Olfactory dysfunction at six months after coronavirus disease 2019 infection.

OBJECTIVE: This study aimed to assess olfactory dysfunction in patients at six months after confirmed coronavirus disease 2019 infection. METHODS: Coronavirus disease 2019 positive patients were assessed six months following diagnosis. Patient data were recoded as part of the adapted International Severe Acute Respiratory and Emerging Infection Consortium Protocol. Olfactory dysfunction was assessed using the University of Pennsylvania Smell Identification Test. RESULTS: Fifty-six patients were included. At six months after coronavirus disease 2019 diagnosis, 64.3 per cent of patients (n = 36) were normosmic, 28.6 per cent (n = 16) had mild to moderate microsmia and 7 per cent (n = 4) had severe microsmia or anosmia. There was a statistically significant association between older age and olfactory dysfunction. Hospital or intensive care unit admission did not lead to worse olfactory outcomes compared to those managed in the out-patient setting. CONCLUSION: At six months after coronavirus disease 2019 diagnosis, approximately two-thirds of patients will be normosmic. This study is the first to describe six-month outcomes for post-coronavirus disease 2019 patients in terms of olfactory dysfunction.

Leber Hereditary Optic Neuropathy and Longitudinally Extensive Transverse Myelitis.

Leber Hereditary Optic Neuropathy is an inherited optic neuropathy caused by mitochondrial DNA point mutations leading to sudden, painless loss of vision. We report a case of an 8-year-old boy presenting with a radiological phenotype of longitudinally extensive transverse myelitis on a background of severe visual impairment secondary to Leber Hereditary Optic Neuropathy (LHON). He was found to have dual mitochondrial DNA mutations at 14484 (MTND6 gene) and 4160 (MTND1 gene) in a family with a severe form of LHON characterised by not only an unusually high penetrance of optic neuropathy, but also severe extra-ocular neurological complications. The m.14484T>C mutation is a common LHON mutation, but the m.4160T>C mutation is to our knowledge not reported outside this family and appears to drive the neurological manifestations. To our knowledge there have been no previous reports of spinal cord lesions in children with LHON.

Emerging Mitochondrial Therapeutic Targets in Optic Neuropathies.

Optic neuropathies are an important cause of blindness worldwide. The study of the most common inherited mitochondrial optic neuropathies, Leber hereditary optic neuropathy (LHON) and autosomal dominant optic atrophy (ADOA) has highlighted a fundamental role for mitochondrial function in the survival of the affected neuron-the retinal ganglion cell. A picture is now emerging that links mitochondrial dysfunction to optic nerve disease and other neurodegenerative processes. Insights gained from the peculiar susceptibility of retinal ganglion cells to mitochondrial dysfunction are likely to inform therapeutic development for glaucoma and other common neurodegenerative diseases of aging. Despite it being a fast-evolving field of research, a lack of access to human ocular tissues and limited animal models of mitochondrial disease have prevented direct retinal ganglion cell experimentation and delayed the development of efficient therapeutic strategies to prevent vision loss. Currently, there are no approved treatments for mitochondrial disease, including optic neuropathies caused by primary or secondary mitochondrial dysfunction. Recent advances in eye research have provided important insights into the molecular mechanisms that mediate pathogenesis, and new therapeutic strategies including gene correction approaches are currently being investigated. Here, we review the general principles of mitochondrial biology relevant to retinal ganglion cell function and provide an overview of the major optic neuropathies with mitochondrial involvement, LHON and ADOA, whilst highlighting the emerging link between mitochondrial dysfunction and glaucoma. The pharmacological strategies currently being trialed to improve mitochondrial dysfunction in these optic neuropathies are discussed in addition to emerging therapeutic approaches to preserve retinal ganglion cell function.

Multiple prenatal ultrasound scans and ocular development: 20-year follow-up of a randomized controlled trial.

