Novel missense mutation in the bZIP transcription factor, MAF, associated with congenital cataract, developmental delay, seizures and hearing loss (Ayme-Gripp syndrome)

Published online: 08 May 2017Background: Cataract is a major cause of severe visual impairment in childhood. The purpose of this study was to determine the genetic cause of syndromic congenital cataract in an Australian mother and son. Method: Fifty-one genes associated with congenital cataract were sequenced in the proband using a custom Ampliseq library on the Ion Torrent Personal Genome Machine (PGM). Reads were aligned against the human genome (hg19) and variants were annotated. Variants were prioritised for validation by Sanger sequencing if they were novel, rare or previously reported to be associated with paediatric cataract and were predicted to be protein changing. Variants were assessed for segregation with the phenotype in the affected mother. Result: A novel likely pathogenic variant was identified in the transactivation domain of the MAF gene (c.176C > G, p.(Pro59Arg)) in the proband and his affected mother., but was absent in 326 unrelated controls and absent from public variant databases. Conclusion: The MAF variant is the likely cause of the congenital cataract, Asperger syndrome, seizures, hearing loss and facial characteristics in the proband, providinga diagnosis of Aymé-Gripp syndrome for the family.Shari Javadiyan, Jamie E. Craig, Shiwani Sharma, Karen M. Lower, Theresa Casey, Eric Haan, Emmanuelle Souzeau and Kathryn P. Burdo

A novel de novo Myocilin variant in a patient with sporadic juvenile open angle glaucoma

Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.BACKGROUND: Glaucoma is a leading cause of irreversible blindness. Pathogenic variants in the Myocilin gene (MYOC) cause juvenile open angle glaucoma (JOAG) in 8-36% of cases, and display an autosomal dominant inheritance with high penetrance. Molecular diagnosis is important for early identification as therapies are effective in minimizing vision loss and MYOC variants can be associated to severe glaucoma. MYOC variants are usually inherited, however a fifth of carriers do not report a family history. The occurrence of de novo MYOC variants is currently unknown. CASE PRESENTATION: In this study we investigated a 14 year old male Caucasian patient diagnosed with JOAG, and no family history of glaucoma. A novel probably deleterious MYOC:p.(Pro254Leu) variant was identified in the index case. This variant was not present in the parents or the siblings. CONCLUSION: This is the second report of a de novo MYOC variant in a sporadic case of JOAG and it is currently unknown if this mechanism occurs more frequently. This finding emphasizes the importance of screening individuals with JOAG for MYOC mutations irrespective of a negative family history

Loss of ciliary zonule protein hydroxylation and lens stability as a predicted consequence of biallelic ASPH variation

This author accepted manuscript is made available following 12 month embargo from date of publication (January 2019) in accordance with the publisher’s archiving policy “This is an Accepted Manuscript of an article published by Taylor & Francis in Ophthalmic Genetics on 2 January 2019, available online: http://www.tandfonline.com/10.1080/13816810.2018.1561904”Purpose: Stability of the crystalline lens requires formation of microfibril bundles and their higher-order structures of ciliary zonules. Trauma, malformation, or degeneration of the ciliary zonules can lead to dislocation or displacement of the lens, which in turn can cause transient or permanent loss of visual acuity. The purpose of this study was to identify the predicted substrates of ASPH, a 2-oxoglutarate- and Fe2+-dependent hydroxylase, which may account for the lens instability phenotype of ASPH-associated syndromes. Methods: A single proband of European ancestry with spherophakia and high myopia was subjected to exome sequencing. Proteins containing the ASPH hydroxylation motif were identified within the SwissProt protein database. Results: We identified 105 putative substrates of ASPH-mediated hydroxylation in the human proteome, of which two (FBN1 and LTBP2) are associated with inherited ectopia lentis syndromes, and are essential for microfibril and ciliary zonule development. Conclusion: Our results implicate ASPH-mediated hydroxylation in the formation of FBN1/LTBP2 microfibril bundles and competent ciliary zonules

Ethical Considerations for the Return of Incidental Findings in Ophthalmic Genomic Research

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License. Available from PubMed Central (PMC).http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4757467/Whole genome and whole exome sequencing technologies are being increasingly used in research. However, they have the potential to identify incidental findings (IF), findings not related to the indication of the test, raising questions regarding researchers' responsibilities toward the return of this information to participants. In this study we discuss the ethical considerations related to the return of IF to research participants, emphasizing that the type of the study matters and describing the current practice standards. There are currently no legal obligations for researchers to return IF to participants, but some viewpoints consider that researchers might have an ethical one to return IF of clinical validity and clinical utility and that are actionable. The reality is that most IF are complex to interpret, especially since they were not the indication of the test. The clinical utility often depends on the participants' preferences, which can be challenging to conciliate and relies on participants' understanding. In summary, in the context of a lack of clear guidance, researchers need to have a clear plan for the disclosure or nondisclosure of IF from genomic research, balancing their research goals and resources with the participants' rights and their duty not to harm

Predictive genetic testing experience for myocilin primary open-angle glaucoma using the Australian and New Zealand Registry of Advanced Glaucoma

