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Biomedical subjects

Edwin M Stone

Publications and source records attributed to Edwin M Stone.

At least 55 records · Page 3Linked to original sources
PubMed2004

Bardet-Biedl syndrome type 4 (BBS4)-null mice implicate Bbs4 in flagella formation but not global cilia assembly.

The functions of the proteins encoded by the Bardet-Biedl syndrome (BBS) genes are unknown. Mutations in these genes lead to the pleiotropic human disorder BBS, which is characterized by obesity, retinopathy, polydactyly, renal and cardiac malformations, learning disabilities, and hypogenitalism. Secondary features include diabetes mellitus and hypertension. Recently, it has been suggested that the BBS phenotypes are the result of a lack of cilia formation or function. In this study, we show that mice lacking the Bbs4 protein have major components of the human phenotype, including obesity and retinal degeneration. We show that Bbs4-null mice develop both motile and primary cilia, demonstrating that Bbs4 is not required for global cilia formation. Interestingly, male Bbs4-null mice do not form spermatozoa flagella, and BBS4 retinopathy involves apoptotic death of photoreceptors, the primary ciliated cells of the retina. These mutation data demonstrate a connection between the function of a BBS protein and cilia. To further evaluate an association between cilia and BBS, we performed homology comparisons of BBS proteins in model organisms and find that BBS proteins are specifically conserved in ciliated organisms.

Animals↗
PubMed2004

QRX, a novel homeobox gene, modulates photoreceptor gene expression.

A novel paired-like homeobox gene, designated as Qrx, was identified by a yeast one-hybrid screen using the bovine Rhodopsin promoter Ret-1 DNA regulatory element as bait. Qrx is preferentially expressed in both the outer and inner nuclear layers of the retina. Its homeodomain is nearly identical to that of Rx/Rax, a transcription factor that is essential for eye development, but it shares only limited homology elsewhere. Although Qrx and Rx/Rax show similar DNA binding properties in vitro, the two proteins demonstrate distinct target selectivity and functional behavior in promoter activity assays. QRX synergistically increases the transactivating function of the photoreceptor transcription factors Crx and NRL and it physically interacts with CRX. Qrx is present in the bovine and human genomes, but appears to be absent from the mouse genome. Nonetheless, a 5.8 kb upstream region of human QRX is capable of directing expression in presumptive photoreceptor precursor cells in transgenic mice. These results indicate that Qrx may be involved in modulating photoreceptor gene expression. In addition, the finding of rare heterozygous QRX sequence changes in three individuals with retinal degeneration raises the possibility that QRX may be involved in disease pathogenesis.

Amino Acid Sequence↗
PubMed2004

Mutations in ABCA4 result in accumulation of lipofuscin before slowing of the retinoid cycle: a reappraisal of the human disease sequence.

Mutations in ABCA4, which encodes a photoreceptor specific ATP-binding cassette transporter (ABCR), cause autosomal recessive forms of human blindness due to retinal degeneration (RD) including Stargardt disease. The exact disease sequence leading to photoreceptor and vision loss in ABCA4-RD is not known. Extrapolation from murine and in vitro studies predicts that two of the earliest pathophysiological features resulting from disturbed ABCR function in man would be slowed kinetics of the retinoid cycle and accelerated deposition of lipofuscin in the retinal pigment epithelium (RPE). To determine the human pathogenetic sequence, we studied surrogate measures of retinoid cycle kinetics, lipofuscin accumulation, and rod and cone photoreceptor and RPE loss in ABCA4-RD patients with a wide spectrum of disease severities. There were different extents of photoreceptor/RPE loss and lipofuscin accumulation in different regions of the retina. Slowing of retinoid cycle kinetics was not present in all patients; when present, it was not homogeneous across the retina; and the extent of slowing correlated well with the degree of degeneration. The orderly relationship between these phenotypic features permitted the development of a model of disease sequence in ABCA4-RD. The model predicted lipofuscin accumulation as a key and early component of the disease expression in man, as in mice. In man, however, abnormal slowing of the rod and cone retinoid cycle occurs at later stages of the disease sequence. Knowledge of the human ABCA4 disease sequence will be critical for defining rates of progression, selecting appropriate patients and retinal locations for future therapy, and choosing appropriate treatment outcomes.

