HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (24) Citing Articles via Google Scholar Google Scholar Articles by Yardley, J. Articles by Black, G. C. M. Search for Related Content PubMed PubMed Citation Articles by Yardley, J. Articles by Black, G. C. M.

Mutations of VMD2 Splicing Regulators Cause Nanophthalmos and Autosomal Dominant Vitreoretinochoroidopathy (ADVIRC)

¹From the Academic Unit of Medical Genetics and Regional Genetics Service, St. Mary’s Hospital, Manchester, United Kingdom; ³Department of Ophthalmology, Ghent University Hospital, Ghent, Belgium; ⁴Centre for Medical Genetics, Ghent University Hospital, Ghent, Belgium; ⁵Department of Ophthalmology, St-Jan General Hospital, Bruges, Belgium; ⁶Institute of Ophthalmology, London, United Kingdom; ⁷Department of Ophthalmic Research, Cole Eye Institute, Cleveland, Ohio; ⁸Department of Medical Genetics, Addenbrookes Hospital, Cambridge, United Kingdom; ⁹Exploration Fonctionelle de la Vision, Centre Hospitalier Régional Universitaire, Hôpital Roger Salengro, Lille Cedex, France; ¹⁰Academic Department of Ophthalmology, Manchester Royal Eye Hospital, Manchester, United Kingdom; ¹¹Centre for Molecular Medicine, University of Manchester, Manchester, United Kingdom.

	Abstract

Top Abstract Methods Results Discussion References

 
PURPOSE. To investigate the genetic basis of autosomal dominant vitreoretinochoroidopathy (ADVIRC), a rare, inherited retinal dystrophy that may be associated with defects of ocular development, including nanophthalmos.

METHODS. A combination of linkage analysis and DNA sequencing in five families was used to identify disease-causing mutations in VMD2. The effect of these mutations on splicing was assessed using a minigene system.

RESULTS. Three pathogenic sequence alterations in VMD2 were identified in five families with nanophthalmos associated with ADVIRC. All sequences showed simultaneous missense substitutions and exon skipping.

CONCLUSIONS. VMD2 encodes bestrophin, a transmembrane protein located at the basolateral membrane of the RPE, that is also mutated in Best macular dystrophy. We support that each heterozygous affected individual produces three bestrophin isoforms consisting of the wild type and two abnormal forms: one containing a missense substitution and the other an in-frame deletion. The data showed that VMD2 mutations caused defects of ocular patterning, supporting the hypothesized role for the RPE, and specifically VMD2, in the normal growth and development of the eye.

A number of inherited retinal disorders are caused by mutations in genes expressed in the RPE. One example, Best disease or vitelliform macular dystrophy (VMD2, MIM 153700), is an autosomal dominant disorder associated with macular visual loss in late adolescence or adulthood caused by mutations in the VMD2 gene.⁴ The gene product, bestrophin, is a 585 amino acid transmembrane protein located at the basolateral membrane of the RPE that acts as an oligomeric chloride channel.⁵ Bestrophin mutations alter chloride ion-related conductance across the RPE cell membrane,^{5 6} and abnormal channel function may explain the abnormal electro-oculogram (EOG) seen in patients with Best disease. Almost all VMD2 sequence alterations in patients with classical Best disease are missense mutations (www.uni-wuerzburg.de/humangenetics/vmd2.html and Ref. ⁷ ).

Autosomal dominant vitreoretinochoroidopathy (ADVIRC) is a rare condition first described by Kaufman et al.⁸ It has characteristic retinal and vitreous findings, in particular a peripheral retinal circumferential hyperpigmented band, punctate white opacities in the retina, vitreous fibrillar condensation, and breakdown of the blood retinal barrier with retinal neovascularization. Since its original description, the condition has been reported several times in families of diverse origin.^{9 10 11} Importantly, EOG abnormalities in a subset of these families suggest that ADVIRC may represent a defect at the level of the RPE.¹² Most recently, Lafaut et al.¹³ reported a three-generation ADVIRC pedigree in which all affected members had the characteristic retinal findings and additionally had ocular developmental abnormalities including nanophthalmos, microcornea, closed angle glaucoma, and congenital cataract.

