Disease relevance of NNO1

• Autosomal dominant nanophthalmos (NNO1) with high hyperopia and angle-closure glaucoma maps to chromosome 11 [1].
• Nanophthalmos is an uncommon developmental ocular disorder characterized by a small eye, as indicated by short axial length, high hyperopia (severe farsightedness), high lens/eye volume ratio, and a high incidence of angle-closure glaucoma [1].
• A review of published reports also suggests that simple, partial, posterior, pure microphthalmos and nanophthalmos are similar clinical entities sharing total axial length and vitreous cavity length reduction [2].
• PARTICIPANTS: Ten eyes (five primary open-angle glaucoma, four chronic angle-closure glaucoma, one nanophthalmos) of nine patients with a mean age of 68.5+/-12.0 years (range, 43-83 years) [3].
• CONCLUSIONS: Strabismus in nanophthalmos usually manifests as nonaccommodative and partially refractive esotropia [4].

High impact information on NNO1

• We have mapped recessive nanophthalmos to a unique locus at 11q23.3 and identified four independent mutations in MFRP, a gene that is selectively expressed in the eye and encodes a protein with homology to Tolloid proteases and the Wnt-binding domain of the Frizzled transmembrane receptors [5].
• Nanophthalmos is a rare disorder of eye development characterized by extreme hyperopia (farsightedness), with refractive error in the range of +8.00 to +25.00 diopters [5].
• Linkage analysis of a genome scan demonstrated highly significant evidence that nanophthalmos in this family is the result of a defect in a previously unidentified locus (NNO1) on chromosome 11 [1].
• NNO1 is the first human locus associated with nanophthalmos or with an angle-closure glaucoma phenotype, and the identification of the NNO1 locus is the first step toward the cloning of the gene [1].
• Mutations of VMD2 splicing regulators cause nanophthalmos and autosomal dominant vitreoretinochoroidopathy (ADVIRC) [6].

Biological context of NNO1

• METHODS: The records of consecutive patients with nanophthalmos who had cataract surgery from 1978 through 2002 were reviewed for ocular diagnoses, corneal diameter, keratometry, axial length, retinal-choroidal-scleral thickness determined by echography, ocular surgeries, visual acuity, and complications [7].
• The small family size militates against achieving a LOD score of 3, but the haplotype data and the position of the putative MRCS locus within a known nanophthalmos locus are suggestive of linkage [8].

Anatomical context of NNO1

• The modified glycosaminoglycan metabolism in scleral cells may be related to the abnormal packing of collagen bundles, which may in turn contribute to the thickening of sclera and the formation of nanophthalmos [9].
• Three brothers were found to have nanophthalmos as evidenced by marked hyperopia, decreased global axial length, and shallow anterior chambers [10].
• CONCLUSIONS: Visual loss may be secondary to the complications of nanophthalmos, RP, or optic nerve drusen [11].
• Diffusely thickened choroid was detected ultrasonically in 207 eyes in various conditions, including: following intraocular surgery (108 eyes), trauma (8 eyes), phthisis bulbi (52 eyes), endophthalmitis (12 eyes), and nanophthalmos (27 eyes) [12].

Associations of NNO1 with chemical compounds

• CONCLUSION: The results suggest that increased levels of GAGs, particularly of dermatan sulfate and chondroitin sulfate may contribute to the abnormalities of collagen fibrillogenesis and be closely involved with the pathogenesis of nanophthalmos [13].

Other interactions of NNO1

• The elevated fibronectin level may be related to the development of nanophthalmos [14].
• Retinitis pigmentosa, nanophthalmos, and optic disc drusen: a case report [11].
• CONCLUSIONS: Congenital bilateral nanophthalmos may rarely be associated with pigmentary retinal dystrophy [15].

Analytical, diagnostic and therapeutic context of NNO1

• Scleral tissue from two cases of nanophthalmos was examined by amino acid analysis, light microscopy, histochemistry, and transmission electron microscopy [16].
• Nanophthalmos: ultrasound biomicroscopy and Pentacam assessment of angle structures before and after cataract surgery [17].
• METHODS: Choroidal detachment, secondary angle closure, and nanophthalmos were diagnosed using biomicroscopy, indirect ophthalmoscopy, and echography [18].
• Cataract surgery with primary posterior chamber intraocular lens implantation in nanophthalmos [19].
• A 56-year-old Asian woman with nanophthalmos and cataract in the right eye underwent extracapsular cataract extraction with primary posterior chamber intraocular lens implantation of +31.0 D [19].

References