Reisenauer A K, Wordingham S V, York J, Kokkonen E W J, Mclean W H I, Wilson N J, Smith F J D
Kaiser Permanente, 1279 S. Kihei Rd, Kihei, HI, U.S.A.
Br J Dermatol. 2014 Jun;170(6):1362-5. doi: 10.1111/bjd.12813.
Reticulate pigmentary disorders include the rare autosomal dominant Galli-Galli disease (GGD) and Dowling-Degos disease (DDD). Clinical diagnosis between some of the subtypes can be difficult due to a degree of overlap between clinical features, therefore analysis at the molecular level may be necessary to confirm the diagnosis.
To identify the underlying genetic defect in a 48-year-old Asian-American woman with a clinical diagnosis of GGD.
Histological analysis was performed on a skin biopsy using haematoxylin-eosin staining. KRT5 (the gene encoding keratin 5) was amplified from genomic DNA and directly sequenced.
The patient had a history of pruritus and hyperpigmented erythematous macules and thin papules along the flexor surfaces of her arms, her upper back and neck, axillae and inframammary areas. Hypopigmented macules were seen among the hyperpigmentation. A heterozygous 1-bp insertion mutation in KRT5 (c.38dupG; p.Ser14GlnfsTer3) was identified in the proband. This mutation occurs within the head domain of the keratin 5 protein leading to a frameshift and premature stop codon.
From the histological findings and mutation analysis the individual was identified as having GGD due to haploinsufficiency of keratin 5.
网状色素沉着性疾病包括罕见的常染色体显性遗传性加里 - 加里病（GGD）和道林 - 迪戈斯病（DDD）。由于某些亚型的临床特征存在一定程度的重叠，临床诊断可能会有困难，因此可能需要进行分子水平的分析来确诊。
确定一名临床诊断为GGD的48岁亚裔美国女性潜在的基因缺陷。
使用苏木精 - 伊红染色对皮肤活检标本进行组织学分析。从基因组DNA中扩增KRT5（编码角蛋白5的基因）并直接测序。
该患者有瘙痒病史，其手臂屈侧、上背部和颈部、腋窝及乳房下区域有色素沉着性红斑丘疹和薄丘疹。色素沉着区域可见色素减退斑。在先证者中鉴定出KRT5基因杂合的1个碱基插入突变（c.38dupG；p.Ser14GlnfsTer3）。该突变发生在角蛋白5蛋白的头部结构域内，导致移码和提前终止密码子。
根据组织学检查结果和突变分析，该个体被确定因角蛋白5单倍体不足而患有GGD。
