Volume 1 (2017): Issue s1 (October 2017)
EBTNA Utility Gene Test on Ophthalmology

Inherited eye diseases are a group of conditions with genetic and phenotypic heterogeneity. Advances in ocular genetic research have provided insights into the genetic basis of many eye diseases. Genetic and technological progress is improving the management and care of patients with inherited eye diseases. Diagnostic laboratories continue to develop strategies with high specificity and sensitivity that reduce the costs and time required for genetic testing. The introduction of next generation sequencing technologies has significantly advanced the identification of new gene candidates and has expanded the scope of genetic testing. Gene therapy offers an important opportunity to target causative genetic mutations. There are clinical trials of treatments involving vector-based eye gene therapies, and a significant number of loci and genes now have a role in the diagnosis and treatment of human eye diseases. Applied genetic technology heralds the development of individualized treatments, ushering ophthalmology into the field of personalized medicine. Many therapeutic strategies have demonstrated efficacy in preclinical studies and have entered the clinical trial phase. In this paper we review the topic of genetic testing in inherited eye diseases. We provide some background information about genetic counseling and genetic testing in ophthalmology and discuss how genetic testing can be helpful to patients and families with inherited eye diseases.

The main constituents of the genus Sideritis are various terpenoids, sterols, coumarins, flavonoid aglycones and glycosides. Sideritis species have been traditionally used as infusions or flavoring agents and in medicine as anti-inflammatory, antiulcer, antimicrobial, antioxidant, antispasmodic and analgesic agents. This paper includes the following sections: Introduction, Description and distribution of Sideritis spp, Pharmacological effects, Toxicity tests, Rationale for use of Sideritis spp. in ophthalmology and Conclusions. The aim is to provide a comprehensive overview on the botanical, phytochemical and pharmacological aspects of the genus Sideritis, and to establish the scientific basis of its pharmacological use. New approaches to using officinal plants have recently yielded significant results. The paper also reviews this information and provides a critical view on the options for exploiting the potential of Sideritis spp. in ophthalmology.

We studied the scientific literature and disease guidelines in order to summarize the clinical utility of genetic testing for achromatopsia. The disease has autosomal recessive inheritance, a prevalence of 1/30000-1/50000, and is caused by mutations in the CNGB3, CNGA3, GNAT2, PDE6C, ATF6 and PDE6H genes. Clinical diagnosis is by ophthalmological examination, color vision testing and electrophysiological testing. Genetic testing is useful for confirming diagnosis and for differential diagnosis, couple risk assessment and access to clinical trials.

We studied the scientific literature and disease guidelines in order to summarize the clinical utility of genetic testing for Bardet- Biedl syndrome (BBS). The disease has autosomal recessive inheritance, a prevalence varying from one in 13 500 to one in 160 000, and is caused by mutations in the ARL6, BBIP1, BBS1, BBS2, BBS4, BBS5, BBS7, BBS9, BBS10, BBS12, CEP290, IFT172, IFT27, LZTFL1, MKKS, MKS1, NPHP1, SDCCAG8, TRIM32, TTC8 and WDPCP genes. The clinical diagnosis of BBS is based on four primary features or three primary features plus two secondary features. The genetic test is useful for confirming diagnosis, and for differential diagnosis, couple risk assessment and access to clinical trials.

We studied the scientific literature and disease guidelines in order to summarize the clinical utility of the genetic test for Best vitelliform macular dystrophy (BVMD). BVMD is mostly inherited in an autosomal dominant manner (autosomal recessive transmission is rare). The overall prevalence is currently unknown. BVMD is caused by mutations in the BEST1 gene. Clinical diagnosis is based on clinical findings, ophthalmological examination, optical coherence tomography, electrooculography and electroretinography. The genetic test is useful for confirming diagnosis, and for differential diagnosis, couple risk assessment and access to clinical trials.

We studied the scientific literature and disease guidelines in order to summarize the clinical utility of the genetic test for Bietti crystalline dystrophy (BCD). The disease has autosomal recessive inheritance, a prevalence of 1 per 67 000, and is caused by mutations in the CYP4V2 gene. Clinical diagnosis is based on clinical findings, ophthalmological examination, electroretinography and optical coherence tomography. The genetic test is useful for confirming diagnosis, and for differential diagnosis, couple risk assessment and access to clinical trials.