ATP-Binding Cassette Transporters↗
PubMed2004

Mutation analysis of NR2E3 and NRL genes in Enhanced S Cone Syndrome.

Ten new and seventeen previously reported Enhanced S Cone Syndrome (ESCS) subjects were used to search for genetic heterogeneity. All subjects were diagnosed with ESCS on the basis of clinical, psychophysical and/or electroretinography testing using published criteria. Mutation analysis was performed on the NR2E3 nuclear receptor gene by single strand conformation analysis and direct sequencing, which revealed either homozygous (N=13) or compound heterozygous (N=11) mutations in 24 subjects (89%), heterozygous mutations in 2 subjects (7%) and no mutations in 1 subject (4%). Fifteen different mutations were identified, including six not previously reported. The subject (Patient A) with no detected NR2E3 mutation had features not usually associated with ESCS, in particular moderate rod photoreceptor function in peripheral retina and an abnormally thick retinal nerve fibre layer. Mutation analysis of the NRL, CRX, NR1D1 and THRB genes in this individual revealed a heterozygous one base-pair insertion in exon 2 of the NRL gene, which results in a predicted truncation of the NRL protein. Loss-of-function NRL alleles have not been described previously in humans, but since the same mutation was present in unaffected family members, it raises the possibility that the abnormal ESCS phenotype in Patient A may result from a digenic mechanism, with a heterozygous NRL mutation and a mutation in another unknown gene.

Abnormalities, Multiple↗
PubMed2004

A novel IMPDH1 mutation (Arg231Pro) in a family with a severe form of autosomal dominant retinitis pigmentosa.

PURPOSE: To define ophthalmic findings in a family with autosomal dominant retinitis pigmentosa and a novel IMPDH1 gene mutation. DESIGN: Genetic and observational family study. PARTICIPANTS: Sixteen affected members of a family with autosomal dominant retinitis pigmentosa. METHODS: Ophthalmic examination, including best-corrected visual acuity (VA), slit-lamp biomicroscopy, direct and indirect ophthalmoscopy, Goldmann kinetic perimetry, and electroretinography were performed. Deoxyribonucleic acid single-strand conformation polymorphism (SSCP) analysis was done. Abnormal polymerase chain reaction products identified by SSCP analysis were sequenced bidirectionally. RESULTS: All affected patients had the onset of night blindness within the first decade of life. Ocular findings were characterized by diffuse retinal pigmentary degenerative changes, marked restriction of peripheral visual fields, severe loss of VA, nondetectable electroretinography amplitudes, and a high frequency of posterior subcapsular lens opacities. Affected members were observed to harbor a novel IMPDH1 gene mutation. CONCLUSION: A novel IMPDH1 gene mutation (Arg231Pro) was associated with a severe form of autosomal dominant retinitis pigmentosa. Families affected with a severe form of this genetic subtype should be investigated for a mutation in the IMPDH1 gene.

Adolescent↗
PubMed2004

Results from screening over 9000 mutation-bearing mice for defects in the electroretinogram and appearance of the fundus.

Random mutagenesis combined with phenotypic screening using carefully crafted functional tests has successfully led to the discovery of genes that are essential for a number of functions. This approach does not require prior knowledge of the identity of the genes that are involved and is a way to ascribe function to the nearly 6000 genes for which knowledge of the DNA sequence has been inadequate to determine the function of the gene product. In an effort to identify genes involved in the visual system via this approach, we have tested over 9000 first and third generation offspring of mice treated with the mutagen N-ethyl-N-nitrosourea (ENU) for visual defects, as evidenced by abnormalities in the electroretinogram and appearance of the fundus. We identified 61 putative mutations with this procedure and outline the steps needed to identify the affected genes.

Animals↗
PubMed2004

Clinical phenotype as a prognostic factor in Stargardt disease.