Using this family for genetic analysis, we established linkage of an ADVIRC phenotype to the pericentromeric region of chromosome 11. The disease locus in another family with a related autosomal dominant phenotype comprising microcornea, rod-cone dystrophy, cataract, and posterior staphyloma (MRCS) also maps to this region.¹⁴ Analysis of these two families, and a further three families with similar developmental eye abnormalities and retinal dystrophy, showed that all affected members had pathogenic alterations that cause simultaneous missense substitutions and exon skipping in VMD2. Until now VMD2 was regarded as a gene that underlies Best disease, a macular dystrophy which leads to loss of vision postdevelopmentally. The data demonstrated that VMD2 mutations also underlie defects of ocular patterning, thereby supporting the hypothesized role for the RPE, and specifically VMD2, in the normal growth and development of the eye.

	Methods

Top Abstract Methods Results Discussion References

 
Linkage Analysis
Genomic DNA from 13 members of Family 1 was amplified for known polymorphic genetic markers. The research followed the tenets of the Declaration of Helsinki and informed consent was obtained from the subjects after explanation of the nature and possible consequences of the study. PCR reactions with Abgene Reddymix Taq (Abgene, Epsom, UK) contained 50 ng genomic DNA in a final volume of 30 µL and was amplified as follows: 95°C for 5 minutes, followed by 30 cycles of 94°C for 30 seconds; x°C for 30 seconds; 72°C for 30 seconds (where x°C is the primer annealing temperature). Final extension was carried out at 72°C for 10 minutes. The PCR product (5 µL) was mixed with 5 µL of formamide loading dye, denatured at 96°C for 5 minutes, and separated on a Sequagel 8 (National Diagnostics, Hessle, UK) denaturing PAGE run at 400 V for 3 hours at 20°C and silver stained using standard methods.

Locations and marker order for chromosomes 5, 11, and 12 were taken from http://genome.ucsc.edu and the Genome Database (www.gdb.org). For linkage analysis, allele frequencies were used from the Genome Database. Two-point Lod scores were calculated using the MLINK package.¹⁵

DNA Sequencing
Primers were designed to amplify all coding exons including 50 to 100 bp of flanking intron sequence of VMD2 (sequence obtained from http://genome.ucsc.edu/; primers available on request). These primers were used initially to amplify genomic DNA from two affected individuals in Family 1 and an unaffected control. After sequencing (see below) and the identification of a possible disease causing mutation, DNA from other family members was amplified to confirm co-segregation. PCR reactions using Abgene Reddymix Taq (Abgene) contained 50 ng genomic DNA in a volume of 30 µL and were cycled as described in the Linkage Analysis section. PCR products were purified using Microcon columns (Millipore, Watford, UK) according to the manufacturer’s instructions.

Standard cycle sequencing reactions using BigDye terminator mix v1.1 (Applied Biosystems, Warrington, UK) contained 3–10 ng purified PCR product in 10 µL and were performed using the forward and reverse primers used for initial amplification. The sequencing reactions were then precipitated, dried, and analyzed on an ABI 3700 capillary sequencer (ABI, Foster City, CA).

The exonic regions of VMD2 were analyzed by sequencing in Families 2 to 5 and by SSCP in 68 unrelated individuals with anterior segment dysgenesis, respectively. The absence of any disease causing mutations from control individuals was confirmed by either single-stranded conformational polymorphism (SSCP) analysis or restriction digest. For SSCP/heteroduplex analysis, 5 µL PCR product was mixed with 5 µL of formamide loading dye, denatured, and separated on an 8% acrylamide/bis-acrylamide gel run at 350 V for 16 hours at 4°C and silver stained using standard methods.¹⁶

Cloning
Primers containing a 5' NdeI site were designed to amplify the exon of interest and to include approximately 250 bp of flanking intron on either side. Amplification of genomic DNA from affected individuals was carried out by PCR with Abgene Reddymix HiFidelity Taq (Abgene) containing 40 ng genomic DNA in 20 µL. PCR reaction products were cloned into the TA cloning vector pCRII (Invitrogen, Paisley, UK) as per the manufacturer’s instructions. Clones carrying either the mutant or wild-type allele were identified by direct sequencing. Both wild-type and mutant alleles were subcloned as NdeI fragments into a modified version of the -globin-fibronectin-EDB minigene as described previously.¹⁷

