@article {512, title = {Confirmation of the Role of DHX38 in the Etiology of Early-Onset Retinitis Pigmentosa.}, journal = {Invest Ophthalmol Vis Sci}, volume = {59}, year = {2018}, month = {2018 09 04}, pages = {4552-4557}, abstract = {

Purpose: Retinitis pigmentosa (RP) is a genetically heterogeneous trait with autosomal-recessive (ar) inheritance underlying 50\% of genetic disease cases. Sixty-one arRP genes have been identified, and recently, DHX38 has been reported as a potential candidate gene for arRP with only a single family reported with a variant of unknown significance. We identified a missense variant in DHX38 that co-segregates with the arRP phenotype in two Pakistani families confirming the involvement of DHX38 in the etiology of early-onset RP.

Methods: Exome sequencing was performed using two DNA samples from affected members of Pakistani families (MA88 and MA157) with early onset arRP. Sanger sequencing of DNA samples from all family members confirmed the segregation of candidate variant within both families.

Results: A novel missense DHX38 variant c.971G>A; p.(Arg324Gln) was identified which segregates with the arRP phenotype and yielded a logarithm of the odds (LOD) score of 5.0 and 4.3 for families MA88 and MA157, respectively. This variant is predicted to be conserved and deleterious by several bioinformatics tools.

Conclusions: We identified a second deleterious DHX38 variant that segregates with arRP in two families, providing additional evidence that DHX38 is involved in RP etiology. DHX38 encodes for pre-mRNA splicing factor PRP16, which is important in catalyzing pre-mRNA splicing.

}, keywords = {Adolescent, Adult, Cataract, Computational Biology, DEAD-box RNA Helicases, Female, Genes, Recessive, Genetic Association Studies, Genetic Linkage, Humans, Male, Mutation, Missense, Nucleotide Mapping, Ophthalmoscopy, Pedigree, Retinitis Pigmentosa, RNA Splicing Factors, Sequence Analysis, DNA, Whole Exome Sequencing, Young Adult}, issn = {1552-5783}, doi = {10.1167/iovs.18-23849}, author = {Latif, Zahid and Chakchouk, Imen and Schrauwen, Isabelle and Lee, Kwanghyuk and Santos-Cortez, Regie Lyn P and Abbe, Izoduwa and Acharya, Anushree and Jarral, Afeefa and Ali, Imran and Ullah, Ehsan and Khan, Muhammad Nasim and Ali, Ghazanfar and Tahir, Tufail Hussain and Bamshad, Michael J and Nickerson, Deborah A and Ahmad, Wasim and Ansar, Muhammad and Leal, Suzanne M} } @article {615, title = {Mutation in the intracellular chloride channel CLCC1 associated with autosomal recessive retinitis pigmentosa.}, journal = {PLoS Genet}, volume = {14}, year = {2018}, month = {2018 08}, pages = {e1007504}, abstract = {

We identified a homozygous missense alteration (c.75C>A, p.D25E) in CLCC1, encoding a presumptive intracellular chloride channel highly expressed in the retina, associated with autosomal recessive retinitis pigmentosa (arRP) in eight consanguineous families of Pakistani descent. The p.D25E alteration decreased CLCC1 channel function accompanied by accumulation of mutant protein in granules within the ER lumen, while siRNA knockdown of CLCC1 mRNA induced apoptosis in cultured ARPE-19 cells. TALEN KO in zebrafish was lethal 11 days post fertilization. The depressed electroretinogram (ERG) cone response and cone spectral sensitivity of 5 dpf KO zebrafish and reduced eye size, retinal thickness, and expression of rod and cone opsins could be rescued by injection of wild type CLCC1 mRNA. Clcc1+/- KO mice showed decreased ERGs and photoreceptor number. Together these results strongly suggest that intracellular chloride transport by CLCC1 is a critical process in maintaining retinal integrity, and CLCC1 is crucial for survival and function of retinal cells.