PURPOSE: To determine the prognostic significance of widespread flecks, described as fundus flavimaculatus, in patients with Stargardt disease. DESIGN: Historical cohort study. SUBJECTS AND METHODS: Patients with Stargardt disease were identified by searching preexisting databases at the University of Iowa and Oregon Health Sciences University. The medical records of these patients were evaluated for the validity of the diagnosis, initial and final visual acuity, length of follow-up, and initial and final phenotype. Phenotype was graded as I, II, or III on the basis of the distribution of flecks and the extent of atrophy. The relationship between final visual acuity and final clinical appearance (phenotype I versus II versus III) was evaluated controlling for length of follow-up and age using a Cochran-Mantel-Haenszel test. The clinical progression of visual acuity loss for each phenotype was analyzed using life tables and Kaplan-Meier survival analysis for age and length of follow-up effects. RESULTS: A total of 214 patients were confirmed to have Stargardt disease; 131 patients were seen at multiple visits. Eighty-two patients were identified with phenotype I, 62 with phenotype II, and 70 with phenotype III. The final visual outcome was significantly better for patients whose ophthalmoscopic abnormalities were limited to the macula (phenotype I): 80 of 82 patients with phenotype I (97.6%) maintained 20/200 or better visual acuity in at least one eye as compared to 40/62 (64.5%) patients with phenotype II and 13/70 (18.6%) patients with phenotype III (P < 0.0001). Survival analysis showed a similarly significant difference in the survival probabilities (likelihood of maintaining 20/200 or better vision) for the three phenotypes considered over age and over follow-up length (P < 0.0001), with phenotypes II and III demonstrating significantly more deterioration in vision over time. CONCLUSIONS: The presence of midperipheral flecks, especially early in life, carries a poorer visual prognosis for patients with Stargardt disease than when disease is limited to the macula. The development of midperipheral flecks is an indicator of more extensive fundus involvement and thus poorer long-term visual prognosis.

Adolescent↗
PubMed2004

Electroretinographic findings in patients with Stargardt disease and fundus flavimaculatus.

PURPOSE: To characterize the clinical and electroretinogram (ERG) features of our cohort of patients with Stargardt disease (STGD) exhibiting coding sequence variations in the ABCA4 gene. METHODS: Review of 76 patients with the clinical diagnosis of Stargardt disease/fundus flavimaculatus (STGD/FF) from the University of Iowa Department of Ophthalmology and Visual Sciences (41 patients) and the Casey Eye Institute (35 patients). Clinical examination, Goldmann perimetry, and electroretinography were performed on all 76 patients. Patients were divided into three groups on the basis of their funduscopic and electroretinographic features: (1) a normal ERG by the standards of the laboratory; (2) minimal rod or cone abnormalities; (3) severe ERG dysfunction. The latter category was further subdivided on the basis of a cone-dominated loss of function (C > R or "cone-rod dystrophy") or diffuse depression of rods and cones (C = R). Mutational analysis of the coding sequence of the ABCA4 gene was performed by single strand conformation polymorphism analysis followed by automated DNA sequencing. Each electroretinographic group was analyzed for the presence of disease causing changes using exact tests of binomial proportions corrected for multiple comparisons by Bonferroni method. Quantitative polymerase chain reaction (QPCR) was performed on patients who were homozygous for disease causing changes in the ABCA4 gene to rule out the possibility of deletions. RESULTS: Overall, 56 of 76 patients (and 77 of 152 alleles) exhibited coding sequence variations that were compatible with high-penetrance disease-causing mutations. The most common of these were His423Arg (9), frameshift mutations (7), Ala1038Val (7), and Pro1380Leu (6). Although no patients with His423Arg presented with normal ERGs, no significant correlation was observed between specific sequence variations and the electroretinographic characteristics or fundus appearance. However, a significantly greater fraction of patients with normal ERG studies failed to exhibit detectable disease-causing coding sequence variations in the ABCA4 gene identified on either allele (P = 0.0006). CONCLUSION: STGD/FF patients in our cohort exhibit a wide range of electroretinographic abnormalities, some of which are more prevalent than previously suspected. No direct correlation between clinical appearance, electrophysiologic characteristics and specific ABCA4 alleles could be identified, although a significantly lower number of our cohort with a normal ERG exhibited detectable coding sequence variations in the ABCA4 gene. However, four patients with ERG dysfunction were homozygous for a His423Arg change proven by QPCR not to be an artifact of a deletion. The presence of electrophysiologic dysfunction is not uncommon in our cohort of patients with STGD. Thus, the ERG provides clinically important information of retinal function for STGD/FF and, as such, is still indicated as part of the evaluation of these patients.

