Association of variants in GJA8 with familial acorea-microphthalmia-cataract syndrome

Congenital acorea is a rare disease with the absence of a pupil in the eye. To date, only one family and two isolated cases with congenital acorea have been reported. The gene associated with acorea has not been identified. In this study, we recruited a Chinese family acorea-microphthalmia-cataract syndrome. By analyzing the whole-exome sequencing (WES) data of this Chinese family, we revealed the association of a novel heterozygous variant, NM_005267.5:c.137G>A (p.G46E) in the gap junction protein alpha 8 (GJA8) gene encoding connexin 50 or CX50, with familial acorea-microphthalmia-cataract syndrome. Additionally, another variant, NM_005267.5:c.151G>A (p.D51N) in GJA8, was identified to co-segregate with this syndrome in an unrelated Japanese family. Ectopic expression of p.G46E and p.D51N mutant GJA8 genes in cultured cells caused protein mislocalization, suggesting that the p.G46E and p.D51N mutations in GJA8 impaired the function of the gap junction channels. These results established GJA8 as the first gene associated with familial acorea-microphthalmia-cataract syndrome.

Measuring macular pigment optical density using reflective images of confocal scanning laser system

PURPOSE

To develop a method to measure the macular pigment optical density (MPOD) using scanning laser ophthalmoscopic images in young adults and children.

STUDY DESIGN

Cross-sectional study.

METHODS

Blue light reflectance fundus images of 32 healthy subjects were used. A profile of the linear reflectance changes across the center of the fovea on a grayscale fundus image was generated. The ratio of the macula-to-periphery reflection was designated as the peak value of the MPOD (MPOD[FR]) based on established fundamentals. In the MPOD profile, the basal width of the pixels at MPOD < 0 (wMP) and width at one-half value of the MPOD[FR] (wMP0.5) were determined. The MOPD at eccentricity of 0.5° was measured by heterochromatic flicker photometry (MPOD[HFP]), and the correlation between the MPOD[FR] and MPOD[HFP] was evaluated.

RESULTS

The MPOD[FR] ranged from 0.17 to 0.73 with a mean of 0.40 ± 0.13. The wMP ranged from 88 to 173 pixels with a mean of 121.7 ± 24.2 pixels, and the wMP0.5 ranged from 38 to 83 pixels with a mean of 54.1 ± 10.3 pixels. A significant correlation was found between the MPOD[FR] and MPOD[HFP] (r = 0.41, P = 0.02).

CONCLUSIONS

This simplified method can provide accurate and reliable values of the MPOD comparable to heterochromatic flicker photometry. Obtaining the fundus images in this fast and easy way should be suitable for children thus enabling clinicians to determine the MPODs for children.

Optical coherence tomography findings of the peripheral retina in patients with congenital X-linked retinoschisis

Introduction

Congenital X-linked retinoschisis (XLRS) presents as macular retinoschisis/degeneration in almost all patients and as peripheral retinoschisis in half the patients. Although the optical coherence tomography (OCT) findings of macular retinoschisis have been well investigated, those of peripheral retinoschisis have rarely been reported. This study aimed to report the ultra-widefield OCT findings of the peripheral retina in patients with XLRS.

Methods

Medical records of 10 Japanese patients (19 eyes) with clinically and/or genetically diagnosed XLRS were retrospectively reviewed. Funduscopic, electroretinographic, and OCT findings were reviewed and evaluated. Some were also genetically evaluated for the RS1 gene.

Results

OCT of the macula revealed schises and/or cystoid changes in the inner nuclear layer (INL) and outer nuclear layer. In contrast, OCT of the peripheral retina revealed schises and/or cystoid changes in the INL in eight eyes (44%), and/or splitting in the ganglion cell layer (GCL) in 10 (56%) of the 18 eyes with clear OCT images. No schisis or cystoid changes were found in the peripheral OCT images of eight eyes (44%). A 16-year-old boy presented with retinal splitting of the GCL and INL of the inferior retina, although he had no ophthalmoscopic peripheral retinoschisis. Genetic examinations were performed on three patients, all of whom had reported missense mutations in the RS1 gene.

Conclusion

In XLRS, peripheral bullous retinoschisis results from GCL splitting in the retina. One of the 10 patients with XLRS showed intraretinal retinoschisis in the GCL in the inferior periphery, which was unremarkable on ophthalmoscopy (occult retinoschisis). Although both peripheral bullous retinoschisis and occult retinoschisis showed splitting/cystic changes in the GCL, further studies are needed to determine whether occult retinoschisis progresses to bullous retinoschisis.

Functional Characteristics of Diverse PAX6 Mutations Associated with Isolated Foveal Hypoplasia

The human fovea is a specialized pit structure in the central retina. Foveal hypoplasia is a condition where the foveal pit does not fully develop, and it is associated with poor vision. Autosomal dominant isolated foveal hypoplasia (FVH1) is a rare condition of foveal hypoplasia (FH) that lacks any other ocular manifestations. FVH1 is associated with hypomorphic mutations in the PAX6 gene that encodes a sequence-specific DNA-binding transcription factor for morphogenesis and evolution of the eye. We report our findings in 17 patients with PAX6 mutations associated with FVH1 or FH with aniridia and corneal opacities. Patients with three mutations, p.V78E, p.V83F and p.R128H, in the C-terminal subdomain of the paired domain (CTS) consistently have severe FH. Luciferase assays for a single reporter containing a representative PAX6 binding site indicated that the transcriptional activities of these mutations were significantly reduced, comparable to that of the truncation mutation of p.G65Rfs*5. Patients with p.P20S in the N-terminal subdomain of the paired domain, and a patient with p.N365K in the proline-serine-threonine-rich domain (PSTD) had mild FH. A patient with p.Q255L in the homeodomain had severe FH. The P20S and Q255L mutants did not affect the transcriptional activity. Mutant N365K has a retained DNA-binding activity but a reduced transcriptional activity, due to a low PSTD transactivation. These findings demonstrated that mutations associated with FVH1 underlie a functional divergence between DNA-binding ability and transcriptional activity. We conclude that a wide range of mutations in the PAX6 gene is not limited to the CST region and are responsible for FVH1.

