Jian-Huan Chen

Interactive Effects of ATOH7 and RFTN1 in Association with Adult-Onset Primary Open-Angle Glaucoma

PURPOSE Genome-wide association studies have shown association of the atonal homolog 7 (ATOH7) and raftlin lipid raft linker 1 (RFTN1) genes with glaucoma-related optic disc parameters. ATOH7 and RFTN1 sequence variations were investigated in patients with primary open-angle glaucoma (POAG) and their relationships with vertical cup-to-disc ratio (VCDR) and central corneal thickness (CCT) were determined. METHODS In 289 unrelated controls and 142 patients with adult-onset POAG, including 117 with high-tension glaucoma (HTG) and 25 with normal-tension glaucoma (NTG), the single exon of ATOH7 was sequenced by direct sequencing. Additional single-nucleotide polymorphisms (SNP) at upstream ATOH7 (rs1900004 and rs3858145) and an RFTN1 SNP (rs690037) were genotyped. Quantitative trait and disease associations were analyzed by linear and logistic regression respectively, controlling for sex and age. RESULTS ATOH7 rs61854782 was associated with VCDR (P = 0.004) in controls and RFTN1 rs690037 was associated with CCT in combined POAG (HTG+NTG; P = 0.026). No coding mutation was detected in POAG, and no SNP was associated with POAG (P between 0.441 and 0.996). However, ATOH7 rs3858145 showed significant interaction with RFTN1 rs690037 in NTG and combined POAG (P = 0.026 and 0.013 respectively). ATOH7 rs3858145 GG combined with RFTN1 rs690037 TT conferred risk for glaucoma in HTG, NTG, and combined POAG (odds ratio = 2.11, 8.44, and 2.69, respectively). CONCLUSIONS Coding mutations of ATOH7 were unlikely to be involved in POAG. But combination of ATOH7 and RFTN1 SNPs increased risk to POAG, indicating their diversified effects in the complex genetics of glaucoma.

Association analysis of cigarette smoking with onset of primary open-angle glaucoma and glaucoma-related biometric parameters

BackgroundTo date, studies on the role played by cigarette smoking in primary open-angle glaucoma (POAG) remains controversial. The current study evaluated cigarette smoking as a risk factor of POAG and its relationships with vertical cup-to-disc ratio (VCDR), central corneal thickness (CCT) and intraocular pressure (IOP) in a Chinese cohort.MethodsIn a total of 248 unrelated individuals including 30 juvenile-onset POAG (JOAG), 92 adult-onset POAG (AOAG) and 126 sex-matched senile cataract controls, underwent comprehensive ophthalmic examination. Their smoking was obtained and documented by questionnaire. Association of cigarette smoking with POAG was performed using logistic regression controlled for age and sex. Effects of cigarette smoking on VCDR, IOP and CCT were analyzed with multiple linear regression.ResultsIn either JOAG or AOAG, no association of cigarette smoking was found with disease onset (P = 0.692 and 0.925 respectively). In controls and JOAG, no significant effects of smoking were found on VCDR, IOP or CCT (all P > 0.05). Smoking was found to be correlated with decreased CCT in AOAG and combined POAG (JOAG + AOAG) (P = 0.009 and 0.003), but no association with VCDR or IOP was observed (P > 0.05).ConclusionsAlthough cigarette smoking was not found to be risk factor for onset of POAG, it was correlated with CCT in AOAG, and thus might still play a role in the disease course, especially for AOAG.

Association of HLA-DR4/ HLA-DRB1*04 with Vogt-Koyanagi-Harada disease: A Systematic Review and Meta-analysis

Human leukocyte antigen (HLA)-DR4/HLA-DRB1*04 has been reported to be a risk factor for Vogt-Koyanagi-Harada disease (VKH) with various strength of association. Its sub-alleles were also found to be associated with VKH. However the results were inconsistent. In this study, we systematically searched the related literature, pooled the odds ratios (ORs) and 95% confidence interval (CI) of association of HLA-DR4/HLA-DRB1*04 or its sub-alleles with VKH from individual studies, and explored the potential source of heterogeneity. A total of 1853 VKH patients and 4164 controls from 21 articles were included in this meta-analysis. The pooled OR of association of HLA-DR4/HLA-DRB1*04 and VKH was 8.42 (95% CI: 5.69–12.45). There were significant heterogeneity (I2 = 71%). Subgroup analysis indicated that ethnicity was the source of heterogeneity (all I2 = 0, ORs ranged from 2.09–13.69 in subgroups). The sub-alleles, HLA-DRB1*0404 (OR = 2.57), 0405 (OR = 10.31) and 0410 (OR = 6.52) increased the risk of VKH; 0401 (OR = 0.21) protected VKH; while other sub-alleles were not associated with VKH. Our meta-analysis confirmed the association between VKH and HLA-DR4/DRB1*04, found the strength of association is different in different ethnic groups, and identified HLA-DRB1*0404, 0405 and 0410 as risk sub-alleles while 0401 as protective sub-allele.

