The application of artificial intelligence in diabetic retinopathy screening: a Saudi Arabian perspective.

Introduction: Diabetic retinopathy (DR) is the leading cause of preventable blindness in Saudi Arabia. With a prevalence of up to 40% of patients with diabetes, DR constitutes a significant public health burden on the country. Saudi Arabia has not yet established a national screening program for DR. Mounting evidence shows that Artificial intelligence (AI)-based DR screening programs are slowly becoming superior to traditional screening, with the COVID-19 pandemic accelerating research into this topic as well as changing the outlook of the public toward it. The main objective of this study is to evaluate the perception and acceptance of AI in DR screening among eye care professionals in Saudi Arabia. Methods: A cross-sectional study using a self-administered online-based questionnaire was distributed by email through the registry of the Saudi Commission For Health Specialties (SCFHS). 309 ophthalmologists and physicians involved in diabetic eye care in Saudi Arabia participated in the study. Data analysis was done by SPSS, and a value of p < 0.05 was considered significant for statistical purposes. Results: 54% of participants rated their level of AI knowledge as above average and 63% believed that AI and telemedicine are interchangeable. 66% believed that AI would decrease the workforce of physicians. 79% expected clinical efficiency to increase with AI. Around 50% of participants expected AI to be implemented in the next 5 years. Discussion: Most participants reported good knowledge about AI. Physicians with more clinical experience and those who used e-health apps in clinical practice regarded their AI knowledge as higher than their peers. Perceived knowledge was strongly related to acceptance of the benefits of AI-based DR screening. In general, there was a positive attitude toward AI-based DR screening. However, concerns related to the labor market and data confidentiality were evident. There should be further education and awareness about the topic.

Identification of Novel CDH23 Variants Causing Moderate to Profound Progressive Nonsyndromic Hearing Loss.

Mutant alleles of CDH23, a gene that encodes a putative calcium-dependent cell-adhesion glycoprotein with multiple cadherin-like domains, are responsible for both recessive DFNB12 nonsyndromic hearing loss (NSHL) and Usher syndrome 1D (USH1D). The encoded protein cadherin 23 (CDH23) plays a vital role in maintaining normal cochlear and retinal function. The present study's objective was to elucidate the role of DFNB12 allelic variants of CDH23 in Saudi Arabian patients. Four affected offspring of a consanguineous family with autosomal recessive moderate to profound NSHL without any vestibular or retinal dysfunction were investigated for molecular exploration of genes implicated in hearing impairment. Parallel to this study, we illustrate some possible pitfalls that resulted from unexpected allelic heterogeneity during homozygosity mapping due to identifying a shared homozygous region unrelated to the disease locus. Compound heterozygous missense variants (p.(Asp918Asn); p.(Val1670Asp)) in CDH23 were identified in affected patients by exome sequencing. Both the identified missense variants resulted in a substitution of the conserved residues and evaluation by multiple in silico tools predicted their pathogenicity and variable disruption of CDH23 domains. Three-dimensional structure analysis of human CDH23 confirmed that the residue Asp918 is located at a highly conserved DXD peptide motif and is directly involved in "Ca2+" ion contact. In conclusion, our study identifies pathogenic CDH23 variants responsible for isolated moderate to profound NSHL in Saudi patients and further highlights the associated phenotypic variability with a genotypic hierarchy of CDH23 mutations. The current investigation also supports the application of molecular testing in the clinical diagnosis and genetic counseling of hearing loss.

Effect of Pegylated Interferon and Mitomycin C on Ocular Surface Squamous Neoplasia in Xeroderma Pigmentosum: A Case Series.

BACKGROUND Xeroderma pigmentosum (XP) is an autosomal recessive disease caused by mutations in DNA repair genes. Clinical manifestations include extreme sensitivity to ultraviolet (UV) rays, freckle-like pigmentation, ocular abnormalities, and an increased risk of developing neoplasms in sun-exposed areas of the skin, mucous membranes, and eyes. This paper describes the clinical outcome of pegylated interferon alpha 2b (PEG-IFN-alpha-2b) subconjunctival injections and topical mitomycin C (MMC) in the treatment of ocular surface squamous neoplasia (OSSN) in patients with XP. CASE REPORT A series of 3 patients with histopathologically-proven biopsy specimens of XP-associated neoplasia of the eyelids and ocular surface underwent subconjunctival injections of PEG-IFN-alpha-2 band topical cycles of MMC. There was a noticeable decrease in the size and severity of ocular surface squamous neoplasia, with minimal adverse effects of flu-like symptoms with mild fever and generalized malaise. Transient mental depression was reported in 2 of our patients, and only 1 patient developed autoimmune diabetes mellitus, which required insulin therapy after the discontinuation of the PEG-IFN-alpha-2b. CONCLUSIONS The literature on the specifics of ocular care using PEG-IFN-alpha-2b for XP-associated OSSN is sparse. However, according to our clinical experience, the combination of PEG-IFN-alpha-2b subconjunctival injection and the topical cycles of MMC is a promising long-term medical therapy to minimize the development and recurrence of OSSN in XP patients.

Asymmetrical Ocular Manifestations of Nephropathic Cystinosis; A Case Report.