EFFICACY OF INNER WALL RETINECTOMY FOR BULLOUS SCHISIS CAVITY HANGING OVER OR THREATENING THE MACULA IN PATIENTS WITH CONGENITAL X-LINKED RETINOSCHISIS

PURPOSE

To present the clinical characteristics, surgical outcomes, and surgical complications of patients with congenital X-linked retinoschisis who underwent vitrectomy for bullous schisis cavity hanging over or threatening the macula.

METHODS

Nine patients with congenital X-linked retinoschisis (12 eyes) who underwent vitrectomy at three tertiary hospitals and completed ≥3 years of postoperative follow-up were retrospectively investigated. Data were collected from patients' charts, including age at vitrectomy, surgical procedures, and postoperative complications.

RESULTS

The age at vitrectomy ranged 4 months to 103 months (median: 14 months). Inner wall retinectomy was performed during the initial vitrectomy in eight eyes. Among the eight eyes that initially underwent inner wall retinectomy, one (12.5%) required subsequent retinal surgery for postoperative complication. Furthermore, four eyes did not undergo initial inner wall retinectomy but required subsequent retinal surgeries for postoperative complications. Three of five eyes (60.0%) treated with silicone oil tamponade and two of seven eyes (28.6%) that were not treated with silicone oil tamponade during the initial vitrectomy required subsequent retinal surgeries for postoperative complications. All eyes maintained a clear central visual axis at the last examination.

CONCLUSION

Inner wall retinectomy seems beneficial in achieving a clear visual axis in eyes with bullous schisis cavity hanging over or threatening the macula in patients with congenital X-linked retinoschisis.

Late Vitreoretinal Complications of Regressed Retinopathy of Prematurity: Retinal Break, Vitreous Hemorrhage, and Retinal Detachment

PURPOSE

To investigate late vitreoretinal complications and visual outcomes in patients with regressed retinopathy of prematurity (ROP) with or without prior treatment.

DESIGN

International, multicenter, noncomparative retrospective case series.

PARTICIPANTS

We analyzed 264 eyes of 238 patients from 13 centers worldwide who developed vitreoretinal complications (retinal detachment [RD], vitreous hemorrhage [VH], or retinal break) ≥ 2 years after resolution of acute ROP.

METHODS

Each participant was assigned to 1 of 3 groups (the RD, VH, and retinal break groups) according to their primary diagnosis. The average age at presentation, visual acuities, refractive error, axial length, gestational age, birth weight, acute ROP classification, prior treatments for acute ROP, postoperative visual acuity (VA), and concomitant eye conditions in the 3 groups were documented and compared.

MAIN OUTCOME MEASURES

Clinical features and visual outcomes of late vitreoretinal complications in patients with regressed ROP.

RESULTS

A total of 264 eyes of 238 patients were included. The prior acute ROP status was comparable among the 3 groups, except that the VH group had a higher proportion of patients with type 1 ROP (P = 0.03) and prior treatment (P < 0.001) than the other groups. The average age at presentation was earlier in the RD (20.3 ± 15.5 years) and VH (21.4 ± 18.9 years) groups than in the retinal break group (31.9 ± 18.2 years; P < 0.001). The retinal break group had the best presenting best-corrected VA, followed by the RD and VH groups (P < 0.001). Surgical intervention improved VA in both the RD and VH groups (both P < 0.05). The overall trend of VA was the most favorable in the retinal break group, followed by that in the VH and RD groups. Cicatricial changes in the fellow retina were observed in > 90% of patients with unilateral involvement.

CONCLUSIONS

Infants with acute ROP remain at a high risk of vision-threatening complications throughout childhood and adulthood. Continual follow-up of patients with ROP is important. When severe complications, such as RD or VH, are detected, timely surgical intervention is necessary to ensure favorable visual outcomes in these patients.

Genetic characterization of 1210 Japanese pedigrees with inherited retinal diseases by whole-exome sequencing

Inherited retinal diseases (IRDs) comprise a phenotypically and genetically heterogeneous group of ocular disorders that cause visual loss via progressive retinal degeneration. Here, we report the genetic characterization of 1210 IRD pedigrees enrolled through the Japan Eye Genetic Consortium and analyzed by whole exome sequencing. The most common phenotype was retinitis pigmentosa (RP, 43%), followed by macular dystrophy/cone- or cone-rod dystrophy (MD/CORD, 13%). In total, 67 causal genes were identified in 37% (448/1210) of the pedigrees. The first and second most frequently mutated genes were EYS and RP1, associated primarily with autosomal recessive (ar) RP, and RP and arMD/CORD, respectively. Examinations of variant frequency in total and by phenotype showed high accountability of a frequent EYS missense variant (c.2528G>A). In addition to the two known EYS founder mutations (c.4957dupA and c.8805C>G) of arRP, we observed a frequent RP1 variant (c.5797C>T) in patients with arMD/CORD.

POS0675 IMPACT OF PAST USE OF DISEASE MODIFYING ANTI-RHEUMATIC DRUGS ON JAK INHIBITOR TREATMENT FOR RHEUMATOID ARTHRITIS - DATA FROM THE FUKUI ISHIKAWA TOYAMA DATABASE OF RHEUMATOID ARTHRITIS

Background

Currently, five types of Janus kinase inhibitors (JAKis) are used for rheumatoid arthritis (RA) treatment. The number of cases in which multiple JAKis have been prescribed is increasing. However, the real-world efficacy and safety of JAKis and related factors require further evaluation.