ATP-Binding Cassette Transporters↗
PubMed2004

Attitudes to predictive DNA testing for myocilin glaucoma: experience with a large Australian family.

PURPOSE: Glaucoma is a major cause of visual impairment and blindness in developed countries. Half of those with glaucoma are unaware that they have the disease. Mutations in the myocilin (MYOC) gene are responsible for 3 to 5% of primary open angle glaucoma, thus predictive DNA testing in family members of some glaucoma pedigrees is possible. We wished to determine the attitudes of affected and unaffected family members to the use of predictive DNA testing in glaucoma. SUBJECTS AND METHODS: We surveyed the attitudes of family members from one such pedigree to determine the acceptability of predictive DNA testing. We studied 72 members of a large family in which the MYOC mutation, THR377MET, segregates. Family members were examined over an 8-year period as part of research initiated to identify the gene. Once the mutation was identified, we offered participants the result of their DNA test after a genetic counseling session. Family members were subsequently given a questionnaire about the counseling and DNA result. RESULTS: Most wished to know their result after counseling; 26 of 27 (96%) felt the genetic counseling session was necessary, but participants' attitudes varied as to whether they preferred this in person, by phone, or letter. Forty three patients were resurveyed 5 years after their initial counseling session. No adverse problems relating to the predictive testing were reported, though two had been asked about DNA testing by insurance companies; 5 of 24 (21%) individuals who had been informed they did not carry the mutation were unsure if they carried the mutation 5 years after counseling, while all 19 mutation carriers (who were being examined annually) correctly recalled their mutation status. CONCLUSIONS: This study suggests that predictive glaucoma testing in appropriate circumstances is acceptable to patients and their families.

Attitude to Health↗
PubMed2004

Dark adaptation of rod photoreceptors in normal subjects, and in patients with Stargardt disease and an ABCA4 mutation.

PURPOSE: Psychophysical and electroretinographic (ERG) studies indicate that patients with Stargardt disease exhibit abnormally slow rod dark adaptation after illumination that bleaches a substantial fraction of rhodopsin. However, relatively little information is available concerning rod recovery in this disease after weaker adapting (i.e., conditioning) light. With the use of a paired-flash ERG method, properties of the derived rod response to a low-bleach (<1%) but rod-saturating conditioning flash were investigated in seven normal subjects and in five Stargardt patients with identified sequence variations in the ABCA4 gene. METHODS: In the first of two experiments, the interval between a fixed conditioning flash (67 or 670 scotopic cd s m(-2)) and a bright probe flash of fixed strength was varied to determine the falling-phase kinetics of the derived rod response to the conditioning flash. In the second, the instantaneous amplitude-intensity function for the rod response at an intermediate stage of recovery from the conditioning flash was determined by presenting a test flash of various strengths at a fixed time after the conditioning flash, and a probe flash at 200 ms after the test flash. RESULTS: The maximum peak amplitude of the dark-adapted, rod-mediated a-wave determined in Stargardt patients (211 +/- 87 microV) was on average lower than that determined in normal subjects (325 +/- 91 microV; P = 0.06). The derived rod response to the 670 scotopic cd s m(-2) conditioning flash determined in normal subjects and Stargardt patients exhibited a biphasic recovery, and the kinetics of the early stage of this recovery were similar in the two subject groups. For both normal subjects and patients, normalized amplitude-intensity functions describing the dark-adapted derived rod response exhibited half-saturation at approximately 1.5 log scotopic troland second. In both groups, the normalized amplitude-intensity function determined at approximately 2 seconds after the 67 scotopic cd s m(-2) conditioning flash and at approximately 9 seconds after the 670 scotopic cd s m(-2) conditioning flash exhibited an average desensitization (i.e., an increase of test flash strength at half-saturation) of approximately 0.5 to 0.6 log unit relative to that determined under dark-adapted conditions. CONCLUSIONS: The results indicate that, despite a reduction in the average dark-adapted maximum a-wave amplitude in the Stargardt/ABCA4 patients, the early-stage recovery kinetics of the derived rod response to a low-bleaching conditioning flash as well as the lingering rod desensitization produced by such a flash are similar to those determined in normal subjects.