}, keywords = {Animals, Asian Continental Ancestry Group, Cell Line, Chloride Channels, Cytoplasm, Eye Proteins, HEK293 Cells, Homozygote, Humans, Mice, Mice, Knockout, Mutation, Missense, Pakistan, Retina, Retinal Cone Photoreceptor Cells, Retinal Rod Photoreceptor Cells, Retinitis Pigmentosa, Zebrafish}, issn = {1553-7404}, doi = {10.1371/journal.pgen.1007504}, author = {Li, Lin and Jiao, Xiaodong and D{\textquoteright}Atri, Ilaria and Ono, Fumihito and Nelson, Ralph and Chan, Chi-Chao and Nakaya, Naoki and Ma, Zhiwei and Ma, Yan and Cai, Xiaoying and Zhang, Longhua and Lin, Siying and Hameed, Abdul and Chioza, Barry A and Hardy, Holly and Arno, Gavin and Hull, Sarah and Khan, Muhammad Imran and Fasham, James and Harlalka, Gaurav V and Michaelides, Michel and Moore, Anthony T and Coban Akdemir, Zeynep Hande and Jhangiani, Shalini and Lupski, James R and Cremers, Frans P M and Qamar, Raheel and Salman, Ahmed and Chilton, John and Self, Jay and Ayyagari, Radha and Kabir, Firoz and Naeem, Muhammad Asif and Ali, Muhammad and Akram, Javed and Sieving, Paul A and Riazuddin, Sheikh and Baple, Emma L and Riazuddin, S Amer and Crosby, Andrew H and Hejtmancik, J Fielding} } @article {216, title = {New mutations in the RAB28 gene in 2 Spanish families with cone-rod dystrophy.}, journal = {JAMA Ophthalmol}, volume = {133}, year = {2015}, month = {2015 Feb}, pages = {133-9}, abstract = {

IMPORTANCE: The families evaluated in this study represent the second report of cone-rod dystrophy (CRD) cases caused by mutations in RAB28, a recently discovered gene associated with CRD.

OBJECTIVE: To determine the disease-causing gene in 2 families of Spanish descent presenting with CRD who do not have ABCA4 mutations.

DESIGN, SETTING, AND PARTICIPANTS: Molecular genetics and observational case studies of 2 families, each with 1 affected proband with CRD and 3 or 5 unaffected family members. The affected individual from each family received a complete ophthalmic examination including assessment of refractive errors and best-corrected visual acuity, biomicroscopy, color fundus photography, electroretinography analysis, and visual-evoked potential analysis. After complete sequencing of the ABCA4 gene with negative results, the screening for disease-causing mutations was performed by whole-exome sequencing. Possible disease-associated variants were determined by filtering based on minor allele frequency, predicted pathogenicity, and segregation analysis in all family members.

MAIN OUTCOMES AND MEASURES: The appearance of the macula was evaluated by clinical examination, fundus photography, and fundus autofluorescence imaging, and visual function was assessed by electroretinography. Disease-causing mutations were assessed by sequence analyses.

RESULTS: Ophthalmologic findings included markedly reduced visual acuity, bull{\textquoteright}s eye maculopathy, foveal hyperpigmentation, peripapillary atrophy, dyschromatopsia, extinguished photopic responses, and reduced scotopic responses observed on electroretinography consistent with the CRD phenotype often associated with ABCA4 mutations. Although no ABCA4 mutations were detected in either patient, whole-exome sequencing analysis identified 2 new homozygous mutations in the recently described RAB28 gene, the c.172 + 1G>C splice site variant in IVS2 and the missense c.T651G:p.C217W substitution. Both variants were determined as deleterious by predictive programs and were segregated with the disease in both families. Sequencing of 107 additional patients of Spanish descent with CRD did not reveal other cases with RAB28 mutations.