Objectives

The primary objective of this study was to elucidate the impact of past use of disease-modifying anti-rheumatic drugs on RA treatment using JAKis. The secondary objective was to investigate the safety profiles of these agents in a real-world setting.

Methods

Of the 303 JAKi-treated patients in the Fukui Ishikawa Toyama Database of RA included in this study, 30 had switched from one JAKi to another (JJ group), 214 switched from a biologic agent to a JAKi (BJ group), and 47 were naïve to either biologics or JAKis (NJ group). We compared baseline factors, treatment response, and JAKi continuation rates among the three groups. Factors related to JAKi discontinuation were assessed using Cox regression analysis. Furthermore, we investigated adverse events and reported them using exposure-adjusted incidence rates (EAIR; incidence rates per 100 patient-years).

Results

Data from the 303 cases were analyzed (mean age = 63.6 years; female, 82%; mean RA duration, 176 months). Of the 303 patients, 118, 106, 50, and 29 were treated with tofacitinib, baricitinib, peficitinib, and upadacitinib, respectively, on initial observation. Rate of concomitant use with methotrexate and prednisolone was 52% and 49%, respectively.

Regarding efficacy, no significant differences were observed among the three groups in terms of treatment response and JAKi continuation rates, except for the 6-month treatment response between the JJ and NJ groups. Cox regression analysis of the 303 cases revealed that only past use of JAKis during the disease history was significantly associated with JAKi discontinuation. The Kaplan–Meier method showed that patients who previously used JAKis had significantly shorter median JAKi treatment duration than those without such a history (20.9 vs. 54.7 months; p = 0.012). Treatment response was significantly poor in patients who had previously used JAKis, especially 6 months after treatment initiation.

In terms of safety, the total exposure period for the 303 cases was 495 person-years, and the total number of adverse events was 161 (EAIR, 32.5). There were 12 cases (EAIR, 2.5) of serious infections, 23 cases (EAIR, 5.1) of herpes zoster, 7 cases (EAIR, 1.4) of malignant tumors, and 4 cases (EAIR, 0.8) of MACE. Adverse events led to JAKi discontinuation in 34 patients (EAIR, 6.9); the main causes of adverse events leading to treatment discontinuation were infectious diseases in 10 cases (EAIR, 2) and neoplasms in 4 cases (EAIR, 0.8). Within 1 year of initiating JAKi therapy, 21 patients discontinued treatment owing to adverse events, which accounted for 27% of the reasons for treatment discontinuation.

We also investigated cases of JAKi dose reduction, observed in 42 of the 303 cases. Among them, 10 patients required a re-increase in the JAKi dose, and 13 patients (56.5%) were able to maintain the reduced dose for more than 1 year. The remaining 19 patients were excluded from the analysis because the treatment duration at the lower dose had not exceeded 1 year at the time of data extraction. No difference in disease activity at the time of dose reduction was observed between those who maintained the new dose and those who did not (mean DAS28-CRP: 1.48 ± 0.26 vs. 1.89 ± 0.62).

Conclusion

Past use of JAKis may contribute to decreased response and continuation rates for JAKi treatment. In this study, conducted in Japan, development of herpes zoster was found to the most frequent adverse event among the priority survey items.

Acknowledgements

I have no acknowledgements to declare.

Disclosure of Interests

None declared

Severe foveal hypoplasia and macular degeneration in Stickler syndrome caused by missense mutation in COL2A1 gene

BACKGROUND

The aim is to determine the retinal changes in patients with Stickler syndrome caused by a p.R565C missense mutation of the COL2A1 gene.

METHODS

We reviewed the clinical records of 10 eyes of six patients from two families with the Stickler syndrome. The members of both families were heterozygous for the p.R565C mutation. The clinical features including the visual acuity, fundus appearances, fundus autofluorescence (FAF), optical coherence tomographic (OCT) images, and electroretinograms were examined.

RESULTS

Myopia of -12 diopters (D) to -24 D with an average of -16.8 D was observed in 9 eyes of the 5 patients. The FAF images showed different degrees of hyper and hypoautofluorescent patterns in the macula in all but the two youngest patients (7 of 9 eyes, 78%). The OCT images showed the absence of a foveal pit and destruction of the outer retinal layers in the macular area in all patients. The ellipsoid zone (EZ) in the macular region was disrupted in eight eyes (80%) of which seven were fovea sparing.

CONCLUSION

Two families with Stickler syndrome with the p.R565C mutation showed more severe foveal hypoplasia, macular degeneration, and extensive retinal degeneration. A correlation of the OCT and FAF images with the genotype is helpful in determining the prognosis of Stickler syndrome.

Vitrectomy and external drainage of subretinal fluid containing high concentration of vascular endothelial growth factor for advanced coats disease

This study investigated the surgical outcomes of Coats disease and the role of external drainage (XD) of subretinal fluid (SRF). The study is a multicenter retrospective interventional case series of 26 consecutive eyes of 26 patients who underwent surgeries for advanced Coats disease with retinal detachment. Main outcomes measured were: 1) comparison of complete SRF resolution with or without XD, and 2) variables that were associated with functional postoperative best-corrected visual acuity (BCVA) defined as BCVA of 0.1 or better, 3) intraocular vascular endothelial growth factor (VEGF) levels. Complete SRF resolution was achieved in all 14 eyes in which XD had been performed and in 75% of 12 eyes in which XD had not been performed (P = .03). Multivariable logistic regression analysis revealed that initial BCVA was the only variable associated with functional postoperative BCVA (odds ratio 3.24, 95% CI 0.93–11.33; P = .04). Markedly elevated VEGF levels were noted in the SRF compared with those in the vitreous humor (49,760 ± 52,990 vs. 707 ± 611 pg/mL, P = .03). XD seems to provide better anatomical success than without XD in the treatment of advanced Coats disease as XD could effectively eliminate substantial amount of VEGF in the SRF.

