Genetic Hypomelanoses: Generalized Hypopigmentation

King, Richard A.; Oetting, William S.; Bahadoran, Philippe; Ortonne, Jean Paul; Gadenne, Anne Sophie; Nordlund, James J.; Titsch, Marnie D.; Mineroff, Allan D.; Bolognia, Jean L.; Ploysangam, Tanusin

doi:10.1002/9780470987100.ch31

Cited by 7 publications

(5 citation statements)

References 334 publications

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“…No patients had undiagnosed HPS1 or HPS4, and none had mutations of SILV, a candidate OCA gene. These findings thus indicate that, contrary to long-standing clinical lore (King et al, 2001(King et al, , 2007King and Oetting, 2006), among Caucasian patients with OCA, the great majority has OCA1. Virtually none have OCA3.…”

Section: Discussionmentioning

confidence: 67%

“…The prevalences of the different OCA disorders vary widely among different populations. Among African and African-American OCA patients, OCA2 and, to a lesser extent, OCA3 are most frequent (King et al, 2001(King et al, , 2007King and Oetting, 2006). Among Puerto Rican patients, HPS1 and HPS4 are most frequent.…”

Section: Introductionmentioning

confidence: 99%

“…Among Puerto Rican patients, HPS1 and HPS4 are most frequent. Among Caucasian patients, clinical lore and genetics textbooks have long held that OCA2 is the most frequent form of OCA (King et al, 2001(King et al, , 2007King and Oetting, 2006); however, the original evidence underlying this assertion is difficult to ascertain. Virtually all published studies have described molecular analysis of OCA patients on a gene-by-gene basis, with few systematic analyses of different genetic causes of OCA in any population, and none in non-Hispanic Caucasian patients.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Comprehensive Analysis of Oculocutaneous Albinism among Non-Hispanic Caucasians Shows that OCA1 Is the Most Prevalent OCA Type

Hutton

Spritz

2008

Journal of Investigative Dermatology

109

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Oculocutaneous albinism (OCA) is a genetically heterogeneous group of disorders characterized by absent or reduced pigmentation of the skin, hair, and eyes. In humans, four genes have been associated with "classical" OCA and another 12 genes with syndromic forms of OCA. To assess the prevalence of different forms of OCA and different gene mutations among non-Hispanic Caucasian patients, we performed DNA sequence analysis of the four genes associated with "classical" OCA (TYR, OCA2, TYRP1, SLC45A2), the two principal genes associated with syndromic OCA (HPS1, HPS4), and a candidate OCA gene (SILV), in 121 unrelated, unselected non-Hispanic/Latino Caucasian patients carrying the clinical diagnosis of OCA. We identified apparent pathologic TYR gene mutations in 69% of patients, OCA2 mutations in 18%, SLC45A2 mutations in 6%, and no apparent pathological mutations in 7% of patients. We found no mutations of TYRP1, HPS1, HPS4, or SILV in any patients. Although we observed a diversity of mutations for each gene, a relatively small number of different mutant alleles account for a majority of the total. This study demonstrates that, contrary to long-held clinical lore, OCA1, not OCA2, is by far the most frequent cause of OCA among Caucasian patients.

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Section: Discussionmentioning

confidence: 67%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Comprehensive Analysis of Oculocutaneous Albinism among Non-Hispanic Caucasians Shows that OCA1 Is the Most Prevalent OCA Type

Hutton

Spritz

2008

Journal of Investigative Dermatology

109

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“…Chediak-Higashi syndrome, besides hypopigmentation, can manifest with hematologic changes, high susceptibility to infections, bleeding, and neurological problems 13, 14, 15, 16, 17. Albinism can also be expressed by the exclusively ocular form (OA1 and FHONDA syndrome) 5, 18, 19…”

Section: Albinism Types and Epidemiologymentioning

confidence: 99%

Albinism: epidemiology, genetics, cutaneous characterization, psychosocial factors

Marçon

Maia

2019

Anais Brasileiros de Dermatologia

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Oculocutaneous albinism is an autosomal recessive disease caused by the complete absence or decrease of melanin biosynthesis in melanocytes. Due to the reduction or absence of melanin, albinos are highly susceptible to the harmful effects of ultraviolet radiation and are at increased risk of actinic damage and skin cancer. In Brazil, as in other parts of the world, albinism remains a little known disorder, both in relation to epidemiological data and to phenotypic and genotypic variation. In several regions of the country, individuals with albinism have no access to resources or specialized medical care, and are often neglected and deprived of social inclusion. Brazil is a tropical country, with a high incidence of solar radiation during the year nationwide. Consequently, actinic damage and skin cancer occur early and have a high incidence in this population, often leading to premature death. Skin monitoring of these patients and immediate therapeutic interventions have a positive impact in reducing the morbidity and mortality associated with this condition. Health education is important to inform albinos and their families, the general population, educators, medical professionals, and public agencies about the particularities of this genetic condition. The aim of this article is to present a review of the epidemiological, clinical, genetic, and psychosocial characteristics of albinism, with a focus in skin changes caused by this rare pigmentation disorder.

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“…Oculocutaneous albinism (OCA) is an autosomal-recessive condition characterized by reduced pigmentation of the hair, skin, and eyes (1,2). Common ocular features of OCA include iris transillumination, nystagmus, foveal hypoplasia, and reduced best-corrected visual acuity; children have varying degrees of visual impairment and can be legally blind.…”

Section: Introductionmentioning

confidence: 99%

Nitisinone improves eye and skin pigmentation defects in a mouse model of oculocutaneous albinism

Onojafe¹,

Adams²,

Simeonov³

et al. 2011

J. Clin. Invest.

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Mutation of the tyrosinase gene (TYR) causes oculocutaneous albinism, type 1 (OCA1), a condition characterized by reduced skin and eye melanin pigmentation and by vision loss. The retinal pigment epithelium influences postnatal visual development. Therefore, increasing ocular pigmentation in patients with OCA1 might enhance visual function. There are 2 forms of OCA1, OCA-1A and OCA-1B. Individuals with the former lack functional tyrosinase and therefore lack melanin, while individuals with the latter produce some melanin. We hypothesized that increasing plasma tyrosine concentrations using nitisinone, an FDA-approved inhibitor of tyrosine degradation, could stabilize tyrosinase and improve pigmentation in individuals with OCA1. Here, we tested this hypothesis in mice homozygous for either the Tyr c-2J null allele or the Tyr c-h allele, which model OCA-1A and OCA-1B, respectively. Only nitisinone-treated Tyr c-h/c-h mice manifested increased pigmentation in their fur and irides and had more pigmented melanosomes. High levels of tyrosine improved the stability and enzymatic function of the Tyr c-h protein and also increased overall melanin levels in melanocytes from a human with OCA-1B. These results suggest that the use of nitisinone in OCA-1B patients could improve their pigmentation and potentially ameliorate vision loss.

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Genetic Hypomelanoses: Generalized Hypopigmentation

Cited by 7 publications

References 334 publications

Comprehensive Analysis of Oculocutaneous Albinism among Non-Hispanic Caucasians Shows that OCA1 Is the Most Prevalent OCA Type

Comprehensive Analysis of Oculocutaneous Albinism among Non-Hispanic Caucasians Shows that OCA1 Is the Most Prevalent OCA Type

Albinism: epidemiology, genetics, cutaneous characterization, psychosocial factors

Nitisinone improves eye and skin pigmentation defects in a mouse model of oculocutaneous albinism

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