To facilitate ophthalmologists' understanding on the cost of genetic testing in ocular disease, the complexities of insurance coverage and its impact on the availability of testing.
Many insurance ...carriers address coverage for genetic testing in written clinical policies. They provide criteria for medically necessary testing. These policies mostly cover testing for individuals who are symptomatic and in whom testing will have a direct impact on medical treatment. In cases in which no treatments are currently available, other than research trials, patients may have difficulty in getting insurance coverage for genetic testing.
Genetic testing for inherited eye diseases can be costly but has many benefits to patient care, including confirmation of a diagnosis, insight into prognostic information, and identification of associated health risks, inheritance patterns, and possible current and future treatments. As gene therapy advances progress, the availability for treatment in ocular diseases, coverage for genetic testing by third-party payers could increase on the basis of current clinical policies.
Retinitis pigmentosa (RP) is a major cause of blindness that affects 1.5 million people worldwide. Mutations in cyclic nucleotide-gated channel β 1 (CNGB1) cause approximately 4% of autosomal ...recessive RP. Gene augmentation therapy shows promise for treating inherited retinal degenerations; however, relevant animal models and biomarkers of progression in patients with RP are needed to assess therapeutic outcomes. Here, we evaluated RP patients with CNGB1 mutations for potential biomarkers of progression and compared human phenotypes with those of mouse and dog models of the disease. Additionally, we used gene augmentation therapy in a CNGβ1-deficient dog model to evaluate potential translation to patients. CNGB1-deficient RP patients and mouse and dog models had a similar phenotype characterized by early loss of rod function and slow rod photoreceptor loss with a secondary decline in cone function. Advanced imaging showed promise for evaluating RP progression in human patients, and gene augmentation using adeno-associated virus vectors robustly sustained the rescue of rod function and preserved retinal structure in the dog model. Together, our results reveal an early loss of rod function in CNGB1-deficient patients and a wide window for therapeutic intervention. Moreover, the identification of potential biomarkers of outcome measures, availability of relevant animal models, and robust functional rescue from gene augmentation therapy support future work to move CNGB1-RP therapies toward clinical trials.
Genetics of the anterior segment dysgenesis Paredes, Diego I; Capasso, Jenina E; Wyman, Celeste S ...
Taiwan journal of ophthalmology,
10/2023, Letnik:
13, Številka:
4
Journal Article
Recenzirano
Odprti dostop
The anterior segment dysgeneses are a broad group of heterogeneous disorders characterized by developmental abnormalities of the anterior segment of the eye, including primary congenital aphakia, ...Peters sequence, aniridia, and Axenfeld-Rieger spectrum. These conditions can have overlapping phenotypes and both genotypic and phenotypic heterogeneity. This article provides a strategy for both phenotyping and then genotyping using a targeted stepwise approach.
Heimler syndrome (HS) consists of recessively inherited sensorineural hearing loss, amelogenesis imperfecta (AI) and nail abnormalities, with or without visual defects. Recently HS was shown to ...result from hypomorphic mutations in PEX1 or PEX6, both previously implicated in Zellweger Syndrome Spectrum Disorders (ZSSD). ZSSD are a group of conditions consisting of craniofacial and neurological abnormalities, sensory defects and multi-organ dysfunction. The finding of HS-causing mutations in PEX1 and PEX6 shows that HS represents the mild end of the ZSSD spectrum, though these conditions were previously thought to be distinct nosological entities. Here, we present six further HS families, five with PEX6 variants and one with PEX1 variants, and show the patterns of Pex1, Pex14 and Pex6 immunoreactivity in the mouse retina. While Ratbi et al. found more HS-causing mutations in PEX1 than in PEX6, as is the case for ZSSD, in this cohort PEX6 variants predominate, suggesting both genes play a significant role in HS. The PEX6 variant c.1802G>A, p.(R601Q), reported previously in compound heterozygous state in one HS and three ZSSD cases, was found in compound heterozygous state in three HS families. Haplotype analysis suggests a common founder variant. All families segregated at least one missense variant, consistent with the hypothesis that HS results from genotypes including milder hypomorphic alleles. The clinical overlap of HS with the more common Usher syndrome and lack of peroxisomal abnormalities on plasma screening suggest that HS may be under-diagnosed. Recognition of AI is key to the accurate diagnosis of HS.
