X-Linked Ocular Albinism

O'Donnell, Francis E.; Hambrick, George W.; Green, W. Richard; Iliff, W. Jackson; Stone, David L.

doi:10.1001/archopht.1976.03910040593001

Cited by 159 publications

(15 citation statements)

References 32 publications

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“…Therefore, we propose that OA1 may be involved in the establishment of coat color, of which the specific mechanism is as follows. The mutation of OA1 is responsible for the most common form of ocular albinism, in which patients exhibit a reduced number of enlarged melanosomes and visual defects [8,11,52]. OA1 performs two functions in melanogenesis, controlling the rate of melanosome biogenesis at early maturation stages and maintaining the correct melanosomal size at the final stage of the organellogenesis [53].…”

Section: Discussionmentioning

confidence: 99%

Ocular Albinism Type 1 Regulates Melanogenesis in Mouse Melanocytes

Chen

Wang

Liu

et al. 2016

IJMS

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To investigate whether ocular albinism type 1 (OA1) is differentially expressed in the skin of mice with different coat colors and to determine its correlation with coat color establishment in mouse, the expression patterns and tissue distribution characterization of OA1 in the skin of mice with different coat colors were qualitatively and quantitatively analyzed by real-time quantitative PCR (qRT-PCR), immunofluorescence staining and Western blot. The qRT-PCR analysis revealed that OA1 mRNA was expressed in all mice skin samples tested, with the highest expression level in brown skin, a moderate expression level in black skin and the lowest expression level in gray skin. Positive OA1 protein bands were also detected in all skin samples by Western blot analysis. The relative expression levels of OA1 protein in both black and brown skin were significantly higher than that in gray skin, but there was no significant difference between black and brown mice. Immunofluorescence assays revealed that OA1 was mainly expressed in the hair follicle matrix, the inner and outer root sheath in the skin tissues with different coat colors. To get further insight into the important role of OA1 in the melanocytes’ pigmentation, we transfected the OA1 into mouse melanocytes and then detected the relative expression levels of pigmentation-related gene. Simultaneously, we tested the melanin content of melanocytes. As a result, the overexpression of OA1 significantly increased the expression levels of microphthalmia-associated transcription factor (MITF), tyrosinase (TYR), tyrosinase-related protein 1 (TRP1) and premelanosome protein (PMEL). However, the tyrosinase-related protein 2 (TRP2) level was attenuated. By contrast, the level of glycoprotein non-metastatic melanoma protein b (GPNMB) was unaffected by OA1 overexpression. Furthermore, we observed a significant increase in melanin content in mouse melanocyte transfected OA1. Therefore, we propose that OA1 may participate in the formation of coat color by regulating the level of MITF and the number, size, motility and maturation of melanosome.

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Section: Discussionmentioning

confidence: 99%

Ocular Albinism Type 1 Regulates Melanogenesis in Mouse Melanocytes

Chen

Wang

Liu

et al. 2016

IJMS

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“…In general, OA1 is characterized by presence of photophobia, congenital nystagmus, strabismus, iris translucency, hypopigmentation of the ocular fundus, foveal hypoplasia, and impaired vision [23]. In African-American males, iris color is usually brown with little iris translucency (compared to Caucasians where iris translucency is more common) and individuals with darker skin may have scattered hypopigmented macules, but this is rarely seen in the skin of Caucasian individuals [24], [25]. The characteristics of OA1 have not been well defined in Asians.…”

Section: Discussionmentioning

confidence: 99%

A Novel Nonsense Mutation of the GPR143 Gene Identified in a Chinese Pedigree with Ocular Albinism

et al. 2012

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BackgroundThe purpose of this study was to elucidate the molecular basis of ocular albinism type I in a Chinese pedigree.Methodology/Principal FindingsComplete ophthalmologic examinations were performed on 4 patients, 7 carriers and 17 unaffected individuals in this five-generation family. All coding exons of four-point-one (4.1), ezrin, radixin, moesin (FERM) domain-containing 7 (FRMD7) and G protein-coupled receptor 143 (GPR143) genes were amplified by polymerase chain reaction (PCR), sequenced and compared with a reference database. Ocular albinism and nystagmus were found in all patients of this family. Macular hypoplasia was present in the patients including the proband. A novel nonsense hemizygous mutation c.807T>A in the GPR143 gene was identified in four patients and the heterozygous mutation was found in seven asymptomatic individuals. This mutation is a substitution of tyrosine for adenine which leads to a premature stop codon at position 269 (p.Y269X) of GPR143.Conclusions/SignificanceThis is the first report that p.Y269X mutation of GPR143 gene is responsible for the pathogenesis of familial ocular albinism. These results expand the mutation spectrum of GPR143, and demonstrate the clinical characteristics of ocular albinism type I in Chinese population.

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“…The occurrence of hyperpigmentation and large melanosomes in the human eye has been associated with two pigmentary disorders, ocular and oculodermal melanocytosis with and without uveal melanoma, and X‐linked ocular albinism (XLOA), respectively 10 –13 . Their occurrence is believed to be the result of an aberrant shift in melanogenic activity.…”

Section: Introductionmentioning

confidence: 99%

The influence of aging and low zinc nutrition on the choroid in the pig: I. The melanocyte

Lewis²,

MacKay³

et al. 1999

Veterinary Ophthalmology

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The effects of low zinc nutrition and aging on central choroidal melanocytes were examined in the pig. Three populations of pigs (young, pregnant and aged), were maintained on either control (C) or low zinc (LZ) diets. Twenty-five weanling boars were sacrificed at 2, 4, 8, 10, and 12-month intervals, and nine pregnant sows and eight aged sows were sacrificed after a 6-month interval. Melanocytes of the central choroid were morphologically and morphometrically examined. The melanocyte was found to be conservative in its form, which was mostly elliptical longitudinal profile, throughout the different age populations that were fed the C diet. Morphometric observations revealed that this cell type increased in size in the oldest animals, having been 40% greater than that in the younger two populations. However, the overall percentage area occupied by melanocytes remained the same throughout all age groups. In the animals that were fed the LZ diets, a large subpopulation of choroidal melanocytes was oval to round in shape in the pregnant and aged groups. Many members of this subpopulation possessed less opaque pigment than the elliptically shaped cell. Measurements of the size and percentage area occupied in these oldest groups increased significantly. In addition to the change of size, shape and melanin opaqueness, unusually large melanosomes were consistently observed in the pregnant and aged LZ groups. Low zinc nutrition had a remarkable age-related impact on the usually quiescent melanocyte.

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X-Linked Ocular Albinism

Cited by 159 publications

References 32 publications

Ocular Albinism Type 1 Regulates Melanogenesis in Mouse Melanocytes

Ocular Albinism Type 1 Regulates Melanogenesis in Mouse Melanocytes

A Novel Nonsense Mutation of the GPR143 Gene Identified in a Chinese Pedigree with Ocular Albinism

The influence of aging and low zinc nutrition on the choroid in the pig: I. The melanocyte

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