Leukoderma in patients with atopic dermatitis.

Atopic dermatitis (AD) is occasionally associated with vitiligo, however, the incidence and conditions of vitiligo or leukoderma, and the characteristics of concurrent AD, remain unclear. We conducted a prospective observational study to investigate the leukoderma-related clinical manifestations and bioparameters of AD. Because vitiligo in AD lesions is occasionally associated with inflammation, we used leukoderma in this study. Enrolled were all AD patients who had been followed up in our AD outpatient clinic and visited within the previous 4 months. During this period, we carefully inspected whether the patients had leukoderma. Eight of 52 patients had leukoderma (15.4%) and were designated as the leukoderma group, and the remaining 44 patients comprised the non-leukoderma group. While the ages were statistically not different between the two groups, female preponderance was significantly observed in the leukoderma group. The leukoderma patients tended to have higher values of SCORAD, CCL17/thymus and activation regulated chemokine and lactate dehydrogenase than the non-leukoderma patients. The leukoderma group was also characterized by a lower frequency of allergic rhinitis and a higher frequency of prurigo lesions. Thus, despite the possession of high AD severity, the leukoderma patients may possibly retain a relatively T-helper 1-skewing state in relation to the development of leukoderma and less association with rhinitis.

aCGH detects partial tetrasomy of 12p in blood from Pallister-Killian syndrome cases without invasive skin biopsy.

Pallister-Killian syndrome (PKS) is a genetic disorder characterized by mental retardation, seizures, streaks of hypo- or hyperpigmentation and dysmorphic features. PKS is associated with tissue-limited mosaic partial tetrasomy of 12p, usually caused by an isochromosome 12p. The mosaicism is usually detected in cultured skin fibroblasts or amniotic cells and rarely in phytohemagluttinin-stimulated lymphocytes, which suggests stimulation of T-lymphocytes may distort the percentage of abnormal cells. We recently reported on the identification by microarray-based comparative genomic hybridization (aCGH) of a previously unsuspected case of partial tetrasomy of 12p caused by an isochromosome 12p. Here we report on seven additional individuals with partial tetrasomy of 12p characterized by our laboratory. All individuals were referred for mental retardation/developmental delay and/or dysmorphic features. In each case, aCGH using genomic DNA extracted from whole peripheral blood detected copy-number gain for all clones for the short arm of chromosome 12. In all but one case, FISH on metaphases from cultured lymphocytes did not detect the copy-number gain; in the remaining case, metaphase FISH on cultured lymphocytes showed an isochromosome in 10% of cells. However, interphase FISH using probes to 12p on peripheral blood smears showed additional hybridization signals in 18-70% of cells. Microarray and FISH analysis on cultured skin biopsies from four individuals confirmed the presence of an isochromosome 12p. Our results demonstrate the usefulness of aCGH with genomic DNA from whole peripheral blood to detect chromosome abnormalities that are not present in stimulated blood cultures and would otherwise require invasive skin biopsies for identification.