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Brown AE, Qiu CC, Drozd B, Sklover LR, Vickers CM, Hsu S. The color of skin: white diseases of the skin, nails, and mucosa. Clin Dermatol 2019; 37:561-579. [PMID: 31896410 DOI: 10.1016/j.clindermatol.2019.07.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
White diseases are a heterogenous group characterized by hypopigmentation or depigmentation. Skin and eye color are determined by the number and size of melanosomes present. Melanin is produced by melanosomes in the melanocytes present within the epidermis of the skin, uvea, and retinal pigmented epithelium (RPE). Conditions altering the number of melanocytes or concentration of melanin result in a lack of pigmentation, appearing as "white diseases" ranging from the well-known albinism and vitiligo to more esoteric white hand syndrome and Degos disease.
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Affiliation(s)
- Ashley E Brown
- McGovern Medical School, University of Texas Health Science Center at Houston,Houston, Texas, USA.
| | - Connie C Qiu
- Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, USA
| | - Brandy Drozd
- McGovern Medical School, University of Texas Health Science Center at Houston,Houston, Texas, USA
| | - Lindsay R Sklover
- Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, USA
| | - Conor M Vickers
- Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, USA
| | - Sylvia Hsu
- Department of Dermatology, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania, USA
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Extending the Mathematical Palette for Developmental Pattern Formation: Piebaldism. Bull Math Biol 2019; 81:1461-1478. [PMID: 30689102 DOI: 10.1007/s11538-019-00569-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 01/08/2019] [Indexed: 10/27/2022]
Abstract
Here, we present a theoretical investigation with potential insights on developmental mechanisms. Three biological factors, consisting of two diffusing factors and a cell-autonomous immobile transcription factor are combined with different feedback mechanisms. This results in four different situations or fur patterns. Two of them reproduce classical Turing patterns: (1) regularly spaced spots, (2) labyrinth patterns or straight lines with an initial slope in the activation of the transcription factor. The third situation does not lead to patterns, but results in different homogeneous color tones. Finally, the fourth one sheds new light on the possible mechanisms leading to the formation of piebald patterns exemplified by the random patterns on the fur of some cows' strains and Dalmatian dogs. Piebaldism is usually manifested as white areas of fur, hair, or skin due to the absence of pigment-producing cells in those regions. The distribution of the white and colored zones does not reflect the classical Turing patterns. We demonstrate that these piebald patterns are of transient nature, developing from random initial conditions and relying on a system's bistability. We show numerically that the presence of a cell-autonomous factor not only expands the range of reaction diffusion parameters in which a pattern may arise, but also extends the pattern-forming abilities of the reaction-diffusion equations.
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Hattori M, Ishikawa O, Oikawa D, Amano H, Yasuda M, Kaira K, Ishida-Yamamoto A, Nakano H, Sawamura D, Terawaki SI, Wakamatsu K, Tokunaga F, Shimizu A. In-frame Val 216-Ser 217 deletion of KIT in mild piebaldism causes aberrant secretion and SCF response. J Dermatol Sci 2018; 91:35-42. [PMID: 29631773 DOI: 10.1016/j.jdermsci.2018.03.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 03/14/2018] [Accepted: 03/18/2018] [Indexed: 11/16/2022]
Abstract
BACKGROUND Piebaldism is a pigmentary disorder characterized by a white forelock and depigmented patches. Although the loss-of-function mutations in the KIT gene underlie the disease, the intracellular dynamics of the mutant KIT are largely unknown. We herein report a Japanese family with piebaldism in which the affected members showed a mild phenotype. OBJECTIVE The objective of this study is to investigate the functions and intracellular dynamics of the mutant KIT protein. METHODS We performed genetic analyses of the KIT gene using peripheral blood cells. We analyzed the intracellular localization of the mutant KIT protein in HEK293T cells transfected with wild-type (Wt) and/or mutant KIT genes. Immunoprecipitation analyses, immunoblotting and immunofluorescence studies were performed using antibodies against KIT and downstream signaling proteins. Glycosidase digestion analysis was performed to clarify the intracellular localization of KIT protein. RESULTS A genetic analysis revealed a novel heterozygous mutation c.645_650delTGTGTC which results in the in-frame deletion of Val216 and Ser217 in the extracellular domain of KIT. Immunoprecipitation analyses confirmed that the wild and mutant KIT formed a heterodimer after treatment with stem cell factor (SCF); however, the phosphorylation of the downstream signaling factors was decreased. In an immunofluorescence study, the mutant KIT accumulated predominantly in the endoplasmic reticulum (ER) and was sparsely expressed on the cell surface. A glycosidase digestion study revealed that the mutant KIT is predominantly localized in the ER. CONCLUSION These data reveal an aberrant function and intracellular localization of mutant KIT protein in piebaldism.
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Affiliation(s)
- Mai Hattori
- Department of Dermatology, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan; Department of Dermatology, Japan Red Cross Maebashi Hospital, Maebashi, Japan
| | - Osamu Ishikawa
- Department of Dermatology, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan
| | - Daisuke Oikawa
- Department of Pathobiochemistry, Graduate School of Medicine, Osaka City University, Osaka, Japan
| | - Hiroo Amano
- Department of Dermatology, Iwate Medical University, Morioka, Iwate, Japan
| | - Masahito Yasuda
- Department of Dermatology, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan
| | - Kyoichi Kaira
- Department of Oncology Clinical Development, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan
| | | | - Hajime Nakano
- Department of Dermatology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, Japan
| | - Daisuke Sawamura
- Department of Dermatology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, Japan
| | - Shin-Ichi Terawaki
- Graduate School of Science and Technology, Gunma University, Kiryu, Gunma, Japan
| | - Kaori Wakamatsu
- Graduate School of Science and Technology, Gunma University, Kiryu, Gunma, Japan
| | - Fuminori Tokunaga
- Department of Pathobiochemistry, Graduate School of Medicine, Osaka City University, Osaka, Japan
| | - Akira Shimizu
- Department of Dermatology, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan.
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El Kouarty H, Dakhama BSB. [Piebaldism: a pigmentary anomaly to recognize: about a case and review of the literature]. Pan Afr Med J 2016; 25:155. [PMID: 28292117 PMCID: PMC5326035 DOI: 10.11604/pamj.2016.25.155.10499] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 10/13/2016] [Indexed: 11/11/2022] Open
Abstract
Piebaldism is a rare autosomal dominant disorder characterized by an abnormal congenital skin pigmentation causing hypopigmented areas. It is due to an abnormal melanocytes development. It usually affects only the skin, but it may be associated with other anomalies or confused with other differential diagnoses. We report the case of a 5-year old boy with piebaldism having a family history of dermatologic phenotype without other alterations. We here highlight the pathogenesis, clinical manifestations, differential diagnosis as well as the management techniques and new therapeutic trials.
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Affiliation(s)
- Hajar El Kouarty
- Service des Urgences Médicales Pédiatriques, Hôpital d'Enfants Rabat, Faculté de Médecine et de Pharmacie, Université Mohammed V, Rabat, Maroc
| | - Badr Sououd Benjelloun Dakhama
- Service des Urgences Médicales Pédiatriques, Hôpital d'Enfants Rabat, Faculté de Médecine et de Pharmacie, Université Mohammed V, Rabat, Maroc
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