Expression of Minigene
Plasmid (0.4 µg) was transfected into lens cell line CRL-11421 and into human embryological kidney CRL-1573 cells (ATCC, Teddington, UK) using Effectene transfection reagent (Qiagen, Crawley, UK) as per the manufacturer’s instructions. Cells were seeded at 2 x 10⁵ per well in 6-well plates 24 hours before transfection. Twenty-four hours after transfection, total RNA was extracted from cells using Trizol reagent (Invitrogen) according to the manufacturer’s instructions. RT-PCR reactions were performed using the One-Step RT-PCR system (Invitrogen) according to the manufacturer’s instructions with minigene-specific primers or a combination of minigene- and VMD2-specific primers. PCR products were analyzed by agarose gel electrophoresis.

	Results

Top Abstract Methods Results Discussion References

 
Clinical Details
The five families under study all had autosomal dominant developmental eye abnormalities (including nanophthalmos, microcornea, closed angle glaucoma, and congenital cataract) associated with retinal dystrophy (Fig. 1) . Families 1, 2, and 3 have been previously described.^{13 14 18} In all five families the retinal dystrophy was characteristic of ADVIRC with circumferential peripheral retinal hyperpigmentation, punctate retinal and vitreous opacities, and choroidal atrophy. Individuals from all families had abnormal electro-retinograms (ERG), suggestive of a more widespread photoreceptor dysfunction. Family 2 had a more severe retinal phenotype including rod–cone dystrophy and posterior staphyloma. Affected individuals in all families had pathologically low EOGs.

View larger version (85K): [in this window] [in a new window]   FIGURE 1. Clinical features of developmental phenotypes caused by mutation in VMD2. (A) Microcornea in individual VI3 of Family 3. The horizontal corneal diameter demonstrated is 9.5 mm. (B) Posterior subcapsular cataract in individual III6 of Family 1. (C) Fundal photomontage of individual VI2 of Family 3. (D, E) Pedigrees of Family 1 and 3, respectively.

View larger version (20K): [in this window] [in a new window]   FIGURE 2. Genetic analysis of ADVIRC family 1 demonstrating haplotypes for markers from pericentric region of chromosome 11. Disease haplotype is indicated by black line. Multiple informative recombination events in individuals IV-1 and III-6 delineate a critical region flanked by markers D11S4152 and D11S4139.

Sequencing of the VMD2 coding sequence in Family 1 (of Belgian origin) revealed a missense change resulting in the substitution of valine by methionine at codon 86 in exon 4 (c.256G>A, p.V86M; Fig. 3 ). Subsequent analysis of all VMD2 exons and introns in Families 2 to 5 revealed disease-causing sequence alterations in each (Fig. 3) . The V86M substitution was also found in Family 3 (from NE France),¹⁸ and Family 4, (from Belgium, unpublished). Analysis with two intragenic microsatellite markers was consistent with this being a single ancestral mutational event in all three families (data not shown). Sequencing of affected individuals from Family 2 revealed an adenine to guanosine substitution at position 715 in exon 7 (c.715G>A, p.V239M) and a guanosine to adenine substitution at position 707 in exon 6 (c.707A>G, p.Y236C) in Family 5. All three sequence alterations fully co-segregated with all affected family members and were not present in 400 normal control chromosomes. Screening of VMD2 in 18 unrelated individuals with microphthalmia/coloboma and 50 individuals with various forms of anterior segment dysgenesis revealed no pathogenic alterations.

View larger version (23K): [in this window] [in a new window]   FIGURE 3. Ideogram showing effects of exon 4 and 7 mutations of VMD2. Exon 4 mutation on left (Families 1, 3, and 4), exon 7 mutation on right (Family 2). Sequence electropherograms showing wild-type (left) and mutant (right) sequences. Mutant sequences are shown in heterozygous state. For exon 7, reverse sequence is shown. Mutation results in the predicted expression of two protein isoforms, one containing a missense mutation, the other resulting in an in-frame deletion. The region of VMD2 deleted is shown in black by a modeled diagram of VMD2 (after Sun et al.5 ).

