title: X-linked dominant protoporphyria: The first reported Japanese case.
abstract: A 12-year-old boy with photosensitivity since 3 years of age presented with small concavities on both cheeks, the nasal root and the dorsal surface of both hands. According to the clinical features, erythropoietic protoporphyria (EPP) was suspected. Urine and blood samples were tested for porphyrin derivatives, which revealed a markedly elevated level of erythrocyte protoporphyrin (EP) and a diagnosis of EPP was made. The patient's mother had no photosensitivity, however, lesions appearing slightly as small scars were found on the dorsum of her right hand; his elder sister and father showed no rash. The EP levels were elevated in samples from his mother and mildly elevated in those from his elder sister and father. To obtain a definitive diagnosis, genetic analyses were performed using samples from all family members, which revealed no mutations in the ferrochelatase-encoding gene (FECH), which is responsible for EPP. Instead, a pathological mutation of the 5-aminolevulinic acid synthase-encoding gene (ALAS2) was identified in samples from the patient, his mother and his elder sister, confirming a definitive diagnosis of X-linked dominant protoporphyria (XLDPP). This is the first Japanese family reported to have XLDPP, demonstrating evidence of the condition in Japan. In addition, because XLDPP is very similar to EPP in its clinical aspects and laboratory findings, a genetic analysis is required for the differential diagnosis.
authors.affiliation: Department of Dermatology, Osaka Medical College, Osaka, Japan.
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Ninomiya
authors.affiliation: Department of Dermatology, Osaka Medical College, Osaka, Japan.
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Kokunai
authors.affiliation: Department of Dermatology, Osaka Medical College, Osaka, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Tanizaki
authors.affiliation: Department of Dermatology, Hirosaki University Graduate School of Medicine, Aomori, Japan.
authors.forename: Eijiro
authors.initials: E
authors.lastname: Akasaka
authors.affiliation: Department of Dermatology, Hirosaki University Graduate School of Medicine, Aomori, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Nakano
authors.affiliation: Department of Dermatology, Osaka Medical College, Osaka, Japan.
authors.forename: Shinichi
authors.initials: S
authors.lastname: Moriwaki
mesh_terms: D000624:5-Aminolevulinate Synthetase / Q000032:analysis / Q000172:deficiency* / Q000235:genetics; D000483:Alleles; D002610:Cheek; D002648:Child; D003937:Diagnosis, Differential; D005294:Ferrochelatase / Q000235:genetics*; D040181:Genetic Diseases, X-Linked / Q000175:diagnosis* / Q000235:genetics*; D006225:Hand; D006801:Humans; D007564:Japan; D008297:Male; D009154:Mutation; D010375:Pedigree; D046351:Protoporphyria, Erythropoietic / Q000175:diagnosis* / Q000235:genetics*; D011524:Protoporphyrins / Q000032:analysis*
chemical_list: D011524:Protoporphyrins; C028025:protoporphyrin IX; D000624:5-Aminolevulinate Synthetase; C480079:ALAS2 protein, human; D005294:Ferrochelatase
keywords: 5-aminolevulinic acid synthase 2; X-linked dominant protoporphyria; erythropoietic protoporphyria; ferrochelatase; genetic analysis; lyonization