ATP-Binding Cassette Transporters↗
PubMed2003

Adeno-associated virus type 5: transduction efficiency and cell-type specificity in the primate retina.

Gene transfer using adeno-associated viruses (AAVs) has been effective for treating inherited retinal diseases in animal models. Further evaluation in primates must be performed prior to clinical application, however, because of the difference between the retina of the primate and those of other animals. Prior work has shown that AAV2 can transduce rod-photoreceptor and RPE cells in the non-human primate retina and that AAV5 is more efficient at transducing photoreceptor cells than AAV2 in the rodent retina. In this study, we evaluated the efficiency of AAV5 in the non-human primate retina after subretinal injections of the vector to distinct anatomic retinal regions (superior, inferior, nasal, macula, temporal). rAAV5 led to a rapid onset of transgene expression (within 2 weeks), with expression persisting up to 10 months. Postoperative electrophysiology studies showed that global retinal function was preserved following gene transfer. Quantitative analysis of gene transfer demonstrated a maximum transduction efficiency of 22% in the injected areas. Evaluation of cell types using confocal microscopy and cone-specific antibodies revealed that AAV5, expressing reporter genes from the cytomegalovirus (CMV) promoter/enhancer, preferentially transduced rods. No significant differences were found in the regional tropism of AAV5 among the five areas injected despite variation in retinal topography. Immunohistochemical studies revealed that the AAV5 receptor, PDGFR-A, is localized to the outer segments of rods but not cones providing a basis for the observed tropism. Our results support the utility of AAV5 for rod photoreceptor degeneration therapies.

Adenoviridae↗
PubMed2003

Crumbs homolog 1 (CRB1) mutations result in a thick human retina with abnormal lamination.

Mutations in CRB1, the human homolog of Drosophila Crumbs, cause autosomal recessive blinding disorders of the retina. Whereas Crumbs is implicated in apical-basal epithelial polarity and photoreceptor morphogenesis, the role of CRB1 in normal or diseased retina remains unclear. We characterized the retinal organization in vivo of patients with CRB1 mutations and found that, unlike other inherited retinal degenerations studied to date, the CRB1 mutant retinas are remarkably thick in cross-section and lack the distinct layers of normal adult retina. There are coarse outer and inner zones and a thick surface layer around the optic nerve. The abnormal retinal architecture in CRB1 mutations resembles that of immature normal retina. The results suggest that the CRB1 disease pathway disturbs the development of normal human retinal organization by interrupting naturally occurring apoptosis.

Eye Proteins↗
PubMed2003

Characterization of rabbit myocilin: Implications for human myocilin glycosylation and signal peptide usage.

