title: Mutations in POFUT1, encoding protein O-fucosyltransferase 1, cause generalized Dowling-Degos disease.
abstract: Dowling-Degos disease (DDD), or reticular pigmented anomaly of the flexures, is a type of rare autosomal-dominant genodermatosis characterized by reticular hyperpigmentation and hypopigmentation of the flexures, such as the neck, axilla, and areas below the breasts and groin, and shows considerable heterogeneity. Loss-of-function mutations of keratin 5 (KRT5) have been identified in DDD individuals. In this study, we collected DNA samples from a large Chinese family affected by generalized DDD and found no mutation of KRT5. We performed a genome-wide linkage analysis of this family and mapped generalized DDD to a region between rs1293713 and rs244123 on chromosome 20 [corrected]. By exome sequencing, we identified nonsense mutation c.430G>T (p.Glu144(∗)) in POFUT1, which encodes protein O-fucosyltransferase 1, in the family. Study of an additional generalized DDD individual revealed the heterozygous deletion mutation c.482delA (p.Lys161Serfs(∗)42) in POFUT1. Knockdown of POFUT1 reduces the expression of NOTCH1, NOTCH2, HES1, and KRT5 in HaCaT cells. Using zebrafish, we showed that pofut1 is expressed in the skin and other organs. Morpholino knockdown of pofut1 in zebrafish produced a phenotype characteristic of hypopigmentation at 48 hr postfertilization (hpf) and abnormal melanin distribution at 72 hpf, replicating the clinical phenotype observed in our DDD individuals. At 48 and 72 hpf, tyrosinase activities decreased by 33% and 45%, respectively, and melanin protein contents decreased by 20% and 25%, respectively. Our findings demonstrate that POFUT1 mutations cause generalized DDD. These results strongly suggest that the protein product of POFUT1 plays a significant and conserved role in melanin synthesis and transport.
authors.affiliation: Department of Dermatology, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200092, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.forename: Ruhong
authors.initials: R
authors.lastname: Cheng
authors.forename: Jianying
authors.initials: J
authors.lastname: Liang
authors.forename: Heng
authors.initials: H
authors.lastname: Yan
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.forename: Lijia
authors.initials: L
authors.lastname: Yang
authors.forename: Chengrang
authors.initials: C
authors.lastname: Li
authors.forename: Qingqing
authors.initials: Q
authors.lastname: Jiao
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Lu
authors.forename: Jianhui
authors.initials: J
authors.lastname: He
authors.forename: Jin
authors.initials: J
authors.lastname: Ji
authors.forename: Zhu
authors.initials: Z
authors.lastname: Shen
authors.forename: Chunqi
authors.initials: C
authors.lastname: Li
authors.forename: Fei
authors.initials: F
authors.lastname: Hao
authors.forename: Hong
authors.initials: H
authors.lastname: Yu
authors.forename: Zhirong
authors.initials: Z
authors.lastname: Yao
mesh_terms: D000818:Animals; D002874:Chromosome Mapping; D002890:Chromosomes, Human, Pair 20 / Q000235:genetics; D005260:Female; D005647:Fucosyltransferases / Q000235:genetics*; D015870:Gene Expression; D055785:Gene Knockdown Techniques; D008040:Genetic Linkage; D020022:Genetic Predisposition to Disease; D055106:Genome-Wide Association Study; D057809:HEK293 Cells; D006801:Humans; D017495:Hyperpigmentation / Q000235:genetics* / Q000473:pathology; D008543:Melanins / Q000096:biosynthesis / Q000235:genetics; D008875:Middle Aged; D020125:Mutation, Missense; D010375:Pedigree; D020641:Polymorphism, Single Nucleotide; D017422:Sequence Analysis, DNA; D012873:Skin Diseases, Genetic / Q000235:genetics* / Q000473:pathology; D017444:Skin Diseases, Papulosquamous / Q000235:genetics* / Q000473:pathology; D015027:Zebrafish; D029961:Zebrafish Proteins / Q000096:biosynthesis / Q000235:genetics
chemical_list: D008543:Melanins; D029961:Zebrafish Proteins; D005647:Fucosyltransferases; C105148:polypeptide fucosyltransferase