageal reflux, and anaphylaxis in McCune Albright patients.
  
  
  OBJECTIVE
  As histamine is known to signal via histamine 1 (H1) and histamine 2 (H2) receptors, which couple with stimulatory G proteins, we attempted to mechanistically link histamine responsiveness to the activating GNAS mutation. We hypothesized that responsiveness to histamine skin testing would differ between MAS patients and healthy controls.
  
  
  METHODS
  After obtaining informed consent, we performed a systematic review of histamine responsiveness and allergic manifestations in 11 MAS patients and 11 sex-matched, Tanner-stage matched controls. We performed skin prick testing, quantifying the orthogonal diameters of wheals and erythema. We also quantitated G protein mRNA expression.
  
  
  RESULTS
  The peak wheal and flare responses to histamine were significantly higher in MAS patients compared to controls.
  
  
  CONCLUSIONS
  This study suggests that MAS patients may be at risk for exaggerated histamine responsiveness compared to unaffected controls.
authors.affiliation: Section of Endocrinology, Children's Mercy Hospital, University of Missouri-Kansas City, School of Medicine, 2401 Gillham Road, Kansas, MO 64108, USA. jjacobson@cmh.edu.
authors.forename: Jill D
authors.initials: JD
authors.lastname: Jacobson
authors.forename: Angela L
authors.initials: AL
authors.lastname: Turpin
authors.forename: Scott A
authors.initials: SA
authors.lastname: Sands