scholarly journals MC1R Mutations Modify the Classic Phenotype of Oculocutaneous Albinism Type 2 (OCA2)

2003 ◽  
Vol 73 (3) ◽  
pp. 638-645 ◽  
Author(s):  
Richard A. King ◽  
Rebecca K. Willaert ◽  
Ramona M. Schmidt ◽  
Jacy Pietsch ◽  
Sarah Savage ◽  
...  
Keyword(s):  
Oculocutaneous Albinism ◽  
Classic Phenotype

scholarly journals The distinctive geographic patterns of common pigmentation variants at the OCA2 gene

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Kenneth K. Kidd ◽  
Andrew J. Pakstis ◽  
Michael P. Donnelly ◽  
Ozlem Bulbul ◽  
Lotfi Cherni ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Oculocutaneous Albinism ◽  
Selection Effects ◽  
Nucleotide Polymorphism ◽  
Single Nucleotide ◽  
Eye Color ◽  
Geographic Patterns ◽  
Population Genetic Variation ◽  
Oca2 Gene

Abstract Oculocutaneous Albinism type 2 (OCA2) is a gene of great interest because of genetic variation affecting normal pigmentation variation in humans. The diverse geographic patterns for variant frequencies at OCA2 have been evident but have not been systematically investigated, especially outside of Europe. Here we examine population genetic variation in and near the OCA2 gene from a worldwide perspective. The very different patterns of genetic variation found across world regions suggest strong selection effects may have been at work over time. For example, analyses involving the variants that affect pigmentation of the iris argue that the derived allele of the rs1800407 single nucleotide polymorphism, which produces a hypomorphic protein, may have contributed to the previously demonstrated positive selection in Europe for the enhancer variant responsible for light eye color. More study is needed on the relationships of the genetic variation at OCA2 to variation in pigmentation in areas beyond Europe.

Type 2 oculocutaneous albinism (OCA2) in Zimbabwe and Cameroon: distribution of the 2.7-kb deletion allele of the P gene

1997 ◽  
Vol 100 (5-6) ◽  
pp. 651-656 ◽  
Author(s):  
Neelu Puri ◽  
Donna Durham-Pierre ◽  
Robert Aquaron ◽  
Patricia M. Lund ◽  
Richard A. King ◽  
...  
Keyword(s):  
Oculocutaneous Albinism ◽  
Deletion Allele ◽  
P Gene

A splice site mutation is the cause of the high prevalence of oculocutaneous albinism type 2 in the Kuna population

2009 ◽  
Vol 22 (5) ◽  
pp. 645-647 ◽  
Author(s):  
Androuw Carrasco ◽  
Elaine M. Forbes ◽  
Pascale Jeambrun ◽  
Murray H. Brilliant
Keyword(s):  
Splice Site ◽  
Splice Site Mutation ◽  
Oculocutaneous Albinism ◽  
Site Mutation ◽  
High Prevalence

scholarly journals Six Novel P Gene Mutations and Oculocutaneous Albinism Type 2 Frequency in Japanese Albino Patients

2003 ◽  
Vol 120 (5) ◽  
pp. 781-783 ◽  
Author(s):  
Tamio Suzuki ◽  
Yoshinori Miyamura ◽  
Jun Matsunaga ◽  
Hiroshi Shimizu ◽  
Yasuhiro Kawachi ◽  
...  
Keyword(s):  
Gene Mutations ◽  
Oculocutaneous Albinism ◽  
P Gene

scholarly journals Neonatal Oculocutaneous Albinism Type 2 With Prader-Willi Syndrome

2020 ◽  
Author(s):  
Gaohong Wu ◽  
Dongya Yan ◽  
Meijuan Zhou ◽  
Wenmei Li ◽  
Ping Jiang ◽  
...  
Keyword(s):  
Genetic Testing ◽  
Missense Mutation ◽  
High Throughput Sequencing ◽  
Clinical Signs ◽  
Clinical Manifestations ◽  
Oculocutaneous Albinism ◽  
Prader Willi Syndrome ◽  
White Skin ◽  
Feeding Difficulties