View larger version (30K): [in this window] [in a new window]   FIGURE 4. In vitro splicing assay using minigene constructs containing wild-type and mutant VMD2 exons. Wild-type and mutant forms of exons 4 and 7 were cloned into a minigene vector and transfected into mammalian cells.17 After extraction, RNA was reverse-transcribed to assay the effects of VMD2 mutations on splicing. (i) Diagram of splicing assay construct showing position of primers used for PCR. (ii) Splicing analysis of VMD2 exon 4 G256A mutation. PCR used vector-specific primers (a) and (b). Lane 1: molecular marker; Lane 2: control minigene without VMD2 exon shows amplification of 286 bp band corresponding to spliced vector exons; Lane 3: minigene containing wild-type exon 4. The 530 bp band corresponds to normally spliced VMD2 exon 4; Lane 4: minigene containing exon 4 with G256A mutation. In addition to 530 bp band, there is now a small proportion of the 286 bp band (corresponding to skipping of VMD2 exon 4) and two additional bands which sequencing corresponded to splice-forms using alternative upstream splice sites present in the minigene construct. RT-PCR using GAPDH was used to normalize the reactions. (iii) Splicing analysis of VMD2 exon 7 G715A mutation. PCR used vector-specific primer (a) and VMD2-specific primer (c). Lane 1: molecular marker; Lane 2: control minigene without VMD2 exon; Lane 3: minigene containing wild-type exon 7. Band of 206 bp corresponds to normally spliced VMD2 exon 7; Lane 4: minigene containing exon 7 with G715A mutation. There is only a very low level of the 206 bp band, suggesting that the mutation severely disrupts splicing. As in (ii), there are additional bands corresponding to splice-forms using alternative upstream splice sites present in the minigene construct but not in human genomic DNA. Lane 5: minigene containing Best-disease causing mutation G727A. Band of 206 bp corresponds to normally spliced VMD2 exon.

	Discussion

Top Abstract Methods Results Discussion References

These data suggested that each heterozygous affected individual produces three bestrophin isoforms. In addition to the product of the wild-type allele, each mutant allele is capable of producing two abnormal proteins, one containing a missense substitution, the other an in-frame deletion. The different phenotypes, which in Family 2 was more severe than in the other families, are likely to relate the different properties and proportions of the two mutant (i.e., substituted and truncated) isoforms. A similar mechanism was proposed by Zenker et al.²¹ for a patient with dual phenotypes (periventricular nodular heterotopia and frontometaphyseal dysplasia) that are presumed to result from the presence of dual isoforms of filamin a (FLNA) that are both produced by a de novo mutation which results in both exon skipping and a missense substitution. The illustration that a pathogenic missense mutation may also alter the regulation of splicing is likely to be a widely applicable disease mechanism for other disorders. It is likely that other missense substitutions within exons, in particular those altering exonic splicing regulatory elements, will also specific phenotypic consequences.

Ninety of 93 identified VMD2 mutations in patients with classical Best disease are missense mutations or small in-frame deletions (www.uni-wuerzburg.de/humangenetics/vmd2.html and Ref. ⁷ ). The others consist of a splice site mutation and two frameshift mutations, one of which affects the extreme C terminus of the protein. One patient who is homozygous for the mutation W93C had a phenotype consistent with Best disease.^{4 22} However, haploinsufficiency may result in a different phenotype. Since bestrophin acts as an oligomer,⁵ there is scope for dominant negative effects. We suggest that the abnormally spliced products described here have a novel deleterious effect on ocular development. Since individuals in all four families had clinical and developmental features of nanophthalmos, this suggests that a mutation of VMD2 could also underlie the original NNO1 family which has been mapped to a critical region encompassing the gene.¹⁹