We studied the scientific literature and disease guidelines in order to summarize the clinical utility of the genetic test for central areolar choroidal dystrophy (CACD). CACD is mostly inherited in an autosomal dominant manner. Transmission is rarely autosomal recessive. Overall prevalence is currently 1-9 per 100 000. CACD is caused by mutations in the PRPH2 and GUCY2D genes. Clinical diagnosis is based on clinical findings, ophthalmological examination, fluorescein angiography, electroretinography (showing cone dystrophy) and stereo fundus photography. The genetic test is useful for confirming diagnosis, and for differential diagnosis, couple risk assessment and access to clinical trials.

We studied the scientific literature and disease guidelines in order to summarize the clinical utility of the genetic test for choroideremia (CHM). CHM is an inherited X-linked recessive disorder associated with variations in the CHM gene. The overall prevalence of CHM varies from 1 in 50 000 to 1 in 100 000. Clinical diagnosis is based on clinical findings, ophthalmological examination, visual field, fundus autofluorescence, optical coherence tomography and electroretinography. The genetic test is useful for confirming diagnosis and for differential diagnosis, couple risk assessment and access to clinical trials.

We studied the scientific literature and disease guidelines in order to summarize the clinical utility of genetic testing for ocular coloboma (COI). COI is inherited in an autosomal dominant manner associated with variations in the PAX6, ABCB6 and FZD5 genes and in an autosomal recessive manner associated with variations in the SALL2 gene. Overall prevalence is 1 per 100,000 live births. Clinical diagnosis is based on clinical findings, ophthalmogical examination, family history, fundus examination and electroretinography. The genetic test is useful for confirming diagnosis, and for differential diagnosis, couple risk assessment and access to clinical trials.

We studied the scientific literature and disease guidelines in order to summarize the clinical utility of genetic testing for color vision deficiency (CVD). Deuteranopia affects 1 in 12 males and is inherited in an X-linked recessive manner. It is associated with variations in the OPN1LW (OMIM gene: 300822; OMIM disease: 303900) and OPN1MW (OMIM gene: 300821; OMIM disease: 303800) genes. Tritanopia has a prevalence of 1 in 10 000, is inherited in an autosomal dominant manner, and is related to variations in the OPN1SW (OMIM gene: 613522; OMIM disease: 190900) gene. Blue cone monochromatism has a prevalence of 1 in 100 000, is inherited in an X-linked recessive manner and is related to mutations in the OPN1LW (OMIM gene: 300822; OMIM disease: 303700) and OPN1MW (OMIM gene: 300821; OMIM disease: 303700) genes. Clinical diagnosis is based on clinical findings, ophthalmogical examination, family history, electroretingraphy, color vision testing and dark adaptometry. The genetic test is useful for confirming diagnosis, and for differential diagnosis, couple risk assessment and access to clinical trials.

We studied the scientific literature and disease guidelines in order to summarize the clinical utility of the genetic test for cone rod dystrophies (CORDs). CORDs are caused by variations in the ABCA4, ADAM9, AIPL1, C8orf37, CACNA1F, CACNA2D4, CDHR1, CNGA3, CRX, DRAM2, GUCA1A, GUCY2D, HRG4, KCNV2, PDE6C, PITPNM3, POC1B, PROM1, PRPH2, RAB28, RAX2, RIMS1, RPGRIP1, RPGR SEMA4A, TTLL5 genes, with an overall prevalence of 1 per 40 000. Most genes have autosomal recessive inheritance; the others have autosomal dominant or X-linked recessive transmission. Clinical diagnosis is based on clinical findings, color vision testing, ophthalmological examination and electroretinography. The genetic test is useful for confirming diagnosis, and for differential diagnosis, couple risk assessment and access to clinical trials.