OBJECTIVES: Through comprehensive ophthalmic examination of adult offspring we sought to determine the impact of multiple prenatal ultrasound scans on ocular development. METHODS: 2743 pregnant women recruited to the Western Australian Pregnancy (Raine) Cohort study during 1989-1991 were randomized to receive at King Edward Memorial Hospital, Western Australia either multiple prenatal ultrasound scans and Doppler flow studies (intensive group) or a single ultrasound scan at 18 weeks' gestation. Neonatal birth weight of the offspring and other physical measurements were collected prospectively. At age 20 years, participants underwent a comprehensive ophthalmic examination including measurement of ocular biometry and visual acuity. RESULTS: Complete data were available for 1134 adult offspring participants. The mothers of 563 of these had been randomized to receive multiple prenatal ultrasound scans. The mean age of participants at follow-up was 20.0 years. There was no statistically significant difference between the two groups with regard to ocular biometric or visual outcomes, except for slightly higher intraocular pressure identified in individuals exposed to multiple ultrasound scans (P = 0.034). Although infants in the intensive-ultrasound arm were more likely to have birth weights in the lower quartiles, this was not reflected in adult eye development. Axial length, lens thickness, corneal curvature and thickness and optic cup to disc ratio (a risk factor for glaucomatous optic neuropathy) were not significantly influenced by the more frequent ultrasound protocol. CONCLUSIONS: Prior to this study, there was a paucity of safety data for ultrasound with regard to eye development. We found that frequent in-utero exposure to ultrasound, including B-mode imaging and the use of spectral Doppler mode from 18 weeks' gestation, had no significant impact on visual outcomes or ocular biometry.

A puzzle over several decades: eye anomalies with FRAS1 and STRA6 mutations in the same family.

Fraser syndrome (FS) and microphthalmia syndromic 9 (MCOPS9) are autosomal recessive conditions with distinct, and some overlapping features affecting the ocular, respiratory and cardiac systems. Mutations in FRAS1 and FREM2 occur in FS, and mutations in STRA6 occur in MCOPS9. We report two sibships, in the same family, where four deceased offspring had ocular, respiratory and cardiac abnormalities. Two sibs with microphthalmia had syndactyly and laryngeal stenosis, suggesting a clinical diagnosis of FS. Our results indicate that they were compound heterozygotes for novel FRAS1 mutations, p.Cys729Phe and p.Leu3813Pro. The other two sibs, first cousins to the first sib pair, had anophthalmia, lung hypoplasia and cardiac anomalies, suggesting a retrospective diagnosis of MCOPS9. Our results indicate compound heterozygous STRA6 mutations, a novel frameshift leading to p.Tyr18* and a p.Thr644Met mutation. The one surviving individual from these sibships is heterozygous for the p.Tyr18*STRA6 mutation and has bilateral ocular colobomata and microphthalmia. This work emphasises the need for careful phenotypic characterisation to determine genes for assessment in ocular syndromic conditions. It also indicates that heterozygous STRA6 mutations may rarely contribute to microphthalmia and coloboma.

Pediatric cataract, myopic astigmatism, familial exudative vitreoretinopathy and primary open-angle glaucoma co-segregating in a family.

PURPOSE: To describe an Australian pedigree of European descent with a variable autosomal dominant phenotype of: pediatric cortical cataract (CC), asymmetric myopia with astigmatism, familial exudative vitreoretinopathy (FEVR), and primary open-angle glaucoma (POAG). METHODS: Probands with CC, FEVR, and POAG were enrolled in three independent genetic eye studies in Tasmania. Genealogy confirmed these individuals were closely related and subsequent examination revealed 11 other family members with some or all of the associated disorders. RESULTS: Twelve individuals had CC thought to be of childhood onset, with one child demonstrating progressive lenticular opacification. One individual had severe retinal detachment while five others had dragged retinal vessels. Seven individuals had POAG. Seven individuals had myopia in at least one eye ≤-3 Diopters. DNA testing excluded mutations in myocilin, trabecular meshwork inducible glucocorticoid response (MYOC) and tetraspanin 12 (TSPAN12). Haplotype analysis excluded frizzled family receptor 4 (FZD4) and low density lipoprotein receptor-related protein 5 (LRP5), but only partly excluded EVR3. Multipoint linkage analysis revealed multiple chromosomal single-nucleotide polymorphisms (SNPs) of interest, but no statistically significant focal localization. CONCLUSIONS: This unusual clustering of ophthalmic diseases suggests a possible single genetic cause for an apparently new cataract syndrome. This family's clinical ocular features may reflect the interplay between retinal disease with lenticular changes and axial length in the development of myopia and glaucoma.

