GENOMICS 39, 348–358 (1997) ARTICLE NO. GE964491 Recombinational and Physical Mapping of the Locusfor Primary Open-Angle Glaucoma (GLC1A) on Chromosome 1q23–q25 AHM ED B ELM OUDEN,* ,1 M ARIE F. ADAM ,* ,1 S TE ´ PHANE DUPONT DE DINECHIN,* ANTOINE P. BRE ´ ZIN,* P HILIPPE R IGAULT,† ILYA C HUMAKOV,† J EAN-F RANC ¸OIS B ACH,* AND HENRI-J EAN GARCHON* ,2 * INSERM U25, Ho ˆpital Necker, 161, rue de Se `vres, and Institut Necker, 75743 Paris cedex 15, France; and †CEPH, 27 rue Juliette Dodu, 75010 Paris, France Received May 21, 1996; accepted October 15, 1996 The molecular basis of POAG is not known. The in- Primary open-angle glaucoma (POAG) is a leading creased frequency of POAG among relatives of POAG cause of irreversible blindness in industrialized coun- patients indicates that POAG susceptibility is influ- tries. A locus for juvenile-onset POAG, GLC1A, has enced by genetic factors (Leske, 1983). Although the been mapped to 1q21–q31 in a 9-cM interval. With re- genetics of POAG as a whole are complex, the juvenile combinant haplotypes, we have now reduced the form of POAG (onset before the age of 30) was shown GLC1A interval to a maximum of 3 cM, between the to be inherited in a simple Mendelian, autosomal domi- D1S452/NGA1/D1S210 and NGA5 loci. These loci are 2.8 nant manner (Franc ¸ois, 1966; Johnson et al., 1993). Mb apart on a 4.7-Mb contig that we have completed A locus for juvenile-onset POAG, termed GLC1A, was between the D1S2851 and D1S218 loci and that in- mapped to chromosome 1q21 – q31 (Sheffield et al., cludes 96 YAC clones and 48 STSs. The new GLC1A 1993). Subsequently, three families with both juvenile- interval itself is now covered by 25 YACs, 30 STSs, and onset and early-onset POAG were characterized and 16 restriction enzyme site landmarks. The lack of a linked to GLC1A with a high level of significance, which NotI site suggests that the region has few CpG islands suggested variable expressivity of the GLC1A gene and a low gene content. This is compatible with its (Meyer et al., 1994, 1996; Morissette et al., 1995). predominant cytogenetic location on the 1q24 G-band. Initial work mapped GLC1A to a 25-cM interval, be- Finally, we have excluded important candidate genes, tween D1S194 and D1S191. Subsequent characteriza- including genes coding for three ATPases (ATP1B1, tion of recombinant haplotypes assigned the centro- ATP2B4, ATP1A2), an ion channel (VDAC4), antithrom- meric and telomeric boundaries to D1S445 and bine III (AT3), and prostaglandin synthase (PTGS2). D1S218, respectively (Richards et al., 1994; Morissette Our results provide a basis to identify the GLC1A gene. et al., 1995; Johnson et al., 1996), currently leaving a  1997 Academic Press 9-cM interval. In the present study, we have character- ized additional recombinant haplotypes that substan- INTRODUCTION tially reduce the GLC1A-containing interval. We have completed a 4.7-Mb YAC contig covering the GLC1A Primary open-angle glaucoma (POAG) is one of the region, and we have physically mapped the GLC1A most prevalent causes of irreversible blindness in de- gene to a maximum 3-Mb region. Finally, we have ex- veloped countries (Leske, 1983). Its definition associ- cluded important candidate genes. ates a characteristic cupping of the optic disk and an alteration of the visual field (Quigley, 1993). Elevation MATERIALS AND METHODS of intraocular pressure (IOP) is often present and is a major risk factor (Quigley, 1993; Kaufman and Mittag, PCR amplification. Primer sequences of published markers used 1994), although it is not strictly a diagnostic criterion in this work (D1S2851, D1S452, D1S210, WI10286, D1S2351, of POAG. The disease is painless, progresses slowly, NIB1475, NIB1951, D1S2815, D1S1619, D1S2496, AFM107yg1, and is often diagnosed at a late stage, when visual field D1S2450, D1S2177, WI7792, D1S3439, D1S2814, AFM154xc9, defects are severe. Identification of POAG patients at D1S1589, D1S242, D1S218) were available from the Ge ´ne ´thon and the Whitehead Institute/MIT Center for Genome Research (WICGR) an early stage when treatment can still prevent irre- databases. However, to improve PCR efficiency or to obtain PCR versible glaucomatous optic nerve atrophy is therefore products of convenient size, primers for the following markers were essential (Kass et al., 1989). modified: WI10286, AFM107yg1, D1S1589, D1S242, D1S2851, and D1S2814. For these markers and for the newly developed STSs and STRs, primer sequences, amplification product sizes, and PCR condi- 1 These authors have equally contributed to this work. 2 To whom correspondence should be addressed. Fax: 33 1 43 06 tions are listed in Tables 1 and 2. Human genomic DNA and YAC DNA, both isolated with standard procedures, and chromosome 1 / 23 88. E-mail: garchon@necker.fr. 348 0888-7543/97 $25.00 Copyright  1997 by Academic Press All rights of reproduction in any form reserved.