BACKGROUND: Mutations in the gene encoding human myocilin (MYOC) have been shown to cause juvenile- and adult-onset glaucoma. In addition, myocilin has been associated with glucocorticoid-induced ocular hypertension and steroid-induced glaucoma. To better understand the role myocilin plays in steroid-induced glaucoma and open-angle glaucoma, we examined rabbit myocilin for use in the rabbit animal model of steroid-induced glaucoma. RESULTS: We have cloned the rabbit ortholog of human MYOC. Rabbit MYOC consists of three exons and an open reading frame encoding a 490 amino acid, 54,882-Da protein, which is 14 amino acids shorter at the N-terminus than human myocilin but 84% identical overall. Rabbit myocilin migrates as a single electrophoretic band, vs. double-banded human myocilin, by SDS-PAGE/immunoblot analysis. We determined that the differential migration exhibited is due to an N-glycosylation site that is present in human (Asn57), monkey and mouse myocilin but absent in rabbit (Ser43), rat and bovine myocilin. Rabbit myocilin is secreted in vitro in trabecular meshwork cell culture and in vivo in aqueous humor. Secretion of human myocilin is shown to be dependent on the signal peptide and independent of the extra 14 amino acids not found in rabbit myocilin. Many of the amino acids in myocilin that are mutated in glaucoma patients are conserved across species. CONCLUSION: We have cloned the rabbit MYOC cDNA and determined that rabbit myocilin is secreted but not N-linked glycosylated. Knowledge of the rabbit MYOC cDNA sequence will facilitate future studies in the rabbit animal model examining the role of myocilin in steroid-induced glaucoma and the gain-of-function hypothesis in open-angle glaucoma.

Amino Acid Sequence↗
PubMed2003

Evaluation of complex inheritance involving the most common Bardet-Biedl syndrome locus (BBS1).

Bardet-Biedl syndrome (BBS) is a genetic disorder with the primary features of obesity, pigmentary retinopathy, polydactyly, renal malformations, mental retardation, and hypogenitalism. Patients with BBS are also at increased risk for diabetes mellitus, hypertension, and congenital heart disease. BBS is known to map to at least six loci: 11q13 (BBS1), 16q21 (BBS2), 3p13-p12 (BBS3), 15q22.3-q23 (BBS4), 2q31 (BBS5), and 20p12 (BBS6). Although these loci were all mapped on the basis of an autosomal recessive mode of inheritance, it has recently been suggested-on the basis of mutation analysis of the identified BBS2, BBS4, and BBS6 genes-that BBS displays a complex mode of inheritance in which, in some families, three mutations at two loci are necessary to manifest the disease phenotype. We recently identified BBS1, the gene most commonly involved in Bardet-Biedl syndrome. The identification of this gene allows for further evaluation of complex inheritance. In the present study we evaluate the involvement of the BBS1 gene in a cohort of 129 probands with BBS and report 10 novel BBS1 mutations. We demonstrate that a common BBS1 missense mutation accounts for approximately 80% of all BBS1 mutations and is found on a similar genetic background across populations. We show that the BBS1 gene is highly conserved between mice and humans. Finally, we demonstrate that BBS1 is inherited in an autosomal recessive manner and is rarely, if ever, involved in complex inheritance.

Amino Acid Sequence↗
PubMed2003

ABCA4 gene sequence variations in patients with autosomal recessive cone-rod dystrophy.

OBJECTIVE: To identify sequence variations in the ABCA4 gene in a cohort of patients with autosomal recessive cone-rod dystrophy. METHODS: The coding sequences of the ABCA4 gene were analyzed in 30 unrelated probands. In those patients with plausible disease-causing variations, correlations were made between genotype and fundus phenotype as well as with electrophysiological and visual field findings. RESULTS: Sixteen (53%) of 30 probands were found to harbor plausible disease-causing variations in the ABCA4 gene. Two distinctly different fundus phenotypes were observed in our cohort of patients. Twelve patients showed diffuse pigmentary degenerative changes, whereas 4 showed either no pigmentary changes or only a mild degree of peripheral pigment degeneration. An associa-tion between certain sequence variations and each of these 2 different phenotypes was observed. CONCLUSIONS: Our findings confirm that a substantial percentage of patients with autosomal recessive cone-rod dystrophy are likely to harbor a mutation in the ABCA4 gene as the cause of their disease. The fundus phenotype observed in such patients is quite variable, and certain fundus phenotypes may be more associated with certain genotypes. Clinical Relevance Identification of the molecular genetic basis for various inherited human retinal dystrophies, such as cone-rod dystrophy, facilitates a potentially better understanding of the mechanisms by which photoreceptor cells degenerate. This in turn provides guidance as to how to better proceed in identifying the most optimal future therapeutic strategies.