Distribution of conjunctival ultraviolet autofluorescence in a population-based study: the Norfolk Island Eye Study.

OBJECTIVE: The objective of this study was to describe the distribution of conjunctival ultraviolet autofluorescence (UVAF) in an adult population. METHODS: We conducted a cross-sectional, population-based study in the genetic isolate of Norfolk Island, South Pacific Ocean. In all, 641 people, aged 15 to 89 years, were recruited. UVAF and standard (control) photographs were taken of the nasal and temporal interpalpebral regions bilaterally. Differences between the groups for non-normally distributed continuous variables were assessed using the Wilcoxon-Mann-Whitney ranksum test. Trends across categories were assessed using Cuzick's non-parametric test for trend or Kendall's rank correlation τ. RESULTS: Conjunctival UVAF is a non-parametric trait with a positively skewed distribution. Median amount of conjunctival UVAF per person (sum of four measurements; right nasal/temporal and left nasal/temporal) was 28.2 mm(2) (interquartile range 14.5-48.2). There was an inverse, linear relationship between UVAF and advancing age (P<0.001). Males had a higher sum of UVAF compared with females (34.4 mm(2) vs 23.2 mm(2), P<0.0001). There were no statistically significant differences in area of UVAF between right and left eyes or between nasal and temporal regions. CONCLUSION: We have provided the first quantifiable estimates of conjunctival UVAF in an adult population. Further data are required to provide information about the natural history of UVAF and to characterise other potential disease associations with UVAF. UVR protective strategies should be emphasised at an early age to prevent the long-term adverse effects on health associated with excess UVR.

Best's macular dystrophy in Australia: phenotypic profile and identification of novel BEST1 mutations.

PURPOSE: (1) To evaluate the spectrum of BEST1 mutations within Australian Best Disease or vitelliform macular dystrophy (VMD) pedigrees, including any novel mutations; (2) to analyse the range of clinical presentations of this cohort; (3) to determine any possible genotype-phenotype correlations and (4) to compare clinical data of patients with phenotypic VMD, both with and without a BEST1 mutation. PATIENTS AND METHODS: Patients with suspected VMD were referred to clinical centres for ophthalmological assessment and genetic screening. When a mutation was identified in a proband, further family members were invited for clinical and genetic screening. RESULTS: We identified 42 patients with one of 13 BEST1 mutations. Seven mutations were novel. There were a further 14 probands in whom a BEST1 mutation was not identified. Median visual acuity in both VMD (mutation positive) and clinical VMD (no BEST1 mutation identified) groups reached driving standards (6/12 or better). CONCLUSION: We did not identify any firm genotype-phenotype correlations in our Australian VMD pedigrees, in which there was a spectrum of BEST1 mutations and marked variation in clinical presentation. Genetic screening remains the gold standard for VMD diagnosis. Patients should be counselled that visual acuity might remain at or above driving standards in at least one eye even in the presence of a BEST1 mutation.

Blepharoptosis in children: our experience at the light of literature.

AIMS: We herein report a 5 years experience of management and care of children presenting blepharoptosis at the light of the literature regarding this uncommon pathology. This report aims to display the most common causes of blepharoptosis and its possible treatment. PATIENTS AND METHODS: Clinical and epidemiological data collected from our institution, over a fi ve year period, on 60 patients, 37 males and 23 females with a mean age of 5.4 years (range 0.6 to 15.6 years) affected by blepharoptosis were analyzed. RESULTS: Ptosis was unilateral in 39/60 patients (65%) and bilateral in 21/60 (35%). The causes of ptosis were myogenic (40%), and neurogenic (35%), most commonly congenital. Among the neurogenic ptosis, the most frequent causes were PTOS type 1 and Marcus-Gunn syndrome. All the cases of acquired neurogenic ptosis were associated with paralysis of the oculomotor nerve. Ptosis plus was found in 23.3% of the patients, mechanical origin was present in 1.7% of patients. Family history was positive in the 10% of the patients. CONCLUSIONS: Our series reflect the range of ptosis of the general pediatric population. This study highlights the high degree of heterogeneity in patients with ptosis; only with an accurate analysis of the family and patient history and of the clinical features it is possible to perform an accurate diagnosis, finding the genetic causes and an adequate treatment.