Study protocol for a multicentre, open-label, single-arm phase I/II trial to evaluate the safety and efficacy of ripasudil 0.4% eye drops for retinopathy of prematurity

INTRODUCTION

Retinopathy of prematurity (ROP) is a vascular proliferative disorder that occurs in preterm infants. Existing treatments are only indicated in severe ROP cases due to the high invasiveness and the potential risk of irreversible side effects. We previously elucidated that ripasudil, a selective inhibitor of the Rho-associated protein kinase, has the ability to inhibit abnormal retinal neovascularisation in animal models. In addition, ripasudil eye drops (Glanatec ophthalmic solution 0.4%) have been already used for the treatment of glaucoma. Since eye drop therapy is less invasive, early intervention for ROP is possible. The purpose of this phase I/II trial is to evaluate the safety and efficacy of ripasudil eye drops for preterm infants with ROP.

METHODS AND ANALYSIS

This is a multicentre, open-label, single-arm phase I/II trial. To evaluate the safety and efficacy of ripasudil as much as possible, ripasudil will be administered to all enrolled preterm infants with zone I/II, stage 1, or worse ROP. The safety and efficacy of ripasudil in treated patients will be assessed in comparison to a historical control group. Because this is the first trial of ripasudil in preterm infants, a dose-escalation study (once daily for 1 week, then two times per day for 2 weeks) will be conducted in phase I. After obtaining approval from the independent data and safety monitoring board to continue the trial after the completion of phase I, phase II will be conducted. In phase II, ripasudil eye drops will be administered two times per day for 12 weeks. The primary endpoint in phase II is also safety. Efficacy and pharmacokinetics will be evaluated as secondary endpoints.

ETHICS AND DISSEMINATION

This study protocol was approved by the institutional review board at each of the participating centres. Data will be presented at international conferences and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBERS

NCT04621136 and jRCT2071200047.

Retinal Features of Family Members With Familial Exudative Vitreoretinopathy Caused By Mutations in KIF11 Gene

Purpose

To determine the clinical characteristics of patients and family members with familial exudative vitreoretinopathy (FEVR) caused by mutations in the KIF11 gene.

Methods

Twenty-one patients from 10 FEVR families with mutations in the KIF11 gene were studied. The retinal and systemic features were examined. The genetic analyses performed included Sanger sequencing of the KIF11 gene, whole exome sequencing, as well as array comparative genomic hybridization (CGH) analysis and multiple ligation probe assay (MLPA).

Results

Sequence analysis revealed seven different KIF11 mutations. Array CGH with MLPA revealed two different exon deletions. All probands had advanced FEVR with retinal detachments (RDs) and microcephaly with or without developmental disabilities. Patients with bilateral RDs were more frequently associated with developmental disabilities (P = 0.023). Multimodal imaging of the family members revealed that six of nine patients without RDs (66%) had varying degrees of chorioretinopathy. The retinal folds in FEVR patients were associated with severe retinal avascularization. However, funduscopic changes in the peripheral retina were unremarkable in family members without RDs. A score representing the peripheral vascular anomalies determined from the fluorescein angiograms was lower than that of control eyes of patients with mutations of the Wnt signaling genes (P = 0.0029).

Conclusions

The probands with KIF11 mutations were associated with severe ocular and systemic pathologies, whereas affected family members showed highly variable clinical manifestations. Peripheral vascular anomalies can often be unremarkable in eyes without RDs.

Translational Relevance

These findings highlight more diverse mechanisms that underlie the pathological changes in patients with FEVR.

Homozygous single nucleotide duplication of SLC38A8 in autosomal recessive foveal hypoplasia: The first Japanese case report

PURPOSE

To characterize the clinical and genetic features of a Japanese male patient with foveal hypoplasia caused by a homozygous single nucleotide duplication in the SLC38A8 gene.

METHODS

We performed a comprehensive ophthalmic examination including full-field electroretinography (FF-ERG) and pattern-reversal visual evoked potentials (PR-VEPs). Whole-exome sequencing (WES) was performed to identify the disease-causing variant; Sanger sequencing was used for confirmation.

RESULTS

In the WES analysis, a homozygous single nucleotide duplication (c.995dupG; p.Trp333MetfsTer35) was identified in SLC38A8 of the patient. His unaffected mother carried the variant heterozygously. The patient exhibited hyperopia, congenital nystagmus, low visual acuity, and grade 4 foveal hypoplasia. Slit-lamp examination revealed mild posterior embryotoxon and goniodysgenesis. Fundus examination revealed the absence of foveal hyperpigmentation and foveal avascularity, but there were no retinal degenerative lesions. In the FF-ERG, the amplitudes of rod ERG, standard-flash, and bright-flash ERG were within the normal range; cone-mediated responses also showed nearly normal amplitudes. The PR-VEP findings revealed delayed P100 latencies and decreased amplitudes of the P100 components, but no chiasmal misrouting.

CONCLUSIONS

This report is the first report on the clinical and genetic characteristics of SLC38A8-associated foveal hypoplasia in the Japanese population. This is also the first report of normal rod- and cone-mediated responses in a patient with this disorder.

ULTRA-WIDE FIELD FUNDUS AUTOFLUORESCENCE IMAGING OF EYES WITH STICKLER SYNDROME

PURPOSE

To determine the characteristics of fundus autofluorescence (FAF) images and visual functions in eyes with Stickler syndrome using ultra-widefield FAF images.

METHODS

Forty-six eyes of 26 patients with mutations in the COL2A1 gene underwent ultra-widefield FAF imaging. The eyes were categorized into three types; no signs of abnormal AF, predominantly hyperfluorescent AF (hyper-AF), and predominantly hypofluorescent AF (hypo-AF). Goldmann perimetry was performed on 34 eyes, and line-scan images of the abnormal AF lesions were obtained by swept-source optical coherence tomography in 4 eyes.