Abstract Background: To investigate the pathogenesis and clinical characteristics of Oculocutaneous albinism type 2 (OCA2), a genetic condition in the etiology of Prader-Willi syndrome (PWS).Case presentation: A retrospective study of one case presented with poor response to stimuli, difficultfeeding, poor crying, with yellow hair and white skin. We performed genetic testing and investigated disease pathogenesis, clinical manifestations, and diagnosis, and discussed the characteristics of the disease through a literature review. HiSeq high-throughput sequencing result suggested a deletion with 105 genes, including UBE3A, SNRPN, OCA2, and other genes up to 5.18 Mb on the long arm of chromosome (15q11-13 region), a critical region, susceptible to the PWS. A paternally derived deletion Del (15q11. 2q13. 1) [GRCh37 / hg19] (23, 378, 392-28, 563, 050) × 1, and a maternal missense mutation were identified in the OCA2 gene (chr15: 28171296 c .2056G> A (p.A686T). During the period of hospitalization, the child still suffered from poor milk intake, and she was discharged from the hospital at the request of her parents. After discharge, the patient was followed up for two months by telephone. However, the patient died of feeding difficulties and pulmonary infection.Conclusions: OCA2 combined with PWS due to OCA2 gene missense mutation combined with large fragment deletion of 15q11-13 region was first reported in this study, of which the clinical signs can be subtle and symptoms can be more severe, therefore, early genetic testing is crucial for those patients to yield an accurate diagnosis and initiate aggressive interventions to optimize the outcomes.

scholarly journals Mutational analysis of a Chinese family with oculocutaneous albinism type 2

Oncotarget ◽  
2017 ◽  
Vol 8 (41) ◽  
pp. 70345-70355
Author(s):  
Xiong Wang ◽  
Yaowu Zhu ◽  
Na Shen ◽  
Jing Peng ◽  
Chunyu Wang ◽  
...  
Keyword(s):  
Mutational Analysis ◽  
Oculocutaneous Albinism ◽  
Chinese Family

scholarly journals Localization to Mature Melanosomes by Virtue of Cytoplasmic Dileucine Motifs Is Required for Human OCA2 Function

2009 ◽  
Vol 20 (5) ◽  
pp. 1464-1477 ◽  
Author(s):  
Anand Sitaram ◽  
Rosanna Piccirillo ◽  
Ilaria Palmisano ◽  
Dawn C. Harper ◽  
Esteban C. Dell'Angelica ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Steady State ◽  
Subcellular Localization ◽  
Transmembrane Domain ◽  
Pigment Cell ◽  
Oculocutaneous Albinism ◽  
Melanin Synthesis ◽  
Sorting Motif ◽  
Domain Protein

Oculocutaneous albinism type 2 is caused by defects in the gene OCA2, encoding a pigment cell-specific, 12-transmembrane domain protein with homology to ion permeases. The function of the OCA2 protein remains unknown, and its subcellular localization is under debate. Here, we show that endogenous OCA2 in melanocytic cells rapidly exits the endoplasmic reticulum (ER) and thus does not behave as a resident ER protein. Consistently, exogenously expressed OCA2 localizes within melanocytes to melanosomes, and, like other melanosomal proteins, localizes to lysosomes when expressed in nonpigment cells. Mutagenized OCA2 transgenes stimulate melanin synthesis in OCA2-deficient cells when localized to melanosomes but not when specifically retained in the ER, contradicting a proposed primary function for OCA2 in the ER. Steady-state melanosomal localization requires a conserved consensus acidic dileucine-based sorting motif within the cytoplasmic N-terminal region of OCA2. A second dileucine signal within this region confers steady-state lysosomal localization in melanocytes, suggesting that OCA2 might traverse multiple sequential or parallel trafficking routes. The two dileucine signals physically interact in a differential manner with cytoplasmic adaptors known to function in trafficking other proteins to melanosomes. We conclude that OCA2 is targeted to and functions within melanosomes but that residence within melanosomes may be regulated by secondary or alternative targeting to lysosomes.

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