OBJECTIVE: The CYP4V2 gene of two pedigrees affected with Bietti crystalline corneoretinal dystrophy was analyzed to indentify the cause of the disease and provide a basis for clinical diagnosis. METHODS: The probands were subjected to next generation sequencing (NGS). Suspected variants were verified by Sanger sequencing. Pathogenicity of the variants were searched through relevant databases and PubMed by following the ACMG guidelines. RESULTS: A homozygous variant in the CYP4V2 gene c. (802-8) _810delTCATACAGGTCATCGCTinsGC was detected in proband from pedigree 1, parents did not detect; CYP4V2 genes c. (802-8)_810delTCATACAGGTCATCGCTinsGC and c. 958 C>T (p.Arg320X) compound heterozygous variants existed in the proband of pedigree 2,both parents were variant carriers. The results of Sanger sequencing showed that the variant of CYP4V2 gene in the two families was consistent with the NGS sequencing. The c. (802-8)_810delTCATACAGGTCATCGCTinsGC of CYP4V2 gene was splicing variant, and both splicing variant and nonsense variant could produce truncated nonfunctional protein products. Based on standards and guidelines by American College of Medical Genetics and Genomics, the CYP4V2 genes c. (802-8)_810del TCATACAGGTCATCGCTinsGC and c. 958 C>T (p.Arg320X) were predicted to be pathogenic variants (PVS1+PS1+PM2+PM3). CONCLUSION The homozygous variant c. (802-8) _810delTCATACAGGTCATCGCTinsGC and the complex heterozygous variants c. (802-8) _810delTCATACAGGTCATCGCTinsGC and c.958C>T (p.Arg320X) in CYP4V2 gene are the cause of the disease in the probands of two pedigrees , respectively.
Corneal Dystrophies, Hereditary/pathology* ; Cytochrome P450 Family 4/genetics* ; Genetic Variation ; Humans ; Mutation ; Pedigree ; Phenotype ; Retinal Diseases/pathology*

OBJECTIVETo analyze the clinical features and TGFBI gene mutation in a Chinese family affected with Reis-Bucklers corneal dystrophy.

METHODSGenomic DNA was extracted from 53 members including 9 patients from the family. The 17 exons and splice region of introns of the TGFBI gene were amplified by PCR and directly sequenced. All family members were subjected to ophthalmologic examination.

RESULTSA heterozygous mutation (R124L) was found in exon 4 of the TGFBI gene among all patients from the family. The same mutation was not found among unaffected family members. The inheritance pattern of the family was identified as autosomal dominant, and the Reis-Bucklers corneal dystrophy in the family was diagnosed as the geographic type.

CONCLUSIONThe R124L mutation of the TGFBI gene probably underlies the pathogenesis of Reis-Bucklers corneal dystrophy in this Chinese family. Molecular genetic approach is useful for the proper diagnosis of this type of corneal dystrophy.

Corneal Dystrophies, Hereditary ; etiology ; genetics ; Female ; Humans ; Male ; Mutation ; Sequence Analysis, DNA ; Transforming Growth Factor beta1 ; genetics

No abstract available.
Asian Continental Ancestry Group ; Corneal Dystrophies, Hereditary/diagnosis/*genetics ; Cytochrome P450 Family 4/*genetics ; DNA Mutational Analysis ; Fluorescein Angiography ; Humans ; Male ; Middle Aged ; *Mutation ; Polymerase Chain Reaction ; Republic of Korea ; Retinal Diseases/diagnosis/*genetics ; Retinal Pigment Epithelium/pathology ; Tomography, Optical Coherence ; Visual Acuity