Association of Transcription Factor 4 (TCF4) and Protein Tyrosine Phosphatase, Receptor Type G (PTPRG) with Corneal Dystrophies in Southern Chinese

Abstract Fuchs’ endothelial dystrophy is a common type of posterior CD characterized by the development of gutta in the Descemet membrane. Recently, TCF4 was considered as a major risk gene for European FED cases. However, another recent report has shown that rs613872 was not associated with Singaporean Chinese FEDs. Recent reports indicate the genotypic heterogeneity of FEDs in different ethnic populations. It is thus essential to understand whether these genes affect the occurrence of FEDs and non-Fuchs’ CD in the local population. In the present study, we screened several reported SNPs (rs2286812, rs17595731 and rs613827 in TCF4; rs7640737 and rs2292245 in PTPRG) in FED and non-Fuchs’ patients with corneal dystrophies of southern Chinese.

Rapid and cost-effective molecular diagnosis using exome sequencing of one proband with autosomal dominant congenital cataract

PurposeDue to high genetic heterogeneity, to exclude known mutations and map novel mutations in autosomal dominant congenital cataract (ADCC) using conventional candidate gene screening requires laborious laboratory work. We attempted to use a cost-effective exome sequencing strategy to identify disease-causing mutations in an ADCC pedigree.MethodsAn ADCC pedigree affected by nuclear cataract and 200 unrelated senile cataract controls were recruited and given comprehensive ophthalmic examination. Whole exome of the proband of the family was captured by the Illumina TruSeq Exome Enrichment Kit, followed by sequencing using Illumina HiSeq 2000 sequencer. Validation was performed by direct sequencing.ResultsThe whole exome, including all exons of known ADCC disease-causing genes, was screened for possible disease-causing mutations. A recurrent missense mutation c.773C>T (p.S258F) in exon 2 of the gap junction protein alpha 8 gene (GJA8) was identified in the proband with nuclear cataract. The result was confirmed by direct sequencing. The mutation showed complete co-segregation with the disease phenotype in the family but was not observed in unrelated unaffected controls.ConclusionBy successfully sequencing whole exome of only one proband and identifying a GJA8 mutation in one ADCC pedigree, the current study demonstrated that exome sequencing could serve as a rapid, robust, and cost-effective approach in clinical diagnosis and disease-causing gene discovery for ADCC.

Mutations of RagA GTPase in mTORC1 Pathway Are Associated with Autosomal Dominant Cataracts.

Cataracts are a significant public health problem with no proven methods for prevention. Discovery of novel disease mechanisms to delineate new therapeutic targets is of importance in cataract prevention and therapy. Herein, we report that mutations in the RagA GTPase (RRAGA), a key regulator of the mechanistic rapamycin complex 1 (mTORC1), are associated with autosomal dominant cataracts. We performed whole exome sequencing in a family with autosomal dominant juvenile-onset cataracts, and identified a novel p.Leu60Arg mutation in RRAGA that co-segregated with the disease, after filtering against the dbSNP database, and at least 123,000 control chromosomes from public and in-house exome databases. In a follow-up direct screening of RRAGA in another 22 families and 142 unrelated patients with congenital or juvenile-onset cataracts, RRAGA was found to be mutated in two unrelated patients (p.Leu60Arg and c.-16G>A respectively). Functional studies in human lens epithelial cells revealed that the RRAGA mutations exerted deleterious effects on mTORC1 signaling, including increased relocation of RRAGA to the lysosomes, up-regulated mTORC1 phosphorylation, down-regulated autophagy, altered cell growth or compromised promoter activity. These data indicate that the RRAGA mutations, associated with autosomal dominant cataracts, play a role in the disease by acting through disruption of mTORC1 signaling.

Multimodal retinal imaging in a Chinese kindred with familial amyloid polyneuropathy secondary to transthyretin Ile107Met mutation.

ObjectiveTo investigate the ocular phenotype and gene mutation of a Chinese pedigree with familial amyloid polyneuropathy (FAP) and vitreous amyloidosis.MethodsA Chinese pedigree with familial amyloid polyneuropathy and vitreous amyloidosis was recruited. Combined phacoemulsification, vitrectomy and intraocular lens implantation were performed on the right eye of the index patient. Ophthalmic investigations were performed before and after surgery. The DNA from the pedigree was sequenced for the transthyretin (TTR) gene.ResultsAfter vitrectomy, the best-corrected visual acuity of the patient improved from counting finger to 20/20. Red-free confocal ophthalmoscopy demonstrated perifoveal ring and several perivessel white sheaths. Optical coherence tomography (OCT) revealed cotton wool like reflections on the vitreoretinal interface. Electroretinogram and autofluorescence was normal. Amyloid was present in the vitreous specimen. A substitution of T to G at nucleotide 381 in exon 4 of TTR DNA (Ile107Met) was found. This mutation co-segregated with phenotype in the pedigree and was not detected in 200 controls.ConclusionsTTR Ile107Met mutation is associated with vitreous amyloidosis and FAP. OCT and red-free imaging are helpful in identifying amyloid deposits in the retina.