ATP-Binding Cassette Transporters↗
PubMed2003

Glaucoma phenotype in pedigrees with the myocilin Thr377Met mutation.

OBJECTIVE: To investigate the phenotype and age-related penetrance of primary open-angle glaucoma (POAG) in Australian families with the myocilin mutation Thr377Met. METHOD AND DESIGN: Cross-sectional genetic study. Four unrelated pedigrees carrying the Thr377Met mutation were ascertained from more than 2000 consecutive cases of POAG in the Glaucoma Inheritance Study in Tasmania and from families with glaucoma referred to the study from throughout Australia. Index cases and available family members were examined for signs of glaucoma, and the presence of the GLC1A Thr377Met mutation was ascertained by single-strand conformation polymorphism analysis and subsequent direct sequencing. RESULTS: From the 4 pedigrees carrying the Thr377Met mutation, 23 individuals with either ocular hypertension (OHT) or POAG were found, with a mean +/- SD age at diagnosis of 41.2 +/- 11.5 years, and a mean peak intraocular pressure of 31.7 +/- 9.9 mm Hg. A further 9 mutation carriers older than 18 years were studied who as yet showed no signs of OHT or POAG (6 of these 9 were younger than 30 years). A single individual with POAG was identified who did not carry the Thr377Met mutation. For Thr377Met carriers, age-related penetrance for OHT or POAG was 88% at age 30 years. A positive family history of POAG was present for 3 of the 4 index cases. Thirteen (57%) of the 23 Thr377Met carriers with OHT or POAG had undergone glaucoma drainage surgery. Although the glaucoma in these families appears to be pressure dependent, 2 individuals showed optic disc cupping before detected elevation in intraocular pressure. One family was of British origin, with a different background haplotype from the other 3 families from Greece or Macedonia, who shared a common haplotype. CONCLUSIONS: The GLC1A Thr377Met mutation is associated with POAG that, in the pedigrees studied, had a younger age at onset and higher peak intraocular pressure than in pedigrees with the more common Gln368STOP mutation. In addition, patients with glaucoma with the Thr377Met mutation were more likely to have undergone glaucoma drainage surgery.

Adult↗
PubMed2003

A family with Axenfeld-Rieger syndrome and Peters Anomaly caused by a point mutation (Phe112Ser) in the FOXC1 gene.

PURPOSE: Mutations of the forkhead transcription factor gene FOXC1 result in anterior segment anomalies. No description of the spectrum of defects resulting from a single point mutation of this gene exists in the ophthalmology literature. We have screened all available patients with Axenfeld-Rieger genes (PITX2 and FOXC1). In this report, we clinically characterize the spectrum of ocular and systemic manifestations in one family resulting from a previously reported point mutation (Phe112Ser) in FOXC1. DESIGN: Observational case series. METHODS: Ten members of a multigenerational family were examined for signs of glaucoma, anterior segment abnormalities, and systemic features of Axenfeld-Rieger syndrome. The examinations were performed in an ophthalmology examination room or in the patients' homes. Blood was obtained from 10 members and screened for mutations in FOXC1 using direct DNA sequencing. RESULTS: A single mutation causing a T to C change in codon 112 (Phe112Ser) of FOXC1 was present in six members of the family. Five of these six patients were examined and all demonstrated anterior segment anomalies. One patient had Axenfeld anomaly, one had Rieger syndrome, and one had both Axenfeld anomaly and Peters anomaly. Additionally, some members demonstrated cardiac abnormalities, which may be secondary to their FOXC1 mutation. CONCLUSIONS: A wide spectrum of clinical phenotypes can result from a single point mutation of FOXC1. This report confirms that Rieger syndrome (with dental and facial abnormalities) can be caused by a mutation in FOXC1. It is also the first report of Peters anomaly being caused by a FOXC1 mutation.

Abnormalities, Multiple↗