Comparison of three methods of intraocular pressure measurement and their relation to central corneal thickness.

PURPOSE: The purpose of this study was to compare the reliability of the 'gold standard' Goldmann applanation tonometer (GAT), with that of the ocular response analyser (ORA), and the dynamic contour tonometer (DCT). PATIENTS AND METHODS: A total of 694 subjects were recruited to participate from the TwinsUK (UK Adult Twin Registry) at St Thomas' Hospital, London. Intraocular pressure (IOP) was measured using GAT, ORA, and the DCT. The agreement between the three methods was assessed using the Bland-Altman method. Repeatability coefficients and coefficient of variation between first and second readings of the same eye were used to assess reliability. RESULTS: Mean age was 57.5 years (SD, 13.1; range, 16.1-88.5). The mean IOPs, calculated using the mean of two readings from the right eye were as follows: Goldmann (GAT), 14.1+/-2.8 mm Hg; IOPg (ORA), 15.9+/-3.2 mm Hg; IOPcc (ORA), 16.6+/-3.2 mm Hg; and DCT, 16.9+/-2.7 mm Hg. The 95% limits of agreement were for ORA (IOPcc): GAT, -2.07 to 7.18 mm Hg; for DCT: GAT, -0.49 to 6.21 mm Hg; and for DCT: ORA (IOPcc), -3.01 to 4.85 mm Hg. Coefficients of variation for the three tonometers were GAT, 8.3%; ORA, 8.2%; DCT, 6.3%. The repeatability coefficients were 3.4 mm Hg for GAT, 3.57 mm Hg for ORA and 3.09 mm Hg for DCT. GAT and ORA (IOPg) readings showed a positive correlation with central corneal thickness (P<0.005). CONCLUSIONS: This study found similar reliability in all three tonometers. Bland-Altman plots showed the three instruments to have 95% limits of agreement outside the generally accepted limits, which means they are not interchangeable. GAT measurements were found to be significantly lower than the two newer instruments.

Mortality in primary open-angle glaucoma: 'two cupped discs and a funeral'.

PURPOSE: The aim of this study was to investigate the causes of mortality in individuals with open-angle glaucoma (OAG). METHODS: All-cause mortality data from the Registry of Births, Deaths and Marriages for the Australian state of Tasmania, for all people who were at least 40 years of age at the time of death, were classified using International Classification of Diseases-10 guidelines. This information was cross-referenced to identify participants in the Glaucoma Inheritance Study in Tasmania (GIST) who had died. Contingency tables were used for crude analysis and then models were constructed, adjusting for age at death as well as gender. RESULTS: Between 1996 and 2005, a total of 33 879 deaths were recorded. Data were unavailable for 4868 (14.4%) people. The mean age at death for the study sample was 78.4+/-11.5 (range 41-109) years. Of those cases known to have OAG by their participation in GIST (n=2409), full mortality data were available for 741 (92.0%). Following adjustment for the age at death and male gender, the odds ratio for death due to ischaemic heart disease in people with OAG compared to the general population not known to have OAG was significant (OR=1.30, 95% CI: 1.08-1.56; P=0.006). Crude analysis revealed that there were significantly fewer people with OAG who died due to metastatic cancer (P<0.001); however, this did not remain significant following adjustment for age and gender. CONCLUSION: The pathoaetiological relationship between OAG and ischaemic heart disease is unclear and requires further investigation. Increased awareness of the association between cardiovascular disease and OAG is warranted.

RPGR ORF15 genotype and clinical variability of retinal degeneration in an Australian population.