BACKGROUND: Mutations in the transforming growth factor beta-induced gene (TGFBI) are major causes of genetic corneal dystrophies (CDs), which can be grouped into TGFBI CDs. Although a few studies have reported the clinical and genetic features of Korean patients with TGFBI CD, no data are available regarding the frequency and spectrum of TGFBI mutations in a consecutive series of Korean patients with clinically diagnosed CDs. METHODS: Patients with any type of CD, who underwent both ophthalmologic examination and TGFBI gene analysis by Sanger sequencing at a tertiary care hospital in Seoul, Korea from 2006 to 2013, were enrolled in this study. RESULTS: Among a total of 89 patients, 77 (86.5%) were diagnosed as having clinical TGFBI CD. Seventy-three out of 74 patients (98.6%) with granular CD type 2 (GCD2), had the p.R124H mutation. Of particular note, one patient with rapidly progressive CD had the p.R124H mutation as well as a novel nonsense variant with unknown clinical significance (p.A179*). In three patients with lattice CD type 1 (LCD1), one known mutation (p.R124C) and two novel variants (p.L569Q and p.T621P) in the TGFBI gene were identified. CONCLUSIONS: This study provides epidemiological insight into CDs in a Korean population and reaffirms that GCD2 is the most common TGFBI CD phenotype and that p.R124H is the only mutation identified in patients with GCD2. In addition, we broaden the spectrum of TGFBI mutations by identifying two novel missense variants in patients with LCD1.
Adolescent ; Adult ; Aged ; Asian Continental Ancestry Group/*genetics ; Corneal Dystrophies, Hereditary/diagnosis/*genetics ; DNA Mutational Analysis ; Female ; Humans ; Male ; Middle Aged ; Phenotype ; Polymorphism, Single Nucleotide ; Republic of Korea ; Retrospective Studies ; Transforming Growth Factor beta1/*genetics ; Young Adult

An 87-year-old woman visited our clinic for a scheduled cataract surgery. At the time of preoperative evaluation, slit lamp examination showed lattice-shaped and granular deposits with asymmetrical patterns in the stroma of both corneas. Genomic DNA samples of the patient, amplified by polymerase chain reaction, showed a single nucleotide substitution, c. 1580T>G (p.L527R), in the transforming growth factor-beta-induced TGFBI gene. We also found two additional SNP mutations, c.1620T>C (p.F540F) and c.1678+23G>A, along with the well-known L527R mutation. This is the first report of lattice corneal dystrophy type IV with an L527R mutation outside of Japan, and could challenge the idea that L527R is caused by a mutation from a single Japanese ancestor.
Aged, 80 and over ; Corneal Dystrophies, Hereditary/diagnosis/*genetics/metabolism ; DNA/*genetics ; DNA Mutational Analysis ; Extracellular Matrix Proteins/*genetics/metabolism ; Female ; Humans ; *Mutation ; Pedigree ; Polymerase Chain Reaction ; Transforming Growth Factor beta/*genetics/metabolism

An 87-year-old woman visited our clinic for a scheduled cataract surgery. At the time of preoperative evaluation, slit lamp examination showed lattice-shaped and granular deposits with asymmetrical patterns in the stroma of both corneas. Genomic DNA samples of the patient, amplified by polymerase chain reaction, showed a single nucleotide substitution, c. 1580T>G (p.L527R), in the transforming growth factor-beta-induced TGFBI gene. We also found two additional SNP mutations, c.1620T>C (p.F540F) and c.1678+23G>A, along with the well-known L527R mutation. This is the first report of lattice corneal dystrophy type IV with an L527R mutation outside of Japan, and could challenge the idea that L527R is caused by a mutation from a single Japanese ancestor.
Aged, 80 and over ; Corneal Dystrophies, Hereditary/diagnosis/*genetics/metabolism ; DNA/*genetics ; DNA Mutational Analysis ; Extracellular Matrix Proteins/*genetics/metabolism ; Female ; Humans ; *Mutation ; Pedigree ; Polymerase Chain Reaction ; Transforming Growth Factor beta/*genetics/metabolism

To report a novel mutation within the CHST6 gene, as well as describe light and electron microscopic features of a case of macular corneal dystrophy. A 59-year old woman with macular corneal dystrophy in both eyes who had decreased visual acuity underwent penetrating keratoplasty. Further studies including light and electron microscopy, as well as DNA analysis were performed. Light microscopy of the cornea revealed glycosaminoglycan deposits in the keratocytes and endothelial cells, as well as extracellularly within the stroma. All samples stained positively with alcian blue, colloidal iron, and periodic acid-Schiff. Electron microscopy showed keratocytes distended by membrane-bound intracytoplasmic vacuoles containing electron-dense fibrillogranular material. These vacuoles were present in the endothelial cells and between stromal lamellae. Some of the vacuoles contained dense osmophilic whorls. A novel homozygous mutation (c.613 C>T [p.Arg205Trp]) was identified within the whole coding region of CHST6. A novel CHST6 mutation was detected in a Korean macular corneal dystrophy patient.
Corneal Dystrophies, Hereditary/diagnosis/*genetics/metabolism ; Corneal Keratocytes/ultrastructure ; DNA/*genetics ; DNA Mutational Analysis ; Female ; Humans ; Microscopy, Electron ; Middle Aged ; *Mutation, Missense ; Pedigree ; Polymerase Chain Reaction ; Republic of Korea ; Sulfotransferases/*genetics/metabolism