We studied the scientific literature and disease guidelines in order to summarize the clinical utility of the genetic test for congenital stationary night blindness (CSNB). CSNB is inherited in an autosomal dominant manner in the case of mutations in the GNAT1, PDE6B and RHO genes, in an autosomal recessive manner in the case of mutations in the CABP4, GNB3, GPR179, GRM6, LRIT3, SAG, SLC24A1, TRPM1 and genes and in an X-linked recessive manner in the case of mutations in the CACNA1F and NYX genes. The overall prevalence of CSNB is not known. Clinical diagnosis is based on clinical findings, ophthalmological examination, visual evoked potentials and electroretinography. The genetic test is useful for confirming diagnosis and for differential diagnosis, couple risk assessment and access to clinical trials.

We studied the scientific literature and disease guidelines in order to summarize the clinical utility of the genetic test for corneal dystrophies and other Mendelian corneal diseases (CDs). CDs are mostly inherited in an autosomal dominant manner (autosomal recessive inheritance is rare). The overall prevalence is currently unknown. CDs are caused by mutations in the AGBL1, CHST6, COL8A2, DCN, GSN, KRT12, KRT3, NLRP1, PAX6, PIKFYVE, PRDM5, SLC4A11, TACSTD2, TCF4, TGFBI, UBIAD1, VSX1, ZEB1, and ZNF469 genes. Clinical diagnosis is based on clinical findings, ophthalmological examination, confocal microscopy and slit-lamp biomicroscopy. The genetic test is useful for confirming diagnosis and for differential diagnosis, couple risk assessment and access to clinical trials.

We studied the scientific literature and disease guidelines in order to summarize the clinical utility of genetic testing for Doyne honeycomb retinal dystrophy (DHRD). The disease has an autosomal dominant inheritance and is caused by variations in the EFEMP1 gene. There is insufficient data to establish the prevalence of DHRD. Clinical diagnosis is based on clinical findings, ophthalmological examination, electroretinography, fluorescein angiography and optical coherence tomography. The genetic test is useful for confirming diagnosis, and for differential diagnosis, couple risk assessment and access to clinical trials.

We studied the scientific literature and disease guidelines in order to summarize the clinical utility of genetic testing for enhanced S-cone syndrome (ESCS). The disease has autosomal recessive inheritance, a prevalence of less than one per million, and is caused by mutations in the NR2E3 gene. Clinical diagnosis is based on clinical findings, ophthalmological examination, electroretinography, color vision testing and optical coherence tomography. The genetic test is useful for confirming diagnosis, and for differential diagnosis, couple risk assessment and access to clinical trials.

We studied the scientific literature and disease guidelines in order to summarize the clinical utility of genetic testing for familial exudative vitreoretinopathy (FEVR). There is insufficient data to determine the prevalence of FEVR. Variations in the FZD4 (OMIM gene: 604579; OMIM disease: 133780), TSPAN12 (OMIM gene: 613138; OMIM disease: 613310) and ZNF408 (OMIM gene: 616454; OMIM disease: 616468) genes have autosomal dominant inheritance, whereas variations in LRP5 (OMIM gene: 603506; OMIM disease: 601813) have autosomal dominant or recessive inheritance and variations in NDP (OMIM gene: 300658; OMIM disease: 305390) have X-linked inheritance. Clinical diagnosis is based on clinical findings, family history, ophthalmological examination, fundoscopy, slit-lamp examination and fluorescein angiography. The genetic test is useful for confirming diagnosis and for differential diagnosis, couple risk assessment and access to clinical trials.

We studied the scientific literature and disease guidelines in order to summarize the clinical utility of genetic testing for gyrate atrophy of the choroid and retina (GACR). GACR is inherited in an autosomal recessive manner, and has a prevalence of 1/50000 in Finland. In the international literature there are approximately 200 biochemically confirmed cases. GACR is caused by mutations in the OAT gene. Clinical diagnosis involves ophthalmological examination, electrophysiological testing (electroretinography - ERG), coherence tomography and assay of ornithine levels in body fluids. The genetic test is useful for confirming diagnosis, as well as for differential diagnosis, couple risk assessment and access to clinical trials.

