Dhar Shweta U, Robbins-Furman Patricia, Levy Moise L, Patel Ankita, Scaglia Fernando
Department of Molecular & Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA.
Am J Med Genet A. 2009 May;149A(5):993-6. doi: 10.1002/ajmg.a.32758.
Various forms of pigmentary dysplasias have been known to be associated with chromosomal mosaicism. One of these disorders, known as phylloid hypomelanosis, has been found to be predominantly associated with abnormalities in chromosome 13. Most of the reported literature involves mosaic trisomy 13 with clinical evidence of abnormal pigmentation in the form of leaf-like or oblong achromic macules following Blaschko's lines. Here, we report on an 8-year-old girl with phylloid hypomelanosis and precocious puberty who was found to have mosaicism for tetrasomy 13q in the form of inverted dup(13)(q21) on her skin fibroblasts as well as peripheral blood karyotype. A higher resolution (244K) chromosomal microarray was done on DNA from skin fibroblasts confirming the breakpoint and gain of distal 13q, which made her tetrasomic for 13q21-qter. This is the first-ever reported association of tetrasomy 13q with phylloid hypomelanosis and precocious puberty. Our report further emphasizes the need to exclude any type of abnormalities of chromosome 13 in patients with phylloid hypopigmentation.
已知多种形式的色素发育异常与染色体嵌合体有关。其中一种疾病，称为叶状色素减退症，已发现主要与13号染色体异常有关。大多数已报道的文献涉及13号染色体三体性嵌合体，临床表现为沿布拉斯科线出现叶状或长方形无色素斑形式的色素沉着异常。在此，我们报告一名8岁患有叶状色素减退症和性早熟的女孩，在其皮肤成纤维细胞以及外周血核型中发现存在13q四体性嵌合体，形式为倒位重复(13)(q21)。对皮肤成纤维细胞的DNA进行了更高分辨率(244K)的染色体微阵列分析，证实了断点以及13q远端的增加，这使得她在13q21-qter区域为四体。这是首次报道13q四体与叶状色素减退症和性早熟相关。我们的报告进一步强调，对于患有叶状色素减退的患者，需要排除13号染色体的任何类型异常。