A 43-year-old man developed decreased vision in the right eye that had persisted for seven years. Under slit lamp examination, corneal clouding was noted with normal endothelium and ocular structure. From the clinical evidence, we suspected that the patient had congenital hereditary stromal dystrophy (CHSD). He and his family underwent a genetic analysis. Penetrating keratoplasty was conducted, and the corneal button was investigated for histopathologic confirmation via both light and electron microscopy. The histopathologic results revealed mildly loosened stromal structures, which exhibited an almost normal arrangement and differed slightly from the previous findings of CHSD cases. With regard to the genetic aspects, the patient and his mother harbored a novel point mutation of the decorin gene. This genetic mutation is also distinct from previously described deletion mutations of the decorin gene. This case involved delayed penetration of mild clinical symptoms with the histological feature of a loosened fiber arrangement in the corneal stroma. We concluded that this condition was a mild form of CHSD. However, from another perspective, this case could be considered as "decorin gene-associated corneal dystrophy," which is distinct from CHSD. Further evaluation will be required for appropriate clinical, histopathologic and genetic approaches for such cases.
Adult ; Corneal Dystrophies, Hereditary/diagnosis/*genetics ; Decorin/*genetics ; Humans ; Male ; Microscopy, Electron ; Pedigree ; *Point Mutation ; Republic of Korea

Granular corneal dystrophy, type II (CGD2; Avellino corneal dystrophy) is the most common corneal dystrophy among Koreans, but its pathophysiology is still poorly understood. Many reports showed that even though the causative mutation is the same TGFBI R124H mutation, there are severe and mild phenotypes of the corneal dystrophy. We also observed the phenotype differences in our samples. For this reason, we focused our effort on the identification of unknown genetic factor related to phenotype variation. A total 551 individuals from 59 families were genotyped with SNP chip and used in genome-wide linkage analysis. From single-point linkage analyses, we confirmed the known 5q31 region for TGFBI gene, and selected novel nine candidate loci for CGD2. In simulation analysis, the only 3q26.3 region including neuroligin 1 gene (NLGN1) was supported by empirical statistic significance. To investigate the effect of genetic heterogeneity in linkage analysis, we classified CGD2 families into two subgroups. Although we could not find a significant evidence for correlation between the 3q26.3 region and CGD2 phenotypes, this first genome-wide analysis with CGD2 families in Korea has a very important value for offering insights in genetics of CGD2. In addition, the co-segregating loci with CGD2 including 3q26.3 would be a good target for further study to understand the pathophysiology of CGD2.
Cell Adhesion Molecules, Neuronal/genetics ; Chromosomes, Human, Pair 3/*genetics ; Chromosomes, Human, Pair 5/*genetics ; Computer Simulation ; Corneal Dystrophies, Hereditary/*genetics ; Female ; Genetic Linkage ; *Genetic Loci ; *Genome-Wide Association Study ; Genotype ; Humans ; Male ; Models, Genetic ; Polymorphism, Single Nucleotide ; Transforming Growth Factor beta1/genetics

OBJECTIVETo investigate the transforming growth factor beta induced (TGFBI; BIGH3) gene mutation and founder effect of two large Chinese families clinically diagnosed as Thiel-Behnke corneal dystrophy.

METHODSFifteen members including 13 affected and 2 healthy in family A, 14 members including 6 affected and 8 healthy in family B, as well as 20 other unrelated healthy individuals were tested for TGFBI gene mutation. Haplotype analysis and clinical examination were also carried out in the two families.

RESULTSIn exon 12 of the TGFBI gene, 1664G to A change was detected in all the patients, which leads to an amino acid replacement of arginine with glutamine (p.Arg555Gln). Members of the two families share some similar haplotypes.

CONCLUSIONGenetic analysis is helpful in the diagnosis of corneal dystrophy. The two families may come from a same ancestor.

Adolescent ; Adult ; Aged ; Asian Continental Ancestry Group ; genetics ; Base Sequence ; Child ; Corneal Dystrophies, Hereditary ; diagnosis ; genetics ; Exons ; Extracellular Matrix Proteins ; genetics ; Female ; Founder Effect ; Humans ; Male ; Middle Aged ; Molecular Sequence Data ; Pedigree ; Point Mutation ; Transforming Growth Factor beta ; genetics ; Young Adult