The RPE is critical to ocular patterning, and its early ablation leads to arrest of eye growth and subsequent resorption of all ocular structures.¹ Within the eye VMD2 is expressed in both developing and adult RPE.^{4 23} Although the mechanism underlying the developmental defects in the families presented here remains to be elucidated, our data support the hypothesized role for the RPE in ocular growth. Interestingly, the MITF transcription factor that is crucial for RPE differentiation and maintenance, and that is mutated in the microphthalmia mouse, regulates the expression of VMD2.²⁴ The maintenance and health of the RPE is central to photoreceptor maintenance and to the pathogenesis of AMD, a disease that shares several characteristics with Best disease. It is unknown why patients with these mutations have evidence of a predominantly peripheral retinal phenotype and generalized photoreceptor cell death (as witnessed by the intraretinal pigment and abnormal ERGs), while patients with Best disease have cell death confined to the macular region. Until now, VMD2 has been regarded as the gene that underlies Best disease, a macular dystrophy that leads to loss of vision later in life. The observed defects of ocular growth (nanophthalmos) as a result of mutations in VMD2 therefore potentially demonstrate a common etiology for pathologic processes of development and of later-onset (macular dystrophy).

Many genes underlying ocular developmental disorders also encode proteins expressed postdevelopmentally, for example, microphthalmia (SOX2, CHX10, MITF),^{2 25 26} anterior segment dysgenesis (MAF, PITX2),^{27 28} glaucoma (LMX1B, MYOC),^{29 30} and congenital cataract (PITX3, PAX6).^{31 32} In the case of both MAF and PAX6, pathogenic mutations are known to cause both congenital (cataract and aniridia, respectively) and late-onset (progressive cortical cataract and keratitis, respectively) phenotypes in the same individuals.³³ Such proteins have important roles in both the development and maintenance of mature tissues. In the context of identifying candidates for multifactorial late-onset disorders, our data suggest that the distinction between ‘developmental’ and ‘late-onset’ genes is artificial and that developmental genes with appropriate tissue expression should be considered as candidate genes for late-onset disorders.

Electronic Database Information
VMD2 sequence alterations: www.uni-wuerzburg.de/humangenetics/vmd2.html. Locations and marker order for chromosomes University of California Santa Cruz (http://genome.ucsc.edu) and the Genome Database (www.gdb.org). ESEFinder program (http://exon.cshl.org/ESE/index.html).

	Footnotes

 
² These authors contributed equally to the work presented here and should be regarded as equivalent senior authors.

Supported by Grant GR067443AIA from the Wellcome Trust (RP, JY). GCMB is a Wellcome Trust Senior Research Fellow in Clinical Science.

Submitted for publication May 18, 2004; accepted June 28, 2004.

Disclosure: J. Yardley, None; B.P. Leroy, None; N. Hart-Holden, None; B.A. Lafaut, None; B. Loeys, None; L.M. Messiaen, None; R. Perveen, None; M.A. Reddy, None; S.S. Bhattacharya, None; E. Traboulsi, None; D. Baralle, None; J.-J. De Laey, None; B. Puech, None; P. Kestelyn, None; A.T. Moore, None; F.D.C. Manson, None; G.C.M. Black, None

The publication costs of this article were defrayed in part by page charge payment. This article must therefore be marked "advertisement" in accordance with 18 U.S.C. 1734 solely to indicate this fact.

Corresponding author: Graeme C. M. Black, Department of Clinical Genetics, St Mary’s Hospital, Hathersage Road, Manchester M13 0JH, UK; gblack{at}man.ac.uk.

	References

Top Abstract Methods Results Discussion References

 

