Effect of prisms on visual acuity,contrast sensitivity and nystagmus in patients with albinism

AIM:To investigate the effect of using base-out prisms on nystagmus,visual acuity and contrast sensitivity in patients with albinism.METHODS:In this interventional study,patients with albinism who had nystagmus were enrolled.A comprehensive eye exam was conducted,which included refraction,assessment of far and near vision acuity,and contrast sensitivity measurements.To check for the nystagmus,a videonystagmography was used.The tests were carried out in three modes:without any correction,with optical correction,and with correction using base-out prisms in three different powers,including 4,6,and 8 prism diopters.RESULTS:Totally 23 patients with average age of 28.65±12.13 were examined.It was found that the use of optical correction and optical correction with prisms resulted in a statistically significant improvement in both far(at least:P<0.006)and near visual acuity(at least:P<0.001 except for prism 8;P<0.02).In addition,contrast sensitivity significantly improved at all low and medium frequencies except for correction with prism 8 in frequency 1.5(at least:P<0.01 except for prism 4,frequency 6;P=0.04).no significant improvement was observed in the evaluation of nystagmus characteristics.CONCLUSION:Optical correction with a prism can improve visual acuity and some spatial frequencies,but failed to improve nystagmus parameters.

The tyrosinase gene family and albinism in fish

Tyrosinase exists universally in organisms and is a characteristic enzyme of melanocytes. Tyrosinase family genes in vertebrates consist of 3 related members; tyrosinase （TYR, Tyr）, tyro sinase-related protein-1 （TRP-1, Tyrp 1）, and tyro sinase-related protein-2 （TRP-2, Tyrp2, Dct）. These proteins catalyze melanin biosynthesis in pigment cells and play important roles in determining vertebrate coloration. Transcription of the TYR and TRP genes is useful for studying neural crest and optic vesicle cell migration and differentiation during emblyogenesis and important in pigment rescue in fish. In this paper, the structure of gene and protein molecular evolution, function and roles of the TYR family in fish were reviewed.

QTL Detection for Albinism-Related Loci in Chinese Tongue Sole(Cynoglossus semilaevis)

The Chinese tongue sole(Cynoglossus semilaevis) is widely cultured in the coastal region of East Asia and has excellent economic value. However, the high albino rate of the breeding population has caused a significant loss to the aquaculture industry. To study the molecular mechanism of albinism, the present study used an albino Chinese tongue sole family to construct three simple sequence repeat(SSR) linkage groups, and draft a preliminary linkage map related to albinism. After albinism-related loci mapping, 18 albinism-related loci were detected under two models(containing 2407 genes) compared to the Chinese tongue sole genome. One of these loci, the tyrosinase related protein(tyrp2), which has been reported previously as an important gene regulating both eumelanin and phaeomelanin levels, was indicated to be the possible cause of albinism. Thirty-five Gene Ontology(GO) terms and 14 Kyoto Encyclopedia of Genes and Genome pathways were annotated via bioinformatic analyses. One GO term with protein tyrosine kinase activity, which contained 10 genes, was previously suggested to affect fish albinism. These results establish a foundation for further in-depth study of albinism in Chinese tongue sole.

Homozygosity mapping of a consanguineous Pakistani family affected with oculocutaneous albinism to Tyrosinase gene

Dear Sir,Iam Haiba Kaul,from the Department of Biochemistry,University of Health Sciences,Lahore,Pakistan.I write to present a study of oculocutaneous albinism（OCA）in consanguineous Pakistani families.OCA is a genetic defect of melanin biosynthesis that mainly affects eyes,skin and hair.

Comment on homozygosity mapping of a consanguineous Pakistani family affected with oculocutaneous albinism to Tyrosinase gene

Dear Editor,I have carefully read the article entitled ＂Homozygosity mapping of a consanguineous Pakistani family affected with oculocutaneous albinism to Tyrosinase gene＂,published by Shakil et al in 2016 and found it very interesting for the scientific community.