CONCLUSIONS AND RELEVANCE: Deleterious mutations in RAB28 result in a classic CRD phenotype and are an infrequent cause of CRD in the Spanish population.

}, keywords = {Adolescent, Adult, Child, Diagnosis, Differential, DNA Mutational Analysis, Female, Follow-Up Studies, Genetic Predisposition to Disease, Hispanic Americans, Humans, Male, Microscopy, Acoustic, Mutation, Pedigree, Phenotype, rab GTP-Binding Proteins, Retinitis Pigmentosa, Retrospective Studies, Young Adult}, issn = {2168-6173}, doi = {10.1001/jamaophthalmol.2014.4266}, author = {Riveiro-{\'A}lvarez, Rosa and Xie, Yajing Angela and L{\'o}pez-Mart{\'\i}nez, Miguel-{\'A}ngel and Gambin, Tomasz and P{\'e}rez-Carro, Raquel and {\'A}vila-Fern{\'a}ndez, Almudena and L{\'o}pez-Molina, Mar{\'\i}a-Isabel and Zernant, Jana and Jhangiani, Shalini and Muzny, Donna and Yuan, Bo and Boerwinkle, Eric and Gibbs, Richard and Lupski, James R and Ayuso, Carmen and Allikmets, Rando} } @article {106, title = {Safety and Proof-of-Concept Study of Oral QLT091001 in Retinitis Pigmentosa Due to Inherited Deficiencies of Retinal Pigment Epithelial 65 Protein (RPE65) or Lecithin:Retinol Acyltransferase (LRAT).}, journal = {PLoS One}, volume = {10}, year = {2015}, month = {2015}, pages = {e0143846}, abstract = {

UNLABELLED: Restoring vision in inherited retinal degenerations remains an unmet medical need. In mice exhibiting a genetically engineered block of the visual cycle, vision was recently successfully restored by oral administration of 9-cis-retinyl acetate (QLT091001). Safety and visual outcomes of a once-daily oral dose of 40 mg/m2/day QLT091001 for 7 consecutive days was investigated in an international, multi-center, open-label, proof-of-concept study in 18 patients with RPE65- or LRAT-related retinitis pigmentosa. Eight of 18 patients (44\%) showed a >=20\% increase and 4 of 18 (22\%) showed a >=40\% increase in functional retinal area determined from Goldmann visual fields; 12 (67\%) and 5 (28\%) of 18 patients showed a >=5 and >=10 ETDRS letter score increase of visual acuity, respectively, in one or both eyes at two or more visits within 2 months of treatment. In two patients who underwent fMRI, a significant positive response was measured to stimuli of medium contrast, moving, pattern targets in both left and right hemispheres of the occipital cortex. There were no serious adverse events. Treatment-related adverse events were transient and the most common included headache, photophobia, nausea, vomiting, and minor biochemical abnormalities. Measuring the outer segment length of the photoreceptor layer with high-definition optical coherence tomography was highly predictive of treatment responses with responders having a significantly larger baseline outer segment thickness (11.7 {\textpm} 4.8 μm, mean {\textpm} 95\% CI) than non-responders (3.5 {\textpm} 1.2 μm). This structure-function relationship suggests that treatment with QLT091001 is more likely to be efficacious if there is sufficient photoreceptor integrity.

TRIAL REGISTRATION: ClinicalTrials.gov NCT01014052.