RESULTS

Abnormal AF lesions were found in 37 eyes of 21 (80.7%) of the 26 patients. Hyper-AF was found in 15 eyes and hypo-AF was found in 22 eyes. The FAF changes corresponded with the funduscopically observed radial paravascular retinal degeneration. The average age at the examination was significantly younger in patients who had eyes with hyper-AF or no abnormal AF than in those with hypo-AF (12.8 vs. 28.4 years; P = 0.009). Abnormal AF-associated visual field defects were found in 5/10 (50%) eyes with hyper-AF and 17/18 (94%) eyes with hypo-AF. Hyper-AF changes tended to appear before retinal changes were detectable by fluorescein angiography. An absence of the ellipsoid zone and the outer nuclear layer and a thinning of the overall retinal thickness were found corresponding to the hypo-AF lesions in the swept source optical coherence tomography images.

CONCLUSION

Abnormal FAF is characteristic of eyes with Stickler syndrome. Age-related alterations of the FAF was associated with visual field defects and disruption of the photoreceptors and retinal pigment epithelial cells.

Autosomal dominant foveal hypoplasia without visible macular abnormalities and PAX6 mutations

PURPOSE

Autosomal dominant foveal hypoplasia (FVH1) is a rare disorder associated with mutations in the PAX6 gene. As an isolated disease entity, FVH1 does not include ocular disorders such as aniridia, microphthalmia, albinism, and achromatopsia. However, it only includes isolated foveal hypoplasia and foveal hypoplasia with presenile cataract. The purpose of this report is to present our findings in four patients from two families with FVH1 without visible ophthalmic macular abnormalities.

STUDY DESIGN

A review of the medical records of two families with FVH1 and genetic confirmation of mutations in the PAX6 gene.

METHODS

Fundus photographs, optical coherence tomographic (OCT) and OCT angiographic (OCTA) images, and slit-lamp anterior segment findings were determined. The type of mutation of the PAX6 gene was determined.

RESULTS

A 3-year-old girl (Patient 1) had signs and symptoms of an impairment in the development of vision without other retinal abnormalities OU. OCT images showed a shallow foveal pit, and OCTA showed the absence of the foveal avascular zone. The second patient (Patient 2) was a 6-year-old girl with unilateral mild cataract and shallow foveal pits OU. Similar shallow foveal pits were found in her asymptomatic mother (Patient 3) and maternal grandfather (Patient 4). Although the iris and posterior fundus were normal, all patients with FVH1 had goniodysgenesis. Genetic testing of the PAX6 gene revealed that Patient 1 had a novel heterozygous mutation (p.Asn365Lys) as a de novo mutation, and Patients 2, 3 and 4 had a novel heterozygous mutation (p.Pro20Ser).

CONCLUSIONS

Heterozygous mutations in the PAX6 gene can cause FVH1 with nearly normal appearing macula. FVH1 is difficult to diagnose, but detailed observations of the foveal structure and vasculature, and detecting the presence of goniodysgenesis can be helpful in identifying patients with FVH1.

Novel mutations in the COL2A1 gene in Japanese patients with Stickler syndrome

Stickler syndrome is an inherited connective tissue disorder that affects the eyes, cartilage and articular tissues. The phenotypes of Stickler syndrome include congenital high myopia, retinal detachment, premature joint degeneration, hearing impairment and craniofacial anomalies, such as cleft palate and midline facial hypoplasia. The disease is genetically heterogeneous, and the majority of the cases are caused by mutations in the COL2A1 gene. We examined 40 Japanese patients with Stickler syndrome from 23 families to determine whether they had mutations in the COL2A1 gene. This analysis was conducted by examining each patient’s genomic DNA by Sanger sequencing. Five nonsense, 4 splicing and 8 deletion mutations in the COL2A1 gene were identified, accounting for 21 of the 23 families. Different mutations of the COL2A1 gene were associated with similar phenotypes but with different degrees of expressivity.

Improvement of (R)-3-hydroxybutyric acid secretion during Halomonas sp. KM-1 cultivation with saccharified Japanese cedar by the addition of urea

Japanese cedar (Cryptomeria japonica) is a major species in artificial Japanese forests. The Halomonas sp. KM-1 was recently isolated and found to grow effectively on saccharified Japanese cedar wood, resulting in the intracellular storage of poly-(R)-3-hydroxybutyric acid (PHB) under aerobic conditions. Under microaerobic conditions, the extracellular secretion of (R)-3-hydroxybutyric acid ((R)-3-HB) led to the degradation of intracellular PHB. In this study, the production of PHB and the secretion of (R)-3-HB using saccharified Japanese cedar were much improved in cultures that were grown in the presence of urea. The level of intracellular PHB production after 36 h under aerobic cultivation was 23·6 g l(-1) ; after shifting to microaerobic conditions for 24 h, the (R)-3-HB concentration in the medium reached 21·1 g l(-1) . Thus, KM-1 efficiently utilizes saccharified Japanese cedar to produce PHB and secretes (R)-3-HB, making it a practical candidate for use in the industrial production of (R)-3-HB.

SIGNIFICANCE AND IMPACT OF THE STUDY

Japanese cedar is a major species grown in artificial Japanese forests, and its thinning is crucial for the health of artificial forests and the Japanese economy. Halomonas sp. KM-1 grew effectively on saccharified Japanese cedar wood, resulting in intracellular storage of poly-(R)-3-hydroxybutyric acid (PHB) under aerobic conditions. Under microaerobic conditions, extracellular secretion of (R)-3-hydroxybutyric acid ((R)-3-HB) caused intracellular PHB degradation. (R)-3-HB is a chiral compound that is useful in the chemical, health food and pharmaceutical industries. The production of PHB and secretion of (R)-3-HB using saccharified wood was dramatically improved, which may positively affect its future industrial production.