BACKGROUND: Mutations in the retinitis pigmentosa GTPase regulator gene (RPGR) are estimated to cause up to 20% of all Caucasian retinitis pigmentosa and up to 75% of cases of X-Linked RP (XLRP). Exon open reading frame 15 (ORF15) is a purine-rich mutation hotspot. Mutations in RPGR ORF15 have also been documented to cause X linked cone-rod dystrophy (XLCORD) and atrophic macular degeneration at an unknown frequency. METHODS: From a hospital clinic population, probands with probable XLRP and XLCORD were screened for RPGR ORF15 mutations and fully phenotyped. RESULTS: Four different RPGR ORF15 mutations were found in four probands. All mutations in the ORF15 exon resulted in premature truncation of the RPGR protein. Three were nonsense mutations: c.507G>T (p.E169stop), c.867G>T (p.G289stop), c.897G>T (p.E299stop) and the fourth a single nucleotide insertion c.1558-1559insA (p.S522fs 525stop). One family exhibited typical XLRP, two XLCORD and one a combination of the phenotypes. CONCLUSION: RPGR ORF15 mutations produce intrafamilial and interfamilial clinical variability with varying degrees of cone degeneration. In an Australian clinic population RPGR ORF15 mutations cause XLCORD in addition to XLRP.

The natural history of OPA1-related autosomal dominant optic atrophy.

BACKGROUND/AIMS: Autosomal dominant optic atrophy (ADOA) is a genetically heterogenous disease. However, a large proportion of this disease is accounted for by mutations in OPA1. The aim of this longitudinal study was to investigate disease progression in Australian ADOA patients with confirmed OPA1 mutations. METHODS: Probands with characteristic clinical findings of ADOA were screened for OPA1 mutations, and relatives of identified mutation carriers were invited to participate. Disease progression was determined by sequential examination or using historical records over a mean of 9.6 (range 1-42) years. RESULTS: OPA1 mutation carriers (n = 158) were identified in 11 ADOA pedigrees. Sixty-nine mutation carriers were available for longitudinal follow-up. Using the right eye as the default, best-corrected visual acuity (BCVAR) remained unchanged (defined as visual acuity at or within one line of original measurement) in 43 patients (62%). BCVAR worsened by 2 lines in 13 patients (19%). BCVAR deteriorated by more than 2 lines in six patients (9%). Ten per cent of patients had an improvement in visual acuity. Mean time to follow-up was 9.6 years with the mean visual acuity being 6/18 for both the initial and subsequent measurements. There was no statistical significance in the rate of BCVAR loss across different OPA1 mutations (p = 0.55). CONCLUSION: OPA1-related ADOA generally progresses slowly and functional visual acuity is usually maintained. Longitudinal disease studies are important to enable appropriate counselling of patients. This study enables a better understanding of the natural history of ADOA.

Heritability of intraocular pressure: a classical twin study.

AIMS: To estimate the heritability of intraocular pressure (IOP) by performing a classical twin study and to determine whether the use of different instruments influences calculation of eye IOP heritability. METHODS: Twin pairs were recruited to participate from the TwinsUK Adult Twin Registry at St. Thomas' Hospital London. IOP was measured using Goldmann applanation tonometry (GAT). A subset of twins also had their IOP measured using the Ocular Response Analyser (ORA; Reichert, Buffalo, NY) and the Dynamic Contour Tonometer (DCT, Pascal; Swiss Microtechnology AG, Port, Switzerland). We compared the covariance of IOP within monozygotic (MZ) and dizygotic (DZ) pairs using genetic modelling techniques to determine the relative contribution of genes and environment to the variation in IOP seen in this population. RESULTS: Data for 422 twin pairs (211 MZ; 211 DZ) were analysed. The mean IOP for GAT was 15.4 (SD 2.7) mm Hg (range: 8.7-26.2 mm Hg). The MZ correlations were significantly higher than DZ for IOP measured by GAT, DCT and ORA (correlation coefficients: GAT: 0.57:0.39, DCT: 0.62:0.36, Goldmann-correlated ORA (IOPg) 0.73:0.47, for MZ:DZ twins, respectively). Modelling suggested heritability for GAT IOP of 0.62, with individual environmental factors accounting for 0.38 of the variation. CONCLUSION: This study demonstrated that genetic effects are important in determining IOP in this twin population. IOP readings differed depending upon the instrument used, and this resulted in different heritability values; genetic factors explained 62%, 63% and 74% of the variation in IOP using GAT, DCT and ORA IOPg, respectively. Environmental factors determined the remainder of the variation.