1. Raymond SM, Jackson IJ. The retinal pigmented epithelium is required for development and maintenance of the mouse neural retina. Curr Biol. 1995;5:1286–1295.[CrossRef][ISI][Medline][Order article via Infotrieve]
2. Steingrimsson E, Moore KJ, Lamoreux ML, et al. Molecular basis of mouse microphthalmia (mi) mutations helps explain their developmental and phenotypic consequences. Nat Genet. 1994;8:256–263.[CrossRef][ISI][Medline][Order article via Infotrieve]
3. Boulton M, Dayhaw-Barker P. The role of the retinal pigment epithelium: topographical variation and ageing changes. Eye. 2001;15:384–389.[ISI][Medline][Order article via Infotrieve]
4. Petrukhin K, Koisti MJ, Bakall B, et al. Identification of the gene responsible for Best macular dystrophy. Nat Genet. 1998;19:241–247.[CrossRef][ISI][Medline][Order article via Infotrieve]
5. Sun H, Tsunenari T, Yau KW, et al. The vitelliform macular dystrophy protein defines a new family of chloride channels. Proc Natl Acad Sci. 2002;19:4008–4013.
6. Tsunenari T, Sun H, Williams J, et al. Structure-function analysis of the bestrophin family of anion channels. J Biol Chem. 2003;278:41114–41125.[Abstract/Free Full Text]
7. Kramer F, Mohr N, Kellner U, et al. Ten novel mutations in VMD2 associated with Best macular dystrophy (BMD). Hum Mutation. 2003;22:418–424.[Medline][Order article via Infotrieve]
8. Kaufman SJ, Goldberg MF, Orth DH, et al. Autosomal dominant vitreoretinochoroidopathy. Arch Ophthalmol. 1982;100:272–278.[Abstract]
9. Blair NP, Goldberg MF, Fishman GA, et al. Autosomal dominant vitreoretinochoroidopathy (ADVIRC). Br J Ophthalmol. 1984;68:2–9.[Abstract/Free Full Text]
10. Traboulsi EI, Payne JW. Autosomal dominant vitreoretinochoroidopathy. Report of the third family. Arch Ophthalmol. 1993;111:194–196.[Abstract]
11. Goldberg MF, Lee FL, Tso MO, et al. Histopathologic study of autosomal dominant vitreoretinochoroidopathy. Peripheral annular pigmentary dystrophy of the retina. Ophthalmology. 1989;96:1736–1746.[ISI][Medline][Order article via Infotrieve]
12. Han DP, Lewandowski MF. Electro-oculography in autosomal dominant vitreoretinochoroidopathy. Arch Ophthalmol. 1992;110:1563–1567.[Abstract]
13. Lafaut BA, Loeys B, Leroy BP, et al. Clinical and electrophysiological findings in autosomal dominant vitreoretinochoroidopathy: report of a new pedigree. Graefes Arch Clin Exp Ophthalmol. 2001;239:575–582.[ISI][Medline][Order article via Infotrieve]
14. Reddy MA, Francis PJ, Berry V, et al. A clinical and molecular genetic study of a rare dominantly inherited syndrome (MRCS) comprising of microcornea, rod-cone dystrophy, cataract, and posterior staphyloma. Br J Ophthalmol. 2003;87:197–202.[Abstract/Free Full Text]
15. Lathrop GM, Lalouel JM, Julier C, et al. Strategies for multilocus linkage analysis in humans. Proc Natl Acad Sci USA. 1984;81:3443–3446.[Abstract/Free Full Text]
16. Sambrook J, Russell D. Molecular cloning. A laboratory manual. 2000; 3^rd ed. Cold Spring Harbor Laboratory Press New York.
17. Baralle M, Baralle D, De Conti L, et al. Identification of a mutation that perturbs NF1 gene splicing using genomic DNA samples and a minigene assay. J Med. Genet. 2003;40:220–222.[Free Full Text]
18. François P, Puech B, Hache JC, et al. Hérédo-dystrophie choriorétinovitréenne, microcornée, glaucome et cataracte. J Fr Ophtalmol. 1993;16:129–140.[ISI][Medline][Order article via Infotrieve]
19. Othman MI, Sullivan SA, Skuta GL, et al. Autosomal dominant nanophthalmos (NNO1) with high hyperopia and angle-closure glaucoma maps to chromosome 11. Am J Hum Genet. 1998;63:1411–1418.[CrossRef][ISI][Medline][Order article via Infotrieve]
20. Cartegni L, Wang J, Zhu Z, et al. ESEfinder: A web resource to identify exonic splicing enhancers. Nucleic Acids Res. 2003;31:3568–3571.[Abstract/Free Full Text]
21. Zenker M, Rauch A, Winterpacht A, et al. Dual phenotype of periventricular nodular heterotopia and frontometaphyseal dysplasia in one patient caused by a single FLNA mutation leading to two functionally different aberrant transcripts. Am J Hum Genet. 2004;74:731–737.[CrossRef][ISI][Medline][Order article via Infotrieve]
22. Nordström S, Thorburn W. Dominantly inherited macular degeneration (Best’s disease) in a homozygous father with 11 children. Clin Genet. 1980;18:211–221.[ISI][Medline][Order article via Infotrieve]
23. Bakall B, Marmorstein LY, Hoppe G, et al. Expression and localization of bestrophin during normal mouse development. Invest Ophthalmol Vis Sci. 2003;44:3622–3628.[Abstract/Free Full Text]
24. Esumi N, Oshima Y, Li Y, Campochiaro PA, Zack DJ. Analysis of the VMD2 promoter and implication of E-box binding factors in its regulation. J Biol Chem. 2004;30;279:19064–19073.
25. Fantes J, Ragge NK, Lynch SA, et al. Mutations in SOX2 cause anophthalmia. Nat Genet. 2003;33:461–463.[CrossRef][ISI][Medline][Order article via Infotrieve]
26. Percin EF, Ploder LA, Yu JJ, et al. Human microphthalmia associated with mutations in the retinal homeobox gene CHX10. Nat Genet. 2000;25:397–401.[CrossRef][ISI][Medline][Order article via Infotrieve]
27. Jamieson RV, Perveen R, Kerr B, et al. Domain disruption and mutation of the bZIP transcription factor, MAF, associated with cataract, ocular anterior segment dysgenesis and coloboma. Hum Mol Genet. 2002;11:33–42.[Abstract/Free Full Text]
28. Semina EV, Reiter R, Leysens NJ, et al. Cloning and characterization of a novel bicoid-related homeobox transcription factor gene, RIEG, involved in Rieger syndrome. Nat Genet. 1998;14:392–399.
29. Dreyer SD, Zhou G, Baldini A, et al. Mutations in LMX1B cause abnormal skeletal patterning and renal dysplasia in nail patella syndrome. Nat Genet. 1998;19:47–50.[CrossRef][ISI][Medline][Order article via Infotrieve]
30. Stone EM, Fingert JH, Alward WL, et al. Identification of a gene that causes primary open angle glaucoma. Science. 1997;275:668–670.[Abstract/Free Full Text]
31. Hanson IM, Fletcher JM, Jordan T, et al. Mutations at the PAX6 locus are found in heterogeneous anterior segment malformations including Peters’ anomaly. Nat Genet. 1994;6:168–173.[CrossRef][ISI][Medline][Order article via Infotrieve]
32. Semina EV, Ferrell RE, Mintz-Hittner HA, et al. A novel homeobox gene PITX3 is mutated in families with autosomal-dominant cataracts and ASMD. Nat Genet. 1996;19:167–170.
33. Jamieson RV, Munier F, Balmer A, et al. Pulverulent cataract with variably associated microcornea and iris coloboma in a MAF mutation family. Br J Ophthalmol. 2003;87:411–412.[Abstract/Free Full Text]