We studied the scientific literature and disease guidelines in order to summarize the clinical utility of genetic testing for infantile nystagmus (IN). Forms of IN associated with variations in CACNA1F, FRMD7 and GPR143 genes have X-linked recessive inheritance, whereas variations in SLC38A8, TYR and TYRP1 genes have an autosomal recessive inheritance and variations in COL11A1, CRYBA1 and PAX6 genes have an autosomal dominant inheritance. The prevalence of all forms of IN is estimated to be 1 in 5000. Clinical diagnosis is based on clinical findings, age of onset, family history, ophthalmological examination, fundoscopy, electroretinography, optical coherence tomography, slit lamp examination and visual evoked potentials. The genetic test is useful for confirming diagnosis, and for differential diagnosis, couple risk assessment and access to clinical trials.

We studied the scientific literature and disease guidelines in order to summarize the clinical utility of genetic testing for Inherited eye misalignment (IEM). Forms of IEM associated with variations in the SALL4, CHN1, TUBB3 and KIF21A genes have autosomal dominant inheritance, whereas those associated with variations in the ROBO3, PHOX2A, HOXA1 and HOXB1 genes have autosomal recessive inheritance. The prevalence of MS is currently unknown. Diagnosis is based on clinical findings, family history, visual acuity testing and fundus examination. The genetic test is useful for confirming diagnosis, and for differential diagnosis, couple risk assessment and access to clinical trials.

We studied the scientific literature and disease guidelines in order to summarize the clinical utility of genetic testing for Leber congenital amaurosis (LCA). LCA is mostly inherited in an autosomal recessive manner, rarely in an autosomal dominant manner, with an overall prevalence of 2-3/100,000 live births, and is caused by mutations in the AIPL1, CEP290, CRB1, CRX, GDF6, GUCY2D, IFT140, IMPDH1, IQCB1, KCNJ13, LCA5, LRAT, NMNAT1, RD3, RDH12, RPE65, RPGRIP1, SPATA7 and TULP1 genes. Clinical diagnosis involves ophthalmological examination and electrophysiological testing (electroretinography - ERG). The genetic test is useful for confirmation of diagnosis, differential diagnosis, couple risk assessment and access to clinical trials.

We studied the scientific literature and disease guidelines in order to summarize the clinical utility of the genetic test for Mendelian cataract (MC). MC is caused by variations in the AGK, BFSP1, BFSP2, CHMP4B, CRYAA, CRYAB, CRYBA1, CRYBA2, CRYBA4, CRYBB1, CRYBB2, CRYBB3, CRYGC, CRYGD, CRYGS, EPHA2, EYA1, FYCO1, FOXE3, FTL, GALK1, GCNT2, GJA3, GJA8, HSF4, LEMD2, LIM2, LSS, MAF, MIP, NHS, PITX3, PAX6, SIPA1L3, SLC16A12, TDRD7, UNC45B, VIM, VSX, and WFS1 genes. The overall prevalence of congenital forms is 71 per 100 000, whereas there is insufficient data to determine the prevalence of the juvenile and age-related forms. Clinical diagnosis is based on clinical findings, age of onset, family history, ophthalmological examination and slit-lamp examination. The genetic test is useful for confirming diagnosis, and for differential diagnosis, couple risk assessment and access to clinical trials.

We studied the scientific literature and disease guidelines in order to summarize the clinical utility of genetic testing for Mendelian glaucomas, a large heterogeneous group of inherited disorders, classified according to age of onset as congenital glaucoma, juvenile glaucoma and age-related glaucoma. Variations in the TEK, MYOC, ASB10, NTF4, OPA1, WDR36 and OPTN genes are inherited in an autosomal dominant manner and variations in the CYP1B1 and LTBP2 genes have autosomal recessive inheritance. The prevalence of congenital glaucoma is estimated at 1-9 per 100 000, that of juvenile glaucoma at 1 per 50 000, while there is insufficient data to establish the prevalence of age-related glaucoma. Clinical diagnosis is based on clinical findings, age of onset, family history, ophthalmological examination, intraocular pressure, gonioscopy and fundoscopy. The genetic test is useful for confirming diagnosis, and for differential diagnosis, couple risk assessment and access to clinical trials.

We studied the scientific literature and disease guidelines in order to summarize the clinical utility of genetic testing for Mendelian myopia (MM), a large and heterogeneous group of inherited refraction disorders. Variations in the SLC39A5, SCO2 and COL2A1 genes have an autosomal dominant transmission, whereas those in the LRPAP1, P3H2, LRP2 and SLITRK6 genes have autosomal recessive transmission. The prevalence of MM is currently unknown. Clinical diagnosis is based on clinical findings, family history, ophthalmological examination and other tests depending on complications. The genetic test is useful for confirming diagnosis, and for differential diagnosis, couple risk assessment and access to clinical trials.

