Severe Acne in Female-to-Male Transgender Patients.

and grains, hyperkeratosis, and parakeratosis. Both present clinically with hyperkeratotic papules andwarty plaques but differ in their ageofonset andassociatedabnormalities.ADEN is often congenital, while DD typically manifests in the second or third decade of life. Typically, DD has associated nail abnormalities, mucous membrane involvement, palmoplantar pits, and punctate keratoses, while ADEN does not.2 Genetic testing is available, as is immunohistochemical staining of tissue for SERCA2 protein expression. The genetic difference between the 2 disorders remains controversial. Darier disease is caused by mutations in ATP2A2, which encodes the SERCA2pump.MutationsofSERCA2havebeendiscovered in at least 2 patients with ADEN, leading some clinicians to classify ADEN as segmental DD resulting from postzygotic mosaicism.3 Others maintain that congenital or earlychildhoodonsetand lineardistributionsuggestADENand notsegmentalDD.4There is 1 reportedcaseofADENwhere lack of ATP2A2mutation was confirmed by DNA analysis.5 In our patient, IHC staining identified SERCA2 protein in lesional skin. However, the IHC staining does not substantiatenormal functionof theprotein.Genetic testingwasnoteconomically feasible for this familybutmaybeappropriatewhen apatientdesiresgeneticcounseling,prenataldiagnosis,or identificationof at-risk familymembers. TheGenetic TestingRegistry lists several laboratories thatwillperformsequenceanalysis of the ATP2A2 gene.6 With 96% specificity, the lack of ATP2A2 genemutationnearly excludes adiagnosis ofDD.Our case supports the premise that ADEN has clinical and prognostic features distinct fromDDdespite their overlappinghistopathologic findings. Although IHC staining of SERCA2 can be helpful, further study of genotype-phenotype correlations may allow better distinction of these 2 clinical entities.