This article has been cited by other articles:

				K. Yu, Q. Xiao, G. Cui, A. Lee, and H. C. Hartzell The Best Disease-Linked Cl- Channel hBest1 Regulates CaV1 (L-type) Ca2+ Channels via src-Homology-Binding Domains J. Neurosci., May 28, 2008; 28(22): 5660 - 5670. [Abstract] [Full Text] [PDF]

				H. C. Hartzell, Z. Qu, K. Yu, Q. Xiao, and L.-T. Chien Molecular Physiology of Bestrophins: Multifunctional Membrane Proteins Linked to Best Disease and Other Retinopathies Physiol Rev, April 1, 2008; 88(2): 639 - 672. [Abstract] [Full Text] [PDF]

				L. Eksandh, G. Adamus, L. Mosgrove, and S. Andreasson Autoantibodies Against Bestrophin in a Patient With Vitelliform Paraneoplastic Retinopathy and a Metastatic Choroidal Malignant Melanoma Arch Ophthalmol, March 1, 2008; 126(3): 432 - 435. [Full Text] [PDF]

				L.-T. Chien and H. C. Hartzell Drosophila Bestrophin-1 Chloride Current Is Dually Regulated by Calcium and Cell Volume J. Gen. Physiol., October 29, 2007; 130(5): 513 - 524. [Abstract] [Full Text] [PDF]

