PDF(Pubmed)
Abstract：
Congenital dermal melanocytosis (DM) represents a common birthmark mainly found in children of Asian and darker skin phototype descent, clinically characterized by an oval blue-grey macule or macules, commonly located on the lumbosacral area. In rare DM cases, when presenting with diffuse macules persisting during the first years of life, it could represent a cutaneous feature of mucopolysaccharidoses (MPS). Extensive congenital DM is actually associated with Hurler syndrome (MPS type I) and Hunter syndrome (MPS type II), although several reports also described this association with MPS type VI and other lysosomal storage disorders (LySD), including GM1 gangliosidosis, mucolipidosis, Sandhoff disease, and Niemann-Pick disease. Here, we present the case of a two-year-old boy presenting with extensive dermal melanocytosis, generalized hypertrichosis, and chronic itch, harboring a heterozygous variant of uncertain significance, NM_152419.3: c.493C>T (p.Pro165Ser), in the exon 4 of HGSNAT gene, whose mutations are classically associated with MPS IIIC, also known as Sanfilippo syndrome. This is the first report that highlights the association between extensive congenital DM and MPS type IIIC, as well as a pathogenetic link between heterozygous LySD carrier status and congenital DM. We speculate that some cases of extensive congenital DM could be related to heterozygous LySD carriers, as a manifestation of a mild clinical phenotype.
摘要：
先天性真皮黑素细胞增多症（DM）是一种常见的胎记，主要存在于亚洲和深色肤色的儿童中。临床特征为椭圆形蓝灰色斑疹或斑疹，通常位于腰骶部。在罕见的DM病例中，当表现为在生命的最初几年持续存在的弥漫性黄斑时，它可以代表粘多糖（MPS）的皮肤特征。广泛的先天性DM实际上与Hurler综合征（MPSI型）和Hunter综合征（MPSII型）有关，尽管一些报道也描述了这种关联与MPSVI型和其他溶酶体贮积症（LySD），包括GM1神经节苷脂，粘脂症,桑霍夫病,和尼曼-皮克病.这里,我们介绍了一个两岁男孩表现出广泛的真皮黑素细胞增多症，全身性多毛症,和慢性瘙痒，具有不确定意义的杂合变体，NM_152419.3：c.493C>T（p。Pro165Ser),在HGSNAT基因的外显子4中，其突变与MPSIIIC经典相关，也被称为Sanfilippo综合征。这是第一份报告，强调广泛的先天性DM和MPS型IIIC之间的关联，以及杂合型LySD携带者状态与先天性DM之间的致病联系。我们推测，一些广泛的先天性DM病例可能与杂合性LySD携带者有关，作为轻度临床表型的表现。