We studied the scientific literature and disease guidelines in order to summarize the clinical utility of genetic testing for Norrie disease. The disease is caused by variations in the NDP gene. Its prevalence is currently unknown. Inheritance is X-linked recessive. Clinical diagnosis is based on clinical findings, color vision testing, optical coherence tomography, ophthalmological examination and electroretinography. The genetic test is useful for confirming diagnosis, and for differential diagnosis, couple risk assessment and access to clinical trials.

We studied the scientific literature and disease guidelines in order to summarize the clinical utility of genetic testing for ocular albinism and oculocutaneous albinism. Ocular albinism has X-linked recessive inheritance, with a prevalence that varies from 1/40000 to 1/1000000, and is caused by mutations in the GPR143 and CACNA1F genes. Oculocutaneous albinism has autosomal recessive inheritance, with an overall prevalence of 1/17000, and is caused by mutations in the TYR, OCA2, TYRP1, SLC45A2, SLC24A5 and C10orf11 genes. Clinical diagnosis involves ophthalmological examination, testing of visually evoked potentials (VEP) and electrophysiological testing (ERG). The genetic test is useful for confirming diagnosis, differential diagnosis, for couple risk assessment and access to clinical trials.

We studied the scientific literature and disease guidelines in order to summarize the clinical utility of the genetic test for optic atrophy (OA). OA is mostly inherited in an autosomal dominant manner, rarely in an autosomal recessive manner, with an overall prevalence of 3/100,000 live births. It is caused by mutations in the OPA1, OPA3 and TMEM126A genes. Clinical diagnosis is based on clinical findings, ophthalmological examination, OCT, visual evoked potentials (VEPs) and electroretinography. The genetic test is useful for confirming diagnosis, differential diagnosis, couple risk assessment and access to clinical trials.

We studied the scientific literature and disease guidelines in order to summarize the clinical utility of the genetic test for pattern dystrophies. Pattern dystrophies are mostly inherited in an autosomal dominant manner (autosomal recessive transmission is rare). The overall prevalence is currently unknown. Pattern dystrophies are caused by variations in the BEST1, IMPG1, IMPG2, OTX2, PRPH2 and CTNNA1 genes. Clinical diagnosis is based on clinical findings, ophthalmological examination, optical coherence tomography, electrooculography and electroretinography. The genetic test is useful for confirming diagnosis and for differential diagnosis, couple risk assessment and access to clinical trials.

We reviewed the scientific literature and disease guidelines in order to summarize the clinical utility of genetic testing for Refsum disease. The disease has autosomal recessive inheritance, unknown prevalence, and is caused by variations in PEX7 and PHYH genes. Clinical diagnosis is based on clinical findings, ophthalmological examination, electroretinography, optical coherence tomography and phytanic acid assay. The genetic test is useful for confirming diagnosis, for differential diagnosis, couple risk assessment and access to clinical trials.

We reviewed the scientific literature and disease guidelines in order to summarize the clinical utility of genetic testing for non syndromic retinitis pigmentosa (NSRP). NSRP is determined by variations in the ABCA4, AGBL5, ARL2BP, ARL6, BBS2, BEST1, C2orf71, C8orf37, CA4, CDHR1, CERKL, CLRN1, CNGA1, CNGB1, CRB1, CRX, DHDDS, EYS, FAM161A, FSCN2, GUCA1B, HGSNAT, IDH3B, IFT140, IFT172, IMPDH1, IMPG2, KIZ, KLHL7, LRAT, MAK, MERTK, NEK2, NR2E3, NRL, OFD1, PDE6A, PDE6B, PDE6G, POMGNT1, PRCD, PROM1, PRPF3, PRPF31, PRPF4, PRPF6, PRPF8, PRPH2, RBP3, RDH12, RGR, RHO, RLBP1, ROM1, RP1, RP2, RP9, RPE65, RPGR, SAG, SEMA4A, SLC7A14, SNRNP200, SPATA7, TOPORS, TTC8, TULP1, USH2A, ZNF408 and ZNF513 genes. Its overall prevalence is 1 per 4000. It is mostly inherited in an autosomal recessive manner, fewer genes have autosomal dominant or X-linked recessive transmission. Clinical diagnosis is based on clinical findings, ophthalmological examination, best corrected visual acuity (BCVA), slit lamp biomicroscopy, fundus autofluorescence, electroretinography, color vision testing and optical coherence tomography. The genetic test is useful for confirming diagnosis, and for differential diagnosis, couple risk assessment and access to clinical trials.