The association between maternal smoking in pregnancy, other early life characteristics and childhood vision: the Twins Eye Study in Tasmania.

PURPOSE: To investigate the association between maternal smoking in pregnancy, early-life environment and childhood vision. METHODS: Twin and triplet children enrolled in the Twins Eye Study in Tasmania underwent a comprehensive ophthalmic examination and their parents/guardians retrospectively answered a questionnaire regarding crawling, walking and other measures. A subset of these twins was also in the Tasmanian Infant Health Survey, which prospectively collected data on antenatal smoking, gestation, birth weight and other factors. RESULTS: The mean age of the 346 individuals (172 multiple birth sets) at the time of examination was 9.25+/-2.4 years. Mean unaided visual acuity was 0.0 (6/6). The mean spherical equivalent was +0.87D, and decreased with increasing child age (p<0.01). A prospective analysis, accounting for birth set clustering and relevant confounders, showed increasing levels of maternal smoking in the third trimester was associated with poor stereoacuity on the Titmus test (worse (>) than 100'', p=0.05) and Lang test (p=0.001) and also with the presence of esotropia (p=0.02). These associations persisted after adjustment for infant postnatal smoke exposure at one month of age. Poor stereoacuity on Titmus stereo test circles was associated with late age of first crawling (RR=1.23 (1.06, 1.42) p=0.005 per month) and late age of first walking (RR 1.18 (1.05, 1.22) p=0.001 per month). CONCLUSIONS: Antenatal smoking was independently associated with poor stereovision and the presence of esotropia. Poor stereoacuity may be associated with delayed age at first crawling or walking.

Prevalence of CYP1B1 mutations in Australian patients with primary congenital glaucoma.

Analysis of CYP1B1 in primary congenital glaucoma (PCG) patients from various ethnic populations indicates that allelic heterogeneity is high, and some mutations are population specific. No study has previously reported the rate or spectrum of CYP1B1 mutations in Australian PCG patients. The aim of this study is to determine the frequency of CYP1B1 mutations in our predominately Caucasian, Australian cohort of PCG cases. Thirty-seven probands were recruited from South-Eastern Australia, along with 100 normal control subjects. Genomic DNA was extracted and the coding regions of CYP1B1 analysed by direct sequencing. Sequence analysis identified 10 different CYP1B1 disease-causing variants in eight probands (21.6%). Five subjects were compound heterozygotes, two subjects heterozygous and one homozygous for CYP1B1 mutations. Three missense mutations are novel (D192Y, G329D, and P400S). None of the novel mutations identified were found in normal controls. One normal control subject was heterozygous for the previously reported CYP1B1 R368H mutation. Six previously described probable polymorphisms were also identified. Mutations in CYP1B1 account for approximately one in five PCG cases from Australia. Our data also supported the high degree of allelic heterogeneity seen in similar studies from other ethnic populations, thereby underscoring the fact that other PCG-related genes remain to be identified.

The role of the Met98Lys optineurin variant in inherited optic nerve diseases.

AIMS: To investigate the role of the common OPTN Met98Lys variant as a risk allele in open-angle glaucoma (OAG), autosomal dominant optic atrophy (ADOA) and Leber's hereditary optic neuropathy (LHON). METHODS: The presence of the Met98Lys variant was determined in a total of 498 (128 with normal-tension glaucoma (NTG)) patients with OAG, 29 patients who had myocilin-related OAG, 101 patients from ADOA pedigrees, 157 patients from LHON pedigrees and 218 examined OAG age-matched normal controls. RESULTS: 17 of 218 (7.8%) controls had the Met98Lys variant. 28 (5.6%) patients with OAG were Met98Lys positive. More Met98Lys carriers were found in the NTG group than in the high-tension glaucoma (HTG) group (p = 0.033). However, no significant difference was observed between the NTG and control cohorts (p = 0.609). Two MYOC mutation carriers were found to have the variant. The variant was found in 1 of 10 pedigrees with ADOA and in 8 of 35 pedigrees with LHON. CONCLUSION: Data from this study do not support a strong role for the OPTN Met98Lys variant in glaucoma, ADOA or LHON. However, a weak association was observed of the variant with NTG compared with that with HTG. Meta-analysis of all published data on the variant and glaucoma confirmed that the association, although weak, is highly statistically significant in the cohort with glaucoma versus controls.