}, keywords = {Acyltransferases, Administration, Oral, Adult, Anticarcinogenic Agents, Cerebral Cortex, Child, cis-trans-Isomerases, Drug Dosage Calculations, Female, Humans, Male, Middle Aged, Polymorphism, Single Nucleotide, Radiography, Retinal Ganglion Cells, Retinal Neurons, Retinitis Pigmentosa, Treatment Outcome, Visual Acuity, Visual Fields, Vitamin A, Young Adult}, issn = {1932-6203}, doi = {10.1371/journal.pone.0143846}, author = {Scholl, Hendrik P N and Moore, Anthony T and Koenekoop, Robert K and Wen, Yuquan and Fishman, Gerald A and van den Born, L Ingeborgh and Bittner, Ava and Bowles, Kristen and Fletcher, Emily C and Collison, Frederick T and Dagnelie, Gislin and Degli Eposti, Simona and Michaelides, Michel and Saperstein, David A and Schuchard, Ronald A and Barnes, Claire and Zein, Wadih and Zobor, Ditta and Birch, David G and Mendola, Janine D and Zrenner, Eberhart} } @article {275, title = {Mutations in PCYT1A, encoding a key regulator of phosphatidylcholine metabolism, cause spondylometaphyseal dysplasia with cone-rod dystrophy.}, journal = {Am J Hum Genet}, volume = {94}, year = {2014}, month = {2014 Jan 02}, pages = {105-12}, keywords = {Alleles, Child, Preschool, Choline-Phosphate Cytidylyltransferase, Female, Humans, Infant, Male, Middle Aged, Mutation, Missense, Osteochondrodysplasias, Pedigree, Phosphatidylcholines, Retinitis Pigmentosa}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2013.11.018}, author = {Hoover-Fong, Julie and Sobreira, Nara and Jurgens, Julie and Modaff, Peggy and Blout, Carrie and Moser, Ann and Kim, Ok-Hwa and Cho, Tae-Joon and Cho, Sung Yoon and Kim, Sang Jin and Jin, Dong-Kyu and Kitoh, Hiroshi and Park, Woong-Yang and Ling, Hua and Hetrick, Kurt N and Doheny, Kimberly F and Valle, David and Pauli, Richard M} } @article {242, title = {New syndrome with retinitis pigmentosa is caused by nonsense mutations in retinol dehydrogenase RDH11.}, journal = {Hum Mol Genet}, volume = {23}, year = {2014}, month = {2014 Nov 01}, pages = {5774-80}, abstract = {

Retinitis pigmentosa (RP), a genetically heterogeneous group of retinopathies that occur in both non-syndromic and syndromic forms, is caused by mutations in \~{}100 genes. Although recent advances in next-generation sequencing have aided in the discovery of novel RP genes, a number of the underlying contributing genes and loci remain to be identified. We investigated three siblings, born to asymptomatic parents of Italian-American descent, who each presented with atypical RP with systemic features, including facial dysmorphologies, psychomotor developmental delays recognized since early childhood, learning disabilities and short stature. RP-associated ophthalmological findings included salt-and-pepper retinopathy, attenuation of the arterioles and generalized rod-cone dysfunction as determined by almost extinguished electroretinogram in 2 of 3 siblings. Atypical for RP features included mottled macula at an early age and peripapillary sparing of the retinal pigment epithelium. Whole-exome sequencing data, queried under a recessive model of inheritance, identified compound heterozygous stop mutations, c.C199T:p.R67* and c.C322T:p.R108*, in the retinol dehydrogenase 11 (RDH11) gene, resulting in a non-functional protein, in all affected children. In summary, deleterious mutations in RDH11, an important enzyme for vision-related and systemic retinoic acid metabolism, cause a new syndrome with RP.

}, keywords = {Adolescent, Child, Codon, Nonsense, Female, Humans, Male, Oxidoreductases, Pedigree, Phenotype, Retinitis Pigmentosa, Syndrome, Vision Tests, Visual Acuity, Young Adult}, issn = {1460-2083}, doi = {10.1093/hmg/ddu291}, author = {Xie, Yajing Angela and Lee, Winston and Cai, Carolyn and Gambin, Tomasz and N{\~o}upuu, Kalev and Sujirakul, Tharikarn and Ayuso, Carmen and Jhangiani, Shalini and Muzny, Donna and Boerwinkle, Eric and Gibbs, Richard and Greenstein, Vivienne C and Lupski, James R and Tsang, Stephen H and Allikmets, Rando} }