				K. Yu, Z. Qu, Y. Cui, and H. C. Hartzell Chloride Channel Activity of Bestrophin Mutants Associated with Mild or Late-Onset Macular Degeneration Invest. Ophthalmol. Vis. Sci., October 1, 2007; 48(10): 4694 - 4705. [Abstract] [Full Text] [PDF]

				R. F. Mullins, M. H. Kuehn, E. A. Faidley, N. A. Syed, and E. M. Stone Differential Macular and Peripheral Expression of Bestrophin in Human Eyes and Its Implication for Best Disease Invest. Ophthalmol. Vis. Sci., July 1, 2007; 48(7): 3372 - 3380. [Abstract] [Full Text] [PDF]

				N. Esumi, S. Kachi, P. A. Campochiaro, and D. J. Zack VMD2 Promoter Requires Two Proximal E-box Sites for Its Activity in Vivo and Is Regulated by the MITF-TFE Family J. Biol. Chem., January 19, 2007; 282(3): 1838 - 1850. [Abstract] [Full Text] [PDF]

				V. M. Milenkovic, A. Rivera, F. Horling, and B. H. F. Weber Insertion and Topology of Normal and Mutant Bestrophin-1 in the Endoplasmic Reticulum Membrane J. Biol. Chem., January 12, 2007; 282(2): 1313 - 1321. [Abstract] [Full Text] [PDF]

				J. L. Wiggs Genetic Etiologies of Glaucoma Arch Ophthalmol, January 1, 2007; 125(1): 30 - 37. [Abstract] [Full Text] [PDF]

				K. Yu, Y. Cui, and H. C. Hartzell The Bestrophin Mutation A243V, Linked to Adult-Onset Vitelliform Macular Dystrophy, Impairs Its Chloride Channel Function Invest. Ophthalmol. Vis. Sci., November 1, 2006; 47(11): 4956 - 4961. [Abstract] [Full Text] [PDF]

				L.-T. Chien, Z.-R. Zhang, and H. C. Hartzell Single Cl- Channels Activated by Ca2+ in Drosophila S2 Cells Are Mediated By Bestrophins J. Gen. Physiol., August 28, 2006; 128(3): 247 - 259. [Abstract] [Full Text] [PDF]

				Z. Qu, L.-T. Chien, Y. Cui, and H. C. Hartzell The anion-selective pore of the bestrophins, a family of chloride channels associated with retinal degeneration. J. Neurosci., May 17, 2006; 26(20): 5411 - 5419. [Abstract] [Full Text] [PDF]

				L. Y. Marmorstein, J. Wu, P. McLaughlin, J. Yocom, M. O. Karl, R. Neussert, S. Wimmers, J. B. Stanton, R. G. Gregg, O. Strauss, et al. The Light Peak of the Electroretinogram Is Dependent on Voltage-gated Calcium Channels and Antagonized by Bestrophin (Best-1) J. Gen. Physiol., April 24, 2006; 127(5): 577 - 589. [Abstract] [Full Text] [PDF]

				C. Hartzell, Z. Qu, I. Putzier, L. Artinian, L.-T. Chien, and Y. Cui Looking Chloride Channels Straight in the Eye: Bestrophins, Lipofuscinosis, and Retinal Degeneration Physiology, October 1, 2005; 20(5): 292 - 302. [Abstract] [Full Text] [PDF]

				O. H. Sundin, G. S. Leppert, E. D. Silva, J.-M. Yang, S. Dharmaraj, I. H. Maumenee, L. C. Santos, C. F. Parsa, E. I. Traboulsi, K. W. Broman, et al. Extreme hyperopia is the result of null mutations in MFRP, which encodes a Frizzled-related protein PNAS, July 5, 2005; 102(27): 9553 - 9558. [Abstract] [Full Text] [PDF]

This Article Abstract Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (24) Citing Articles via Google Scholar Google Scholar Articles by Yardley, J. Articles by Black, G. C. M. Search for Related Content PubMed PubMed Citation Articles by Yardley, J. Articles by Black, G. C. M.