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 Printable version |
Phylloid hypomelanosis is closely related
to mosaic trisomy 13 |
European Journal of Dermatology. Volume 10, Number 7, 511-2, October - November 2000, Gènes et peau
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 Free Article
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Author(s) : R. Happle |
Summary : Phylloid hypomelanosis is a distinct type of pigmentary mosaicism characterized by congenital hypochromic macules resembling a floral ornament with various elements such as round or oval patches, macules resembling the asymmetrical leaves of a begonia, or oblong lesions. A review of cases with documentation of cytogenetic findings showed that aberrations involving chromosome 13 were present in 5 out of 6 patients. Examination of blood lymphocytes revealed a 46, XX/47 XX, +13 or 46, XX/47, XX, +der (13) mosaic in three of these cases and a karyotype 46, XX, t(13;13) in the other two cases. Cytogenetic analysis of skin fibroblasts showed chromosomal mosaicism in 4 of the 5 patients. In the remaining case, a chromosome 13 translocated on 13 was found in 100% of blood lymphocytes and skin fibroblasts, suggesting that mosaicism involving chromosome 13 may have developed in the melanocyte system. In conclusion, contrasting with hypomelanosis of Ito which is a cutaneous sign of many different states of mosaicism, phylloid hypomelanosis seems to originate preponderantly from a mosaic state involving chromosome 13. Future case reports may help to delineate further the significance of this relationship. |
Keywords : pigmentary mosaicism, chromosomal aberrations, trisomy 13, phylloid pattern, hypomelanosis of Ito. |
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