Nail-patella syndrome and its association with glaucoma: a review of eight families.

BACKGROUND: Nail-patella syndrome (NPS) is a rare autosomal dominant syndrome, characterised by dysplasia of the nails, patellae, elbows and iliac horns. Mutations in the LMX1B gene were found in four North American families in whom glaucoma cosegregated with NPS. AIMS: To investigate the association of glaucoma with NPS in Australian families and to determine how common NPS is in Australia. METHODS: One family with NPS and glaucoma was identified from the Glaucoma Inheritance Study in Tasmania. A further 18 index cases of NPS were identified from the genetics database for southeastern Australia. Eight of these pedigrees were available for comprehensive glaucoma examination on available family members. DNA was sequenced for mutations in LMX1B. RESULTS: In total, 52 living cases of NPS were identified suggesting a minimum prevalence of at least 1 in 100 000. 32 subjects from eight NPS pedigrees (four familial and four sporadic cases) were examined. 14 subjects had NPS alone. 4 subjects had NPS and glaucoma or ocular hypertension. Five pedigrees with NPS had a reported family history of glaucoma, although some of these people with glaucoma did not have NPS. LMX1B mutations were identified in 5 of the 8 index cases-three sporadic and two familial. Two of the six (33%) participants over 40 years of age had developed glaucoma, showing increased risk of glaucoma in NPS. CONCLUSION: Patients with NPS should be examined regularly for glaucoma. However, because the families with NPS are ascertained primarily from young probands or probands who are isolated cases, the exact level of risk is unclear.

Lack of association of p53 polymorphisms and haplotypes in high and normal tension open angle glaucoma.

BACKGROUND: The final common pathway for open angle glaucoma (OAG) is retinal ganglion cell apoptosis. Polymorphisms in p53, a major regulator of apoptosis, affect the efficiency of cell death induction. Association studies of p53 haplotypes and OAG have had conflicting results. OBJECTIVE: To examine the association between p53 haplotypes and OAG in a larger white population than in previous reports, and extend the analysis to normal tension glaucoma. METHODS: 345 unrelated people with OAG were recruited (283 subjects with high tension glaucoma and 62 with normal tension glaucoma) and compared with 178 age matched controls. Genomic DNA was analysed for the p53 codon 72 Arg/Pro polymorphism as well as for the presence or absence of a 16 bp intron 3 insertion. RESULTS: In this white cohort no association was found between glaucoma (high or normal tension) and either sequence variant or haplotype. CONCLUSIONS: The p53 codon 72 Arg/Pro polymorphism is not associated with age of onset or severity of glaucoma.

The telomere of human chromosome 1p contains at least two independent autosomal dominant congenital cataract genes.

AIMS: Multiple genetic causes of congenital cataract have been identified, both as a component of syndromes and in families that present with isolated congenital cataract. Linkage analysis was used to map the genetic locus in a six generation Australian family presenting with total congenital cataract. METHODS: Microsatellite markers located across all known autosomal dominant congenital cataract loci were genotyped in all recruited family members of the Tasmanian family. Both two point and multipoint linkage analysis were used to assess each locus under an autosomal dominant model. RESULTS: Significant linkage was detected at the telomere of the p arm of chromosome 1, with a maximum two point LOD of 4.21 at marker D1S507, a maximum multipoint exact LOD of 5.44, and an estimated location score of 5.61 at marker D1S507. Haplotype analysis places the gene inside a critical region between D1S228 and D1S199, a distance of approximately 6 megabases. The candidate gene PAX7 residing within the critical interval was excluded by direct sequencing in affected individuals. CONCLUSION: This is the third report of congenital cataract linkage to 1ptel. The critical region as defined by the shared haplotype in this family is clearly centromeric from the Volkmann cataract locus identified through study of a Danish family, indicating that two genes causing autosomal dominant congenital cataract map to the telomeric region of chromosome 1p.