Author version made available in accordance with publisher copyright policy.Purpose: Predictive genetic testing of relatives of known myocilin (MYOC) gene mutation carriers is an appropriate strategy to identify individuals at risk for glaucoma. It is likely to prevent irreversible blindness in this high-risk group because this treatable condition might otherwise be diagnosed late. The Australian and New Zealand Registry of Advanced Glaucoma has established genetic testing protocols for known glaucoma genes, including MYOC. Methods: Through the Australian and New Zealand Registry of Advanced Glaucoma, we investigated the experience of 40 unaffected individuals who had undergone predictive genetic testing for MYOC mutations through questionnaires. Results: The main motivations for being tested were (i) to make appropriate interventions and (ii) to reduce uncertainty. All our respondents perceived strong benefits, either medical or emotional, in being tested. However, different concerns were raised by the respondents that need to be addressed during counseling. Greater family awareness was reported by the majority of the respondents, and the ability to provide information to children was a strong motivation for being tested. Conclusion: This study provides valuable information on the personal and familial impacts of having predictive genetic testing for glaucoma, which will help health professionals to better address the issues faced by patients and provide them adequate support

Compound heterozygote myocilin mutations in a pedigree with high prevalence of primary open-angle glaucoma

This article is an open access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives License 3.0, which permits use, distribution, and reproduction in any medium, provided the original work is properly cited, the use is non commercial and is otherwise in compliance with the license.Purpose: To describe the phenotype of ocular hypertension and primary open-angle glaucoma in a family with individuals compound heterozygote for Gln368STOP and Thr377Met myocilin (MYOC) mutations. Methods: Family members of the proband underwent comprehensive ocular clinical examination and DNA sequencing for MYOC mutations. Results: A 34-year-old woman with marked ocular hypertension was found to carry Gln368STOP and Thr377Met MYOC mutations. Three other siblings carried both mutations, while one carried Gln368STOP alone. Three of five siblings had received treatment for ocular hypertension or early glaucoma, with the average age of diagnosis 28 years; one required trabeculectomy at age 27. The mother of the proband was found to be a carrier for Gln368STOP alone, which indicates that her offspring with both Gln368STOP and Thr377Met carry variants on opposing alleles. Conclusions: This pedigree is the first report with individuals compound heterozygote for the two most common glaucoma-causing MYOC variants. The combination of mutations manifests a more severe phenotype than either alone. Identification of gene changes associated with glaucoma within the family has enabled unaffected members to stratify their risk of future disease and institute closer monitoring and early treatment.CERA receives Operational Infrastructure Support from the Victorian Government. The Australian and New Zealand Registry of Advanced Glaucoma is funded by the RANZCO Eye Foundation. KPB and JEC are funded by a Career Development Award and Practitioner Fellowship from the National Health and Medical Research Council of Australia, respectively

Risk stratification and clinical utility of polygenic risk scores in ophthalmology

Combining genetic and clinical data into an informative risk prediction profile has been an important ambition of personalized medicine. Single-nucleotide polymorphisms are commonly found throughout the genome and account for the majority of interindividual genetic variation. To date, genome-wide association studies have led to the discovery of thousands of disease-associated loci, including across dozens of ophthalmic diseases and traits. However, compared with the clinical utility of identifying rare Mendelian variants, the translation of these results to clinical practice has so far been limited because such variants are found commonly in the population, and individually account for a very small risk. Recently, combining large numbers of these genetic variants into polygenic risk scores (PRS) has shown clinically meaningful risk prediction across several common diseases. PRS have the potential to translate the discovery of common risk variants into individualized disease risk prediction, prognostication, and may enable targeted treatments. In this context, we review the clinical utility of PRS in three common, genetically complex ophthalmic conditions: primary open angle glaucoma, age-related macular degeneration, and myopia. Translational Relevance: Common genetic variants can be used to effectively stratify the risk of disease development and progression and may be used to guide screening, triaging, monitoring, or treatment thresholds.Ayub Qassim, Emmanuelle Souzeau, Georgie Hollitt, Mark M. Hassall, Owen M. Siggs, and Jamie E. Crai

An Assessment of GUCA1C Variants in Primary Congenital Glaucoma

Note: In lieu of an abstract, this is an excerpt from the first page. In the special issue “Molecular Genetics of Retinal Dystrophies”, Morales–Cámara and colleagues reported the association of a new candidate gene with primary congenital glaucoma (PCG) [...

Primary congenital glaucoma due to paternal uniparental isodisomy of chromosome 2 and CYP1B1 deletion

© 2019 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals, Inc. This is an open access article under the terms of the Creative Commons Attribution‐NonCommercial‐NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non‐commercial and no modifications or adaptations are made.Background: CYP1B1 variants and deletions are the most common cause of primary congenital glaucoma (PCG). Methods: We investigated an individual with PCG from the Australian and New Zealand Registry of Advanced Glaucoma. We performed sequencing of the CYP1B1 gene, followed by Multiplex Ligation-dependent Probe Amplification and SNP array. Results: We identified a homozygous deletion of the CYP1B1 gene by Multiplex Ligation-dependent Probe Amplification and confirmed that the father was heterozygous for a CYP1B1 deletion but the mother had normal gene copy number. SNP array identified paternal uniparental isodisomy of the entire chromosome 2. Conclusions: This study is the first report of a homozygous CYP1B1 whole gene deletion due to paternal uniparental isodisomy of chromosome 2 as a cause of PCG. These results illustrate the importance of genetic testing in providing appropriate genetic counseling regarding the risks of recurrence