The Detection of Partial Albinism at Three Species of Bats (Mammalia: Chiroptera) in European Part of Russia

The first time for the territory of European Russia describes the cases of catching bats with signs of albinism. This article describes the detection of three species of bats with partial albinism in European part of Russia. There are four animal units of Eptesicus serotinus turcomanus that are stored in Penza State University. They were procured in Astrahan region in 1992 and in 1996. One more animal was found in Volgograd region in 2004. All these animals have white spots of different size and shape on their abdominal part of body. In 2012 it was caught a young female of Pipistrellus nathusii in Samarskaya Luka (Samara region) and in 2013 the scientists found a mature female of Myotis mystacinus. Both animals had a light-colored fur, red eyes and with almost white ears. Moreover, they had pale-pink noses and extremities.

Correlation of Macular Thickness, Multifocal ERG with Visual Acuity in Oculocutaneous Albinism (OCA)

Background and Aim: Ocular albinism is known to have nystagmus and foveal hypoplasia. A study was done to evaluate the correlation of visual acuity with macular thickness (MT) and mf ERG. Materials and Methods: A total of 20 eyes (10 patients) with OCA were selected. Macular thickness was evaluated with optical coherence tomography and mf ERG was done in all the patients. Results: Mean age was 16.1 ± 7.3 years. The patients were divided into three groups based on their visual acuity > 6/12 (group A), 6/18 - 6/24 (group B), 6/36 or less (group C). Mean MT in patients with visual acuity in group A, B and C was 194.8 ± 26.7, 220 ± 12.3 and 243.5 ± 17.3 microns respectively. The amplitudes of first positive wave (P1) and first negative wave (N1) for the central ring in mf ERG in patients of group A, B and C was 1.1 ± 0.5 (P1), 0.7 ± 0.2 (N1), 0.6 ± 0.5 (P1), 0.3 ± 0.2 (N1), 0.7 ± 0.2 (P1), 0.3 ± 0.1 (N1) microvolts respectively. The vision correlated well with the macular thickness. The mf ERG potentials (P1 and N1) do not correlate with the visual acuity. Conclusion: We believe that the visual acuity in albinotic patients is affected by the macular thickness but the electric potentials do not depend on the visual acuity.

Studies Shed Light on the Albinism Gene of Rhesus Monkey

A recent study by researchers at the Kunming Institute of Zoology (KIZ) of the Chinese Academy of Sciences (CAS) identifies the albinism gene of rhesus monkeys using the method of molecular technology, and suggests the age of the albinism gene in rhesus monkeys should be roughly 800,000 years. The general albinism

Genetic analyses of Chinese patients with digenic oculocutaneous albinism

Background Oculocutaneous albinism （OCA） is a heterogeneous and autosomal recessive disorder in all populations worldwide. The mutational spectra of OCA are population-specific. Some OCA patients carry mutations from different OCA genes. In this study, we investigated the frequency of digenic mutations in Chinese OCA patients. Methods Genomic DNAs were extracted from the blood samples of 184 clinically diagnosed OCA patients and 120 unaffected subjects. The amplified DNA segments of the exons and exon-intron boundaries were screened for mutations of TYR, OCA2, TYRP1, SLC45A2, and HPS1 by direct sequencing. To exclude the previously unidentified alleles from polymorphisms, samples from 120 unaffected controls were sequenced for the same regions of variations. Results In all 184 patients, 134 had two pathologic mutations on one locus. Eleven cases had no apparent pathologic mutations in any of the genes studied. Among the remaining 39 patients who had only one pathologic mutation, five patients （2.7% in total） were found to carry the mutational alleles on a second locus in TYR, OCA2 or SLC45A2. Of the five digenic OCA patients, four patients were clinically diagnosed as OCA2 and one patient as OCAI. A previous unidentified allele p.G188D in SLC45A2 was identified, which was not present in the 120 unaffected controls. Conclusions The identification of the digenic OCA patients suggests the synergistic roles among TYR, OCA2 and SLC45A2 during melanin biosynthesis, which may cause OCA under digenic mutations. This information will be useful for gene diagnosis and genetic counseling of OCA in China.

