UNIVERSAL DYSCHROMATOSIS - A FAMILY STUDY

Introduction. Universal dyschromatosis is a generalized leucomelanoder mia recognised in Japan in 1933. We report a family with universal dys chromatosis, demonstrating the mode of transmission. The ultrastructur al aspects are compatible with a functional melanogenesis anomaly. Cas e report. A 9-year-old girl was hospitalized for recently diagnosed in sulin-dependent diabetes mellitus. She was born to nonconsanguinous pa rents and her past medical history was uneventful. Her father was of m ixed ethnic origin. The physical examination revealed generalized leuk omelanoderma identified since the first year of life. Zones of small a chromatic maculae alternated with zones of pigmented maculae of variab le size and color. Lesions were diffuse but predominated on the trunk and did not involve the face, the hands or the feet. Neither the child nor her father who also has leukomelanoderma were photosensitive. A s kin biopsy from the gluteal region revealed alternating zones of hyper - and hypopigmentation. The ultrastructural analysis showed that the n umber of melanocytes was not significantly different in the different pigmented zones and the pigment transfer to adjacent keratinocytes was intact. There were three other girls in the kinhood and two, as well as a few other individuals in the family had a localized form of the d isease. Discussion. Universal dyschromatosis is a rare genodermatosis. The familial cases reported here illustrate the variable clinical pre sentations of this pigmentary abnormality. The pedigree in this family demonstrated incomplete penetrance of hereditary leukomelanoderma wit h autosomal dominant inheritance. The localized forms reported to date under different names would actually appear to correspond to incomple te expression of the dermatosis. The skin manifestations in universal dyschromatosis would appear to be similar to those in a few other skin diseases, mainly xeroderma pigmentosum, especially the localized form s; for generalized forms however, there is little room for confusion a s photosensitivity is absent and lesions predominate in unexposed zone s. The ultrastructure investigations showed different levels of melano cyte activity without abnormal pigment production or transfer. This ab normality has variable expression, explaining the multitude of clinica l presentations.