Association analysis of susceptibility candidate region on chromosome 5q31 for tuberculosis

Chromosome 5q31 spans the T helper (Th) 2-related cytokine gene cluster, which is potentially important in Th1/Th2 immune responses. The chromosome 5q23.2-31.3 has been recently identified as a region with suggestive evidence of linkage to tuberculosis in the Asian population. With the aim of fine-mapping a putative tuberculosis susceptibility locus, we investigated a family-based association test between the dense single nucleotide polymorphism (SNP) markers within chromosome 5q31 and tuberculosis in 205 Thai trio families. Of these, 75 SNPs located within candidate genes covering SLC22A4, SLC22A5, IRF1, IL5, RAD50, IL13, IL4, KIF3A and SEPT8 were genotyped using the DigiTag2 assay. Association analysis revealed the most significant association with tuberculosis in haplotypes comprising SNPs rs274559, rs274554 and rs274553 of SLC22A5 gene (P(Global)=2.02 x 10(-6)), which remained significant after multiple testing correction. In addition, two haplotypes within the SLC22A4 and KIF3A region were associated with tuberculosis. Haplotypes of SLC22A5 were significantly associated with the expression levels of RAD50 and IL13. The results show that the variants carried by the haplotypes of SLC22A4, SLC22A5 and KIF3A region potentially contribute to tuberculosis susceptibility among the Thai population.

Genome-wide SNP-based linkage analysis of tuberculosis in Thais

Tuberculosis, a potentially fatal infectious disease, affects millions of individuals annually worldwide. Human protective immunity that contains tuberculosis after infection has not been clearly defined. To gain insight into host genetic factors, nonparametric linkage analysis was performed using high-throughput microarray-based single nucleotide polymorphism (SNP) genotyping platform, a GeneChip array comprised 59 860 bi-allelic markers, in 93 Thai families with multiple siblings, 195 individuals affected with tuberculosis. Genotyping revealed a region on chromosome 5q showing suggestive evidence of linkage with tuberculosis (Z(lr) statistics=3.01, logarithm of odds (LOD) score=2.29, empirical P-value=0.0005), and two candidate regions on chromosomes 17p and 20p by an ordered subset analysis using minimum age at onset of tuberculosis as the covariate (maximum LOD score=2.57 and 3.33, permutation P-value=0.0187 and 0.0183, respectively). These results imply a new evidence of genetic risk factors for tuberculosis in the Asian population. The significance of these ordered subset results supports a clinicopathological concept that immunological impairment in the disease differs between young and old tuberculosis patients. The linkage information from a specific ethnicity may provide unique candidate regions for the identification of the susceptibility genes and further help elucidate the immunopathogenesis of tuberculosis.

Anti-arthritic effects of combined treatment with histone deacetylase inhibitor and low-intensity ultrasound in the presence of microbubbles in human rheumatoid synovial cells

OBJECTIVE

The therapeutic effects of histone deacetylase (HDAC) inhibitor combined with ultrasound (US) (1 MHz, 10% duty factor, 0.1 or 0.2 W/cm(2)) in RA synovial fibroblasts (RASFs) were examined.

METHODS

RASFs were isolated from rheumatoid synovial tissues obtained from patients with RA during total knee arthroplasty. RASFs were treated with an HDAC inhibitor, trichostatin A (TSA), with or without US. Cell viability was estimated using the Trypan blue dye exclusion test and cell cycle was examined by flow cytometry using propidium iodide (PI) staining. Gene expression of cell cycle-related genes cyclin D, cyclin A, cyclin B and p21(WAF1/Cip1) was analysed by semi-quantitative RT-PCR. Detection of apoptosis was examined by flow cytometry using annexin V-FITC and PI staining. Microarray analysis was carried out to profile gene expression of inflammation-related genes.

RESULTS

Dose-dependent decreases in cell viability, cell cycle arrest and apoptosis in RASFs due to TSA were observed. US treatment in the presence of microbubbles increased cellular uptake, but did not induce cell cycle arrest or apoptosis. The combination of TSA and US modulated cell cycle-related gene expression and significantly decreased S phase cells and increased G(2)-M phase cells. US also further enhanced TSA-induced RASF apoptosis and regulated expression of inflammation-related genes.

CONCLUSIONS

HDAC inhibitor in combination with US effectively reduces cell viability and induces apoptosis in RASFs. The combination therapy could be useful to control synovial proliferation and inflammation, since US can be easily applied to targeted joints as local physiotherapy.

Pulmonary Mycobacterium avium complex infection associated with the IVS8-T5 allele of the CFTR gene

BACKGROUND

The T5 allele in intron 8 (IVS8) on specific haplotype backgrounds (e.g., long TG repeats) causes abnormal splicing in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, and is also known to be associated with chronic airway diseases.

OBJECTIVE

To investigate the role of CFTR variations for susceptibility to pulmonary Mycobacterium avium complex (MAC) infection.

PARTICIPANTS

Three hundred patients with pulmonary MAC infection (72 males, 228 females; mean age at onset 61.6 + or - 12.4 years) took part in this study. Diagnosis of MAC infection was based on American Thoracic Society criteria. Clinical profiles were collected and blood samples were genotyped for TG repeats, poly-T and M470V polymorphisms.

RESULTS

We found significantly higher T5 frequency in MAC patients than in healthy controls from our own study (0.035 and 0.005, respectively, P = 0.023) and other reports. Homozygote for the T5 allele was found in two MAC patients. All T5 alleles were associated with longer TG repeats, the TG12 or TG13 allele. Seventeen of the 21 T5 alleles appeared to be associated with the V470 allele. Other polymorphisms did not show any significant differences in frequency.