A novel missense mutation of the TYR gene in a pedigree with oculocutaneous albinism type 1 from China

Background The mutation of the tyrosinase （TYR） gene results in oculocutaneous albinism type 1 （OCA1）, an autosomal recessive genetic disorder. OCA1 is the most common type of OCA in the Chinese population. Hence, the TYR gene was tested in this study. We also delineated the genetic analysis of OCA1 in a Chinese family. Methods Genomic DNA was isolated from the blood leukocytes of a proband and his family. Mutational analysis at the TYR locus by DNA sequencing was used to screen five exons, including the intron/exon junctions. A pedigree chart was drawn and the fundus of the eyes of the proband was also examined. Results A novel missense mutation p.1151S on exon 1, and homozygous TYR mutant alleles were identified in the proband. None of the mutants was identified among the 100 normal control subjects. Genetic analysis of the proband＇s wife showed normal alleles in the TYR gene. Thus, the fetus was predicated a carrier of OCA1 with a normal appearance. Conclusion This study provided new information about a novel mutation, p.1151S, in the TYR gene in a Chinese family with OCAI. Further investigation of the proband would be helpful to determine the effects of this mutation on TYR activity.

Prenatal Genotyping of Four Common Oculocutaneous Albinism Genes in 51 Chinese Families

Oculocutaneous albinism（OCA） is an autosomal recessive disorder characterized by hypopigmentation in eyes,hair and skin,accompanied with vision loss.Currently,six genes have been identified as causative genes for non-syndromic OCA（OCA-1w4,6,7）,and ten genes for syndromic OCA（HPS-1e9,CHS-1）.Genetic counseling of 51 Chinese OCA families（39 OCA-1 with mutations in the TYR gene,6 OCA-2 with mutations in the OCA2 gene,4 OCA-4 with mutations in the SLC45A2 gene,1 HPS-1（Hermanskye Pudlak syndrome-1） with mutation in the HPS1 gene,and 1 mixed OCA-1 and OCA-4） led us to perform the prenatal genetic testing of OCA using amniotic fluid cells through the implementation of our optimized strategy.In our cohort,eleven previously unidentified alleles（PUAs）（5 in TYR,2 in OCA2,and 4 in SLC45A2） were found.Three missense PUAs（p.C112 R,p.H363 R and p.G379 V of TYR） and one in-frame deletional PUA（p.S222 del of SLC24A5） led to fetuses with OCA when co-inherited with other disease causative alleles.Three PUAs（p.P152 H and p.W272 X of TYR,p.A486 T of SLC24A5） identified in the OCA probands did not co-transmit with known pathological alleles and thus gave rise to unaffected fetuses.Four PUAs（p.Q83 X and p.A658 T of TYR,p.G161 R and p.G366 R of SLC24A5） did not transmit to the unaffected fetuses.In addition,the in vitro transfection assays showed that the p.S192 Y variant of TYR produced less pigment compared to the wild-type allele.A fetus with a digenic carrier of OCA-1 and OCA-4 was unaffected.In combination with functional assays,the family inheritance pattern is useful for the evaluation of pathogenicity of PUAs and genetic counseling of OCA.

Application of multiplex ligation-dependent probe amplification in the genetic testing of oculocutaneous albinism

To the Editor: Oculocutaneous albinism (OCA) is an autosomal recessive disorder caused by a group of mutations related to the regulation of melanin synthesis and melanosome biogenesis. The prevalence of OCA worldwide is approximately 1 in 17,000.[1] Other than symptomatic treatment, there is no effective treatment for albinism. Due to the variability in clinical phenotypes, it is difficult to classify sub-types simply by clinical features;therefore, molecular and genetic analyses are the most reliable methods for confirming diagnosis, carrier screening, and pre-natal diagnosis.

Oculocutaneous Albinism with Squamous Cell Carcinoma, Bowen’s Disease and Actinic Keratosis: A Case Report

IntroductionOculocutaneous albinism (OCA) is an autosomal recessive disorder characterized by defects in melanin synthesis that affect the skin,eyes,ears,and hair to varying degrees.Because of the melanin deficiency,albino patients are at high risk for sun-induced skin cancers.Herein,we report a rare case of an OCA type 4 combined with a progressive carcinogenesis for precancerous (actinic keratosis,AK),in situ (Bowen's disease),and invasive status of squamous cell carcinoma (SCC).