Retinitis pigmentosa (RP) is the leading cause of heritable retinal visual impairment. Clinically, it is characterized by a variable onset of progressive night blindness and visual field ...constriction. RP is characterized by wide genetic heterogeneity with a broad range of potential genes involved in the genesis of this disease. Very few cases have been reported of RP due to pathogenic variants in
.
We report two patients with RP and bilallelic pathogenic variants in
.
Genetic sequencing showed one homozygous
missense variant in one patient and a homozygous nonsense variant in the other. These patients presented with progressive peripheral vision loss and nyctalopia. Their RP phenotypes were similar to previous reports in literature.
These two cases provide further evidence regarding the relationship of pathogenic variants in
as a cause of autosomal recessive RP.
The purpose of this article is to determine the cause of Leber congenital amaurosis (LCA) in Chuuk state, Federated States of Micronesia (FSM). In this prospective observational case series, five ...patients with early-onset vision loss were examined in Chuuk state, FSM, during an ocular genetics visit to study the elevated incidence of microphthalmia. Because of their low vision these patients were incorrectly assumed to have microphthalmia. A complete ophthalmological exam established a clinical diagnosis of LCA. Candidate gene exons were sequenced with a targeted retinal dystrophy panel. Five subjects in three related families were diagnosed with LCA. All five were from Tonoas Island, within the Chuuk Lagoon, with ages ranging from 6 months to 16 years. DNA sequencing of affected individuals revealed a homozygous CRB1 NM_201253.3:c.3134del pathogenic variant, which was heterozygous in their parents. CRB1 genotypes were confirmed by a PCR restriction assay. We report identification of a founder pathogenic variant in CRB1 responsible for autosomal recessive LCA in this isolated community. This discovery will lead to appropriate recurrence risk counseling.
Many serious, potentially blinding eye disorders have a genetic basis. Currently, there are relatively few ocular geneticists in the world, yet inherited eye disease is one of the leading causes of ...blindness worldwide. Significant strides have been made in gene identification and acquisition of knowledge on the underlying mechanisms of hereditary eye disease. The field of ocular genetics is becoming an increasingly relevant part of ophthalmologists' purview. This has resulted in a dire need for a comprehensive textbook ophthalmologists and other professionals who work with patients with genetic disorders can utilize to gain a better understanding of inherited eye disorders. The Wills Eye Handbook of Ocular Genetics, by Alex Levin, Mario Zanolli, and Jenina Capasso of Wills Eye Hospital, is a practical, reader-friendly guide on the diagnosis and management of ophthalmic genetic conditions. Every chapter begins with a disease overview, followed by relevant modern genetic concepts, pathways to attaining the correct diagnosis, and pitfalls and pearls gleaned from years of hands-on expertise. At the end of each chapter, questions and answers enable readers to test their knowledge in real-life scenarios they might face in everyday practice. The ultimate goal of this clinically robust handbook is to facilitate optimal patient management and outcomes. Key Features * Fundamentals, including basic genetics, inheritance patterns, genetic testing, and ethical issues * Patient-centered genetic counseling issues such as reproduction, dealing with emotional reactions, prognosis, and future options * Anterior segment disorders - from corneal dystrophies and aniridia - to childhood cataract and microphthalmia * A broad spectrum of vitreoretinopathies and retinal diseases including incontinentia pigmenti, retinitis pigmentosa, Bardet-Biedl syndrome, choroideremia, Stargardt disease, achromatopsia, and juvenile X-linked retinoschisis This textbook is essential reading for practitioners at all levels and in all subspecialties including ophthalmology and genetics. They will find it an excellent resource for navigating the complexities of genetic eye disease.
Ocular manifestations of PACS1 mutation Pefkianaki, Maria; Schneider, Adele; Capasso, Jenina E. ...
Journal of AAPOS,
August 2018, 2018-08-00, 20180801, Letnik:
22, Številka:
4
Journal Article
Recenzirano
Heterozygous mutation in the PACS1 (phosphofurin acidic cluster sorting proteins 1) gene is a known cause of developmental delay, multiple congenital anomalies, dysmorphism, and ocular abnormalities. ...We present the case of an affected 10-year-old girl, conceived by assisted reproductive technology, who has ocular coloboma and findings characteristic of PACS1 mutation.
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