CONCLUSIONS

These findings suggest that the IVS8 5T allele might be involved in susceptibility to pulmonary MAC infection.

Pulmonary Mycobacterium avium complex infection: association with NRAMP1 polymorphisms

The present study aimed to elucidate risk factors for nonimmunocompromised pulmonary Mycobacterium avium complex (MAC) infection. Epidemiological data and variations of candidate genes for mycobacterial diseases were analysed in 111 patients with pulmonary MAC infection. Four polymorphisms of the human natural resistance-associated macrophage protein (NRAMP)1 gene, the 5'(GT)n, 469+14 G/C, D543N and the 3'untranslated region (3'TGTG) insertion/deletion, were genotyped using PCR-based methods. Fok I and Taq I polymorphisms of the vitamin D receptor gene and -221 X/Y and codon 54 A/B polymorphisms of the mannose binding lectin gene were also evaluated. Females were more susceptible to MAC infection mainly affecting the right middle lobe or lingular segment of the lung. Patients' residence at the onset of the disease was distributed evenly irrespective of a waterfront or city water supply system. As compared with homozygotes for major alleles of the D543N and TGTG insertion/deletion polymorphism of the NRAMP1 gene, heterozygotes containing minor alleles were less often observed in MAC cases than in controls. This genetic effect was more significant in patients without comorbidity but not in patients with comorbidity. Other polymorphisms did not show any association with the MAC infection. The human natural resistance-associated macrophage protein 1 gene might be involved in susceptibility to pulmonary Mycobacterium avium complex infection.

Repair of articular cartilage defects in rabbits using CDMP1 gene-transfected autologous mesenchymal cells derived from bone marrow

OBJECTIVE

Cartilage-derived morphogenetic protein 1 (CDMP1), which is a member of the transforming growth factor-beta superfamily, is an essential molecule for the aggregation of mesenchymal cells and acceleration of chondrocyte differentiation. In this study, we investigated whether CDMP1-transfected autologous bone marrow-derived mesenchymal cells (BMMCs) enhance in vivo cartilage repair in a rabbit model.

METHODS

BMMCs, which had a fibroblastic morphology and pluripotency for differentiation, were isolated from bone marrow of the tibia of rabbits, grown in monolayer culture, and transfected with the CDMP1 gene or a control gene (GFP) by the lipofection method. The autologous cells were then implanted into full-thickness articular cartilage defects in the knee joints of each rabbit.

RESULTS

During in vivo repair of full-thickness articular cartilage defects, cartilage regeneration was enhanced by the implantation of CDMP1-transfected autologous BMMCs. The defects were filled by hyaline cartilage and the deeper zone showed remodelling to subchondral bone over time. The repair and reconstitution of zones of hyaline articular cartilage was superior to simple BMMC implantation. The histological score of the CDMP1-transfected BMMC group was significantly better than those of the control BMMC group and the empty control group.

CONCLUSION

Modulation of BMMCs by factors such as CDMP1 allows enhanced repair and remodelling compatible with hyaline articular cartilage.

Overestimated frequency of a possible emphysema-susceptibility allele when microsomal epoxide hydrolase is genotyped by the conventional polymerase chain reaction-based method

A recent association study suggested that the His113 variant of microsomal epoxide hydrolase (mEPHX) may confer a risk for development of emphysema, presumably by increasing susceptibility to smoking injury. Before considering a possible role of this enzyme in pulmonary disease, we attempted to characterize the genetic polymorphism further. The Tyr/His113 polymorphism within exon 3 of mEPHX was initially examined in 62 healthy individuals by conventional methods involving polymerase chain reaction (PCR)-based determination of a restriction fragment length polymorphism (RFLP). Genomic nucleotide sequences, including the polymorphic site and the downstream primer sequence, were further analyzed in 95 unrelated, healthy Japanese volunteers by single-stranded conformation polymorphism (SSCP) analysis and direct sequencing. Genotyping by the first method (PCR-RFLP) revealed that the allelic distribution in our test population apparently deviated from Hardy-Weinberg equilibrium. Sequence analysis showed that a synonymous nucleotide substitution, AAG to AAA (Lys119), was located just within the published primer site. The AAA at codon 119 was present only in alleles with Tyr113, and its frequency reached 0.31 in our panel of 190 Japanese alleles. This substitution potentially hampered PCR amplification because of the nucleotide mismatch, with the result that the frequency of the Tyr113 variation was underestimated. The frequency of His113, a possible emphysema susceptibility allele of the mEPHX gene, was thus overestimated when human DNA samples were genotyped in the conventional way. Depending on the population(s) tested, this anomaly could represent a pitfall for PCR-based association studies.

Support for an association between HLA-DR1 and schizophrenia in the Japanese population

An increase of HLA-DR1 has been observed in schizophrenia patients from the Japanese population. A decrease of DR4, which was reported in Caucasian patients, has also been found in some of the Japanese studies. This small study further investigated frequencies of HLA-DR1 and DR4 in unrelated Japanese patients with schizophrenia (n = 45) and healthy comparison subjects (n = 117). The number of patients possessing DR1 was higher (10 of 45, 22%) compared with the comparison group (11 of 117, 9.4%, P = 0.03). This may support the previous observation of an increased DR1 frequency in the Japanese patients. When the present data is combined with three previous studies, proportions of the Japanese subjects with DR1 were 98 of 588 schizophrenia patients (16.7%) vs. 93 of 942 comparison subjects (9.9%). However, no difference was observed in DR4 frequencies between the patients (51%) and comparison subjects (44%). Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:725-727, 2000.