Chronic ulcerative gastroduodenitis as a first gastrointestinal manifestation of Hermansky-Pudlak syndrome in a 10-year-old child

A 10-year-old Chinese boy who had a history of congenital thrombocytopathy presented with severe iron deficiency anemia secondary to chronic gastric inflammation and duodenal ulcerations. Subtle oculocutaneous albinism led to the finding of diminished dense bodies in the platelets under electron microscopy, hence the diagnosis of Hermansky-Pudlak syndrome (HPS). Biopsies from the stomach and duodenum revealed a lymphocytic infiltration in the submucosa, but H pylori infection was absent. The gastroduodenitis responded to the treatment with omeprazole while iron deficiency anemia was corrected by oral iron therapy. HPS is a rare cause of congenital bleeding disorder with multisystemic manifestations. Upper gastrointestinal involvement is rare and should be distinguished from a mere manifestation of the bleeding diathesis.

Identification of a Homozygous Missense Mutation in the TYR Gene in a Chinese Family with OCA1

Oculocutaneous albinism (OCA)is an autosomal recessive pigmentation abnormality,characterized by variable hair,skin,and ocular hypopigmentation.OCA1 is the most frequent subtype of OCA,caused by mutations in the tyrosinase gene (TYR). In this study,we investigated the genetic mutation of a Chinese family with a female OCA patient who came for genetic counseling before pregnancy.Complete physical examination was performed,and DNA from blood samples was collected from the family members.Mutations of TYR,OCA2,and SLC45A2 genes were examined in the proband, and verified in her parents by Sanger sequencing.Large deletion or duplication of TYR and OCA2 genes was detected by multiplex ligation-dependent probe amplification (MLPA).A homozygous TYR c.307T>C (p.Cys103Arg)missense mutation was identified in the proband,and both parents were heterozygous carriers.No large deletion or duplication was found in the proband.This mutation was absent in 1000G,ExAC,or HGMD database,and multiple lines of in silico tools supported a deleterious effect.These results suggest that TYR c.307T>C mutation might be responsible for OCA1,and our study further expands the mutation spectrum of OCA1 in the Chinese population.

Comparative analysis of transcriptomes from albino and control sea cucumbers, Apostichopus japonicus

The sea cucumberApostichopus japonicus is an important economic species in China. Its dorsal body wall color is commonly tawny, whereas its ventral surface is fawn. Albino sea cucumbers are rarely observed. In order to profile gene expression and screen albinism-related genes, we compared the transcriptome of albino samples with a control by 454 cDNA sequencing. We found that 6 539 identified genes on the basis of sequence similarity to known genes were expressed in the albino A. japonicus. The gene ontology analysis indicated that the transcription of genes associated with the terms of biological regulation and pigmenta-tion was non-abundant in the albino library compared to the control. Based on an analysis using the Kyoto Encyclopedia of Genes and Genomics （KEGG） database, we identified 14 important genes that were in-volved in major intercellular signaling pathways related to melanin synthesis, such as tyrosine metabolism, the mitogen-activated protein kinase （MAPK） pathway, and melanogenesis. The expressions of fibroblast growth factor receptor 4 （FGFR4）, protein kinase C （PKC）, protein kinase A （PKA）, and Ras genes were sig-nificantly down-regulated in the albino transcriptome compared with the control, while the expressions of homogentisate 1, 2-dioxygenase gene （HGO）, cAMP-responsive element binding protein （CREB）, transcrip-tion factor AP-1（c-jun）, and calmodulin （CaM） were significantly up-regulated （Fisher＇s exact test,p 〈 0.05）. These differentially expressed genes could be candidate genes for revealing the mechanism of albinism and investigating regulation of melanin synthesis inA. japonicus.

Differential Effects of Cold and Heat Shock on Embryogenic Induction and Green Plant Regeneration from Wheat (Triticum aestivum L.) Microspores

Albinism is a common problem encountered by researchers in anther/microspore cultures of cereal crops. The present study investigates the effects of temperature variations on embryogenesis of wheat (Triticum aestivum L.) microspores. Following a cold (4°C - 13°C) vs. heat (33°C) shock to wheat tillers, microspores were isolated and cultured in a liquid medium to obtain embryoids. Data on embryogenic microspore%, embryoid yield, plant regeneration% and green plant% were collected and analyzed. Cold pretreatment of 4°C or 10°C for a period of 6 or 10 days were more effective than other cold temperature regimes in inducing microspore embryogenesis. The heat shock of 33°C yielded the highest numbers of embryogenic microspores and embryoids. The albino-prone genotypes produced significantly higher green plant% following optimal cold shock, as compared to the standard 33°C heat shock. Results from present study suggest that cold shock may be a desirable alternative for germplasm that produce lower green plant% using heat shock. Lowered incubation temperature during embryoid development did not result in higher green plant.

