introduction oculocutaneous albinism (oca) is a genetically heterogeneous autosomal recessive genetic disorder that is characterized by reduced or completely absent pigmentation in the hair, skin, and eyes. conclusions a novel homozygous mutation, the deletion of exons 1 - 5 on the tyr gene, was found on the molecular genetic testing of this patient. exon 1 - 5 deletion on tyr causes a lack of ...

Background & Aims: Tyrosinase is the most important enzyme in the production of pigments of the skin, eyes, and hair follicles. The enzyme is encoded by tyrosinase gene (TYR) or oculocutaneous albinism type 1A (OCA1A). Mutations in TYR gene result in pigmentation disorders such as albinism in humans. In view of the large number of mutations reported in this gene, the aim of this study was to id...

retinal pigment epithelium is responsible for maintaining the structural integrity of the retina by an efficient defense against free radicals, photo-oxidative exposure and light energy. for this purpose the main rpe line of defense is melanosomes. melanin content of retinal pigment epithelium cells in adults and neonates reveals remarkable variations. in the current study we compared melanogen...

background: oculocutaneous albinism type1 (oca1) is characterized by the absence of melanin pigmentation. the muta­tion on tyr gene makes oca1 as an autosomal recessive genetic disorder. in this study, we delineated the genetic analysis of an iranian family with four members affected with oca1.  methods: clinical exams and paraclinical test were performed for all patients of the case family, al...

Abstract Objective Phenylketonuria (PKU) is caused by a specific mutation of the phenylalanine hydroxylase (PAH) gene. The deficiency PAH results in high levels (Phe), low tyrosine (Tyr), and reduced catecholamine neurotransmitters. majority PKU patients, if untreated, develop severe mental retardation. contribution Phe Tyr retardation largely unknown. In this study, we used organic hippocampal...

The human tyrosinase gene TYR is a multifunctional reporter gene with potential use in photoacoustic imaging (PAI), positron emission tomography (PET), and magnetic resonance imaging (MRI). We sought to establish and evaluate a reporter gene system using TYR under the control of the Tet-on gene expression system (gene expression induced by doxycycline [Dox]) as a multimodality imaging agent. We...

TYR, DCT and MITF are three important genes involved in maintaining the mature phenotype and producing melanin; they therefore participate in neural crest cell development into melanocytes. Previous studies have revealed that the Wnt signaling factor lymphoid enhancer-binding factor (LEF-1) can enhance DCT and MITF gene expression. However, whether LEF-1 also affects TYR gene expression remains...

BACKGROUND Oculocutaneous albinism (OCA) is an autosomal recessive disorder. The most common type OCA1 and OCA2 are caused by homozygous or compound heterozygous mutations in the tyrosinase gene (TYR) and OCA2 gene, respectively. OBJECTIVE The purpose of this study was to evaluate the molecular basis of oculocutaneous albinism in four Chinese families. PATIENTS AND METHODS Four non-consangu...