Protein-losing enteropathy caused by mesenteric venous thrombosis with protein C deficiency

A 64-year-old man presented with leg edema and hypoproteinemia. His alpha-1 antitrypsin clearance rate of 174 mL/day indicated the presence of protein-losing enteropathy (PLE). Computed tomographic scans demonstrated thickened ileal wall and mesenteric edema. Angiography revealed occlusion in a peripheral branch of the superior mesenteric vein. Furthermore, both the patient and his son had low protein C levels. The patient was treated successfully with partial resection of the ileum. Histologic examination of the resected ileum revealed multiple erosions and submucosal fibrosis with organized venous thrombi in the mesenteric veins. This is the first case report of PLE caused by mesenteric venous thrombosis, and our findings suggest that serum protein was lost through erosion of the ileum caused by ischemia due to mesenteric venous thrombosis.

Structure and chromosome location of human OGG1

OGG1 (alias MMH) encodes an 8-hydroxyguanine glycosylase, functionally homologous to bacterial mutM. Here, we report its genomic structure and fine chromosome location. The human OGG1 gene corresponding to the isoform 1 transcripts, consists of seven exons, spanning 7,421 bps, while an alternative additional exon, utilized for isoform 2, is located approximately 9 kb downstream. TATA-like sequence was not found in the 5'-upstream region, common in so-called "housekeeping" genes. The last 55 bases of the 3' untranslated region in exon 7 were unexpectedly conserved among species, presumably because the 3' end of the CAMK1 gene, which is transcribed convergently on the opposite strand, is overlapped at the 3' end. By radiation hybrid panel mapping, OGG1 was localized between WI-4179 and AFMA216ZG1 at 3p26, proximal to the VHL gene.

Novel (CA)n marker DXYS241 on the nonrecombinant part of the human Y chromosome

The origin of modern humans can be traced by comparing polymorphic sites in either mitochondria or genomic sequences between humans and other primates. The human Y chromosome has both a non-recombining region and X-Y homologous pseudo-autosomal regions. In the nonrecombining region events during evolution can be directly detected. At least a part of homology between Xq21 and Yp11 is a result of rather recent translocations from the X chromosome to the Y chromosome. DNA markers residing in the nonrecombining region of the human Y chromosome are potentially useful in tracing male-specific gene flow in human evolution. However, the number of available markers in the region is limited. Here, we report a novel X-Y homologous (CA)n repeat locus in the nonrecombining region of the Y chromosome. This marker, DXYS241, has several interesting features. Y- and X-chromosome alleles are distinguishable because the Y-chromosome alleles are shorter than the X-chromosome alleles most of the time. We developed 2 primer sets for specific examination of Y- and X-chromosome alleles. The marker should be useful in establishing relationships between populations based on patrilineal gene flow. Sequences homologous to DXYS241 are also found on the X chromosome of primates. Four events during primate evolution that led to the modern human Y chromosome were identified.

Long-term effects of water-soluble corn bran hemicellulose on glucose tolerance in obese and non-obese patients: improved insulin sensitivity and glucose metabolism in obese subjects

We examined the effect of soluble corn bran hemicellulose (CBH, 10 g/day) on glucose control and serum insulin in three groups: patients with impaired glucose tolerance (IGT) with (20 subjects) or without (8 subjects) obesity and with healthy non-obese controls (10 subjects). Long-term supplementation (6 months) with CBH decreased the post oGTT curve for patients with impaired mild Type II diabetes, but not that for the controls. Hemoglobin A1c decreased significantly during CBH supplementation in the obese patients, while the fasting glucose level decreased in all three groups, although not significantly. A decreased serum insulin response by oGTT was found in those patients with IGT. The improved oGTT result was associated with improved insulin release and perhaps with peripheral insulin sensitivity. These findings suggest that CBH at a low dose might contribute to glycemic control and would play a useful role in treating Type II diabetes patients.

YAC and cosmid contigs encompassing the Fukuyama-type congenital muscular dystrophy (FCMD) candidate region on 9q31

Fukuyama-type congenital muscular dystrophy (FCMD), the second most common form of childhood muscular dystrophy in Japan, is an autosomal recessive severe muscular dystrophy associated with an anomaly of the brain. We had mapped the FCMD gene to an approximately 5-cM interval between D9S127 and D9S2111 on 9q31-q33 and had also found evidence for linkage disequilibrium between FCMD and D9S306 in this candidate region. Through further analysis, we have defined another marker, D9S172, which showed stronger linkage disequilibrium than D9S306. A yeast artificial chromosome (YAC) contig spanning 3,5 Mb, which includes this D9S306-D9S172 interval on 9q31, has been constructed by a combination of sequence-tagged site, Alu-PCR, and restriction mapping. Also, cosmid clones subcloned from the YAC were assembled into three contigs, one of which contains D9S2107, which showed the strongest linkage disequilibrium with FCMD. These contigs also allowed us to order the markers as follows: cen-D9S127-(approximately 800 kb)-D9S306 (identical to D9S53)-(approximately 700 kb)-A107XF9-(approximately 500 kb)-D9S172-(approximately 30 kb)-D9S299 (identical to D9S774)-(approximately 120 kb)-WI2269-tel. Thus, we have constructed the first high-resolution physical map of the FCMD candidate region. The YAC and cosmid contigs established here will be a crucial resource for identification of the FCMD gene and other genes in this region.

A novel (CA)n polymorphism on 6p21.1-21.2

A novel highly polymorphic CA repeat locus D6S2213 was identified on human chromosome 6p21.1-21.2. It should be a useful marker for linkage studies on chromosome 6 and also in forensic use.

A human protective protein gene partially overlaps the gene encoding phospholipid transfer protein on the complementary strand of DNA

The entire human protective protein gene has been cloned, and structural analysis revealed that the gene spans 7.5kb and comprises 15 exons. Furthermore, it partially overlaps on the opposite strand with the gene encoding phospholipid transfer protein. This region of DNA on chromosome 20 appears to encode two distinct mRNAs expressing defined functional products, and the mRNAs overlap by 58 nucleotides at their 3'-untranslated ends.