Ocular Manifestations Encountered in Albinos Living in Libreville: Epidemiological and Clinical Aspects

Introduction: Albinism is a rare hereditary genetic disorder, characterized by melanogenesis disorders associated to varying degrees of cutaneous, atrial and visual disorders. In Libreville, no data on the subject is available. Purpose: To describe the ocular manifestations found in albinos living in Libreville. Patients and methods: This was a cross-sectional and descriptive study that took place in Libreville during a year from and that concerned 43 albinos. The inclusion criteria were any albino with oculocutaneous albinism present in Libreville who has agreed to participate in the investigation. The variables studied were age, sex, visual acuity, ametropia, iris color, iris transillumination, strabismus, nystagmus, torticollis, amblyopia, optic disc, photophobia, foveal hypoplasia and retinal hypopigmentation. Data was collected and analyzed using Epi infoTM 7.2.0.1 CDC and?IBM&#174?SPSS&#174?V21 Statistic software. Results: The mean age was 21.2 ± 17 years with a (F/M) ratio of 0.53. Visual acuity by far without correction (AVLCSC) < 3/10 was found in 88.4% of cases. Astigmatism, two-tone iris and torticollis were found respectively in 52.7%, 51% and 26% of cases. Retinal hypopigmentation and foveal hypoplasia were noted in 65.1% and 86% of cases. Divergent strabismus was noted in 71.4% and small and pale papilla in 95.1% of cases. Photophobia, iris transillumination, nystagmus and amblyopia were noted in 100% of cases. Conclusion: The ocular manifestations encountered in our series are similar to those described in literatures.

Full-length transcriptome sequencing analysis reveals differential skin color regulation in snakeheads fish Channa argus

Albinism is a genetic disorder caused by a series of genetic abnormalities that result in a decrease in melanin.Golden yellow snakehead fish(GCAS)has been discovered while the Channa argus(CAS)breeding,but the genetic mechanism that causes its albinism is not known.Transcriptome sequencing and comparison of CAS and GCAS skin using Oxford Nanopore Technologies(ONT)technology to elucidate the molecular mechanisms of snakehead albinism.27.1 G clean reads and 26,198 full-length non-redundant sequences were generated via ONT sequencing.Overall,8079 new transcripts and 7231 genes were identified by comparing and analyzing redundant removed transcripts and known reference genome annotations.The results of DEGs analysis showed that a total of 59 transcripts were differentially expressed in the two groups,including 22 up-regulated transcripts and 37 down-regulated transcripts.Five causative genes associated with albinism have been identified,including TYR(Tyrosinase)and SOX10(SRY-box transcription factor 10)(tyrosinase synthesis and metabolism),S-100(S100 calcium binding protein A1)(melanin production),NLRC3(NLR family CARD domain containing 3)(disease immunity)are significantly down-regulated in GCAS,while RhoGEFs expression(melanin synthesis)is up-regulated.Protein interaction analysis revealed that GAPDH(Glyceraldehyde-3-phosphate dehydrogenase)is the top hub gene in the regulation of skin color in C.argus.In addition,the skin of snakehead fish is regulated by metabolic(GAPDH),immune[Tumor protein p53(TP53),C-X-C motif chemokine ligand 8(CXCL8),SRC proto-oncogene,non-receptor tyrosine kinase(SRC),CD274]and neural[Notch receptor 1(NOTCH1),C-X-C motif chemokine ligand 12(CXCL12)]related genes to achieve differences in skin color.These findings in understanding the process by which albinism in fish develops.

‘丘北辣椒’采后“白化病”病原鉴定及药剂毒力测定

0 引言辣椒(Capsicum annuum L.)是茄科辣椒属(Capsicum L.)的一种多年生草本植物,是我国仅次于大白菜的第二大蔬菜作物。‘丘北辣椒’是云南省特有的地方品种,因其色泽红亮、味道香辣淳厚而深受消费者喜爱,是云南文山第二大生物产业。近年来,‘丘北辣椒’出现了采收后晾晒干燥过程中辣椒果皮白化的现象,发生数量和程度逐年上升,种植面积由原来的五十余万亩减少到二十几万亩,极大影响了当地农户的经济收入。