Male Subjects Affected By Hypohidrotic Ectodermal Dysplasia: Intrafamilial Variation

This study in affected Hypohidrotic Ectodermal Dysplasia (HED) males and unaffected male controls, age 1 year and up, will use minimally invasive devices to image sweat ducts in intact skin, to measure stimulated sweat rate, and in a subset of subjects to collect clipped scalp hair samples for RNA analysis. This study is descriptive in nature and is intended to assess the ability to use innovative approaches to generate data from subjects over a wide age spectrum, with particular emphasis on phenotype variability between male siblings (same mutation).

This pilot study in affected HED males and unaffected male controls, age 1 year and up, will use minimally invasive devices to image sweat ducts in intact skin, to measure stimulated sweat rate, and in a subset of subjects to collect clipped scalp hair samples for RNA analysis. This study is descriptive in nature and is intended to assess the ability to use innovative approaches to generate data from subjects over a wide age spectrum, with particular emphasis on phenotype variability between male siblings (same mutation). To this end, priority will be given to families that contain multiple affected siblings (i.e. two brothers). Summary data will be generated for the various groups tested, but no power calculations are involved.

Eligibility Criteria:
Inclusion Criteria:

* Registered and attending the 2011 NFED Family Conference;
* One year of age or greater;
* Conform to one of the following requirements for providing informed consent/assent:

  * if more than 18 years of age, subjects must provide signed informed consent;
  * if less than 18 years of age and it is determined that the subject is capable of providing assent, both the assent of the subject and consent of the parent(s) or guardian of that subject must be granted. Under this condition, both parents of the subject should give their permission, unless 1 parent is deceased, unknown, incompetent, or not available;
  * if the subject is incapable of providing assent, the consent of the parent(s) or guardian of the subject must be granted. Under this condition, both parents should give their consent, unless 1 parent is deceased, unknown, incompetent, or not available.
* As described in Section 3.2 above, subjects must meet one of the following criteria:

  * Male subjects with the clinical characteristics of HED, including at least a history of decreased sweating and either abnormal teeth (fewer permanent teeth, teeth are smaller than average and often have conical crowns), and/or sparseness of scalp and body hair (Male HED subjects with an affected sibling also enrolling in the study will be given priority to be in the study);
  * Healthy male controls, i.e. either unaffected male family members or unaffected male volunteers.

Exclusion Criteria:

* Known hypersensitivity to pilocarpine or pilocarpine-like muscarinic agonists;
* Known hypersensitivity to lidocaine or lidocaine like agents;
* Presence of pacemakers;
* Subjects who are not able or are not willing to comply with the procedures of this protocol;
* Subjects with any major medical problem that will prevent them from participating in this study.