BACKGROUND Infantile nephropathic cystinosis is the most common and severe variant of cystinosis, which is a rare autosomal recessive condition related to a defect in the transportation of the protein cystine resulting in its deposition in various organs. Due to the rarity of this condition, only 1 case with extensive ocular involvement has been found in the English-language literature. Here, we report a second such case to highlight the significance of early diagnosis in avoiding devastating but preventable vision loss. CASE REPORT We describe the extensive asymmetrical ocular involvement in a 22-year-old woman who had nephropathic cystinosis since childhood. Despite frequent follow up and systemic and topical cysteamine therapy, she developed ocular complications, including increased intraocular pressure, uveitis, and retinal changes with complete loss of vision in her left eye. In addition, her general condition requires a renal transplant in the near future. CONCLUSIONS Ophthalmologists should be aware of cystinosis and the sequalae of ocular involvement in this disease, despite its rarity. Identification of the earliest corneal deposits should not be overlooked, especially in the context of other systemic manifestations that are indicative of the nephropathic variant of cystinosis.

Unusual Association of Aniridia with Aicardi-Goutières Syndrome-Related Congenital Glaucoma in a Tertiary Care Center.

BACKGROUND Aicardi-Goutières syndrome (AGS) is a rare autosomal recessive encephalopathy of early onset. AGS visual dysfunction range from nystagmus and optic atrophy to cortical blindness in affected individuals; however, congenital glaucoma has been recently noticed among AGS pediatric patients. According to the literature, aniridia has never been recognized among AGS patients. CASE REPORT We report the case of a 4-year-old boy with AGS who had multiple congenital anomalies in the eyes. He was found to have congenital glaucoma, nystagmus, spherophakia with shallow chambers, and aniridia in both eyes. Family history was positive for glaucoma, with consanguineously married parents. According to the genetics report, both parents are carriers of congenital glaucoma genes. A whole-exome sequencing identified IFIH1 heterozygous missense mutation of the patient, which is associated with AGS Type 7. Also, he was diagnosed as having congenital glaucoma with CYP1B1 mutation, homozygous recessive. This case demonstrates the unusual coexistence of bilateral aniridia, a feature not previously reported in ocular findings of AGS. CONCLUSIONS In summary, this is the first reported case of aniridia with AGS-related congenital glaucoma in the literature. This paper summarizes the usual ocular manifestation of AGS, also it highlights atypical ocular features in both; AGS as well as congenital glaucoma. The aim of this paper is to lay the foundation for a national database on AGS in Saudi Arabia, which will help create a bridge between genetic data and clinical findings of AGS patients.

Utility of whole exome sequencing in the diagnosis of Usher syndrome: Report of novel compound heterozygous MYO7A mutations.

Next generation sequencing (NGS), such as targeted panel sequencing, whole-exome sequencing and whole-genome sequencing has led to an exponential increase of elucidated genetic causes in both rare diseases, and common but heterogeneous disorders. NGS is applied in both research and clinical settings, and the clinical exome sequencing (CES), which provides not only the sequence variation data but also clinical interpretation, aids in reaching a final conclusion with regards to a genetic diagnosis. Usher syndrome is a group of disorders, characterized by bilateral sensorineural hearing loss, with or without vestibular dysfunction and retinitis pigmentosa. The index patient, a 2-year-old child was initially diagnosed with nonsyndromic hearing impairment. Homozygosity mapping followed by CES was utilized as a diagnostic tool to identify the genetic basis of his hearing loss. A paternally inherited novel insertion, c.198_199insA (p.Val67Serfs*73) and a maternally inherited novel deletion, c.1219_1226del (p.Phe407Aspfs*33) in gene MYO7A were found in compound heterozygous state in the index patient. The result expands the mutational spectrum of MYO7A. In addition it helped in early diagnosis of the syndrome, for planning and adjustments for the patient, and as well as for future family planning. This study highlights the clinical effectiveness of CES for Usher syndrome diagnosis in a child presented with congenital hearing loss.

Expanding the clinical, allelic, and locus heterogeneity of retinal dystrophies.

PURPOSE: Retinal dystrophies (RD) are heterogeneous hereditary disorders of the retina that are usually progressive in nature. The aim of this study was to clinically and molecularly characterize a large cohort of RD patients. METHODS: We have developed a next-generation sequencing assay that allows known RD genes to be sequenced simultaneously. We also performed mapping studies and exome sequencing on familial and on syndromic RD patients who tested negative on the panel. RESULTS: Our panel identified the likely causal mutation in >60% of the 292 RD families tested. Mapping studies on all 162 familial RD patients who tested negative on the panel identified two novel disease loci on Chr2:25,550,180-28,794,007 and Chr16:59,225,000-72,511,000. Whole-exome sequencing revealed the likely candidate as AGBL5 and CDH16, respectively. We also performed exome sequencing on negative syndromic RD cases and identified a novel homozygous truncating mutation in GNS in a family with the novel combination of mucopolysaccharidosis and RD. Moreover, we identified a homozygous truncating mutation in DNAJC17 in a family with an apparently novel syndrome of retinitis pigmentosa and hypogammaglobulinemia. CONCLUSION: Our study expands the clinical and allelic spectrum of known RD genes, and reveals AGBL5, CDH16, and DNAJC17 as novel disease candidates.Genet Med 18 6, 554-562.

An siRNA-based functional genomics screen for the identification of regulators of ciliogenesis and ciliopathy genes.

Defects in primