Research progress of FYCO1 gene mutation / 中华实验眼科杂志

FYVE and coiled-coil domain containing 1(FYCO1) is an adaptor of cellular autophagy which has RUN domain,coiled coil domain,FYVE domain,GOLD domain and LIR domain. FYCO1 protein is widely expressed and mainly interacts with Atg8 family proteins,microtubule-based kinesins,phosphatidylinositol-3-phosphate (PI3P). The FYCO1 protein involved in the movement of kinesins along microtubules and the microtubule plus end-directed transport of autophagy vesicles and related to the development and transparency maintenance of human lens. FYCO1 mutations are one of the causes inducing autosomal recessive congenital cataract. Mutations of FYCO1 can inhibit the process of autophagosome transport to lysosomes,leading to the failure of mitochondrial and other organelle degradation processes in lens fibroblasts and causing opacity of the lens. Eighteen cataract-related mutations have been identified in FYCO1 currently. In addition,FYCO1 protein plays an important role in life processes,such as cell division,and is associated with various diseases,such as Parkinson's disease,cancer,sporadic inclusion body myositis and keloid. This article reviewed the current research progress of FYCO1 gene mutations.

Research progress of FYCO1 gene mutation / 中华实验眼科杂志

FYVE and coiled-coil domain containing 1(FYCO1) is an adaptor of cellular autophagy which has RUN domain, coiled coil domain, FYVE domain, GOLD domain and LIR domain.FYCO1 protein is widely expressed and mainly interacts with Atg8 family proteins, microtubule-based kinesins, phosphatidylinositol-3-phosphate (PI3P). The FYCO1 protein involved in the movement of kinesins along microtubules and the microtubule plus end-directed transport of autophagy vesicles and related to the development and transparency maintenance of human lens.FYCO1 mutations are one of the causes inducing autosomal recessive congenital cataract.Mutations of FYCO1 can inhibit the process of autophagosome transport to lysosomes, leading to the failure of mitochondrial and other organelle degradation processes in lens fibroblasts and causing opacity of the lens.Eighteen cataract-related mutations have been identified in FYCO1 currently.In addition, FYCO1 protein plays an important role in life processes, such as cell division, and is associated with various diseases, such as Parkinson's disease, cancer, sporadic inclusion body myositis and keloid.This article reviewed the current research progress of FYCO1 gene mutations.

Alterações detectadas pelo teste do reflexo vermelho / Ocular findings by using red-reflex testing

Objetivo: A leucocoria é a presença da pupila branca e deve ser investigada e diagnosticada o mais precoce possível. A realização do Teste do Reflexo Vermelho, ao nascimento, permite a triagem de patologias importantes como a catarata congênita e o retinoblastoma. Este estudo tem como objetivo avaliar a prevalência de alterações oculares diagnosticada através do teste do reflexo vermelho em pacientes nascidos em uma maternidade do sul do Brasil. Métodos: Realizado estudo retrospectivo, transversal através da análise de prontuários no período de agosto de 2007 a maio 2011. Foram avaliados 10135 pacientes recém nascidos, antes da alta da maternidade. Todos os pacientes realizaram o teste do reflexo vermelho. Foi considerado alterado o teste em que o reflexo vermelho não esteve presente. Resultados: Foram detectados 4 pacientes com catarata congênita (prevalência de 4/10.000). Também foram observados um caso de coloboma de iris e um caso de albinismo ocular. Conclusão: O estudo concluiu que a prevalência das alterações encontradas corroboram com outros estudos da literatura.

Objetive: Leukocoria is the presence of the white pupil and should be investigated and diagnosed as early as possible . The Red Reflex Test should be done at birth because it allows the screening of important diseases such as congenital cataract and retinoblastoma. This study aims to evaluate the prevalence of ocular abnormalities using the red reflex test in patients born in a maternity hospital in southern Brazil. Methods: Retrospective, transversal study through analysis of medical records from August 2007 to May 2011. We analysed 10135 medical records. All newborn patients were submitted to Red-Reflex examination before leaving the hospital. The testing was considered abnormal when the red reflex was not present. Results: During the period of the study, congenital cataract was detected in 4 patients (prevalence of 4/10.000). We were also observed 1 case of coloboma of iris and 1 case of ocular albinism. Conclusions: The study concluded that prevalence of ocular findings corroborate with other studies in the literature.

Two Cases of Oculocerebrorenal Syndrome in Two Brothers Diagnosed after Congenital Cataract Surgery

PURPOSE: We report two cases of brothers diagnosed with oculocerebrorenal syndrome after binocular congenital cataract surgery. METHODS: Two brothers who had undergone surgeries for congenital cataracts showed growth retardation, proteinuria, and generalized tonic seizures. The patients were referred to the pediatrics department and evaluated for systemic diseases and genetic counseling. RESULTS: Two brothers had renal tubular dysfunction characterized by hypercalciuria and hyperphosphaturia. The older brother had multiple microcalcifications on both kidneys, and ischemic injury with general dysfunction of the brain. Genetic analysis of brothers and their mother showed a new mutation of P799L in the region of the chromosome Xq25-26.1 locus. The two brothers were diagnosed with oculocerebrorenal syndrome of Lowe (OCRL). CONCLUSIONS: In cases of patients with congenital cataracts, the evaluation of systemic disease including genetic abnormality should be considered whenever systemic symptoms such as growth retardation, proteinuria or seizure are found.

Genetic Analysis Of Congenital Cataracts.

Congenital cataracts constitute a major cause of blindness in infancy. It is caused by the loss of transparency of the lens, hampering normal vision. Affected infants become visually handicapped necessitating effective management. Cataracts result when normal lens formation during embryogenesis and its subsequent development are affected. Based on the location and morphology of the opacities, different phenotypic forms of cataracts are identified which are under the control of different genes and follow autosomal dominant, autosomal recessive and X-linked inheritance. Crystallins (a, b and g) which constitute 90% of the water soluble proteins are responsible for the maintenance of the refractive property of the lens. Hence structural variations in these proteins have been associated with cataracts. Intrinsic membrane proteins which are water insoluble and expressed in the terminal differentiation of the lens epithelium are also implicated in cataract formation. Cataracts are found to be associated with maternal infections during pregnancy (rubella infection), several clinical syndromes, metabolic disorders, chromosomal disorders, (triploidy, trisomies, monosomy, deletions, duplications and translocations), and gene disorders. Autosomal dominant forms are found to be more common among the gene disorders and exhibit intrafamilial, interfamilial and interocular variations. More than a dozen genes have been mapped for cataracts showing the locus and allelic heterogeneity and two of them are associated with mutations in the crystallin genes. One of them with over expression of gE gene on chromosome 2 causes Coppock like cataract while a chain termination mutation in the crystallin BB2 locus on chromosome 22 causes Cerulean cataract. Experiments on animals suggest crystallins as strong candidates for the study of cataracts in man. Other candidate loci include intrinsic membrane proteins (MIP), developmental genes (PAX6) and connexin gap junction proteins (CX46). Surgical extraction of cataracts though is considered as the best treatment for cataracts, the prognosis is poor when it comes to infantile forms. Hence risk predictions and counseling based on the mode of inheritance and other factors seems to be the best approach in the management of cataracts. Recently prenatal detection of cataracts through ultrasonography has been reported which can be made a part of the routine anatomical study specially when family history for severe genetic disorder assoicated with cataracts exist.