We studied the scientific literature and disease guidelines in order to summarize the clinical utility of genetic testing for retinitis punctata albescens/fundus albipunctatus (RPA/FA). RPA and FA are reported to have autosomal dominant or autosomal recessive inheritance and are associated with variations in the PRPH2, RHO, RLBP1 and RDH5 genes. There is insufficient data to establish their prevalence. Clinical diagnosis is based on clinical findings, ophthalmological examination, optical coherence tomography, visual field testing and undetectable or severely reduced electroretinogram amplitudes. The genetic test is useful for confirming diagnosis, and for differential diagnosis, couple risk assessment and access to clinical trials.

We studied the scientific literature and disease guidelines in order to summarize the clinical utility of genetic testing for Senior- Loken syndrome (SLSN). SLSN is inherited in an autosomal recessive manner, has a prevalence of one in a million, and is caused by variations in CEP164, CEP290, INVS, IQCB1, NPHP1, NPHP3, NPHP4, SDCCAG8, TRAF3IP1 and WDR19 genes. Clinical diagnosis is based on kidney (urine analysis, abdominal ultrasound, kidney function) and eye assessment (visual acuity test, fundus examination, refraction defects, color testing and electroretinography). The genetic test is useful for confirming diagnosis, and for differential diagnosis, couple risk assessment and access to clinical trials.

We studied the scientific literature and disease guidelines in order to summarize the clinical utility of the genetic test for Sorsby’s fundus dystrophy (SFD). SFD is caused by variations in the TIMP3 gene. Prevalence is, currently unknown. SFD has autosomal dominant inheritance. Clinical diagnosis is based on clinical findings, color vision testing, optical coherence tomography, ophthalmological examination and electroretinography. The genetic test is useful for confirming diagnosis, and for differential diagnosis, couple risk assessment and access to clinical trials.

We studied the scientific literature and disease guidelines in order to summarize the clinical utility of genetic testing for Stargardt macular dystrophy (STGD). STGD is mostly inherited in an autosomal recessive manner and rarely in an autosomal dominant manner, with an overall prevalence of 1-5 per 10 000 live births. It is caused by variations in the ABCA4, CNGB3, ELOVL4, PRPH2 and PROM1 genes. Clinical diagnosis is based on ophthalmological examination, fluorescein angiography, electroretinography, visual field testing, optical coherence tomography and color testing. The genetic test is useful for confirming diagnosis, and for differential diagnosis, couple risk assessment and access to clinical trials.

We studied the scientific literature and disease guidelines in order to summarize the clinical utility of genetic testing for Usher syndrome (USH). USH is mostly transmitted in an autosomal recessive manner and is caused by variations in the ADGRV1, CDH23, CIB2, CLRN1, HARS, MYO7A, PCDH15, PDZD7, USH1C, USH1G, USH2A, WHRN genes. Prevalence is estimated to be 1:30,000. Clinical diagnosis is based on audiogram, vestibular tests, visual acuity test, fundus examination, color test, optical coherence tomography and electroretinography. The genetic test is useful for confirming diagnosis, and for differential diagnosis, couple risk assessment and access to clinical trials.

We studied the scientific literature and disease guidelines in order to summarize the clinical utility of genetic testing for X-linked juvenile retinoschisis (XJR). The disease has X-linked inheritance, a prevalence that varies from one in 5000 to one in 25000 males, and is caused by mutations in the RS1 gene. Clinical diagnosis is based on clinical findings, ophthalmological examination, electroretinography and optical coherence tomography. The genetic test is useful for confirming diagnosis, and for differential diagnosis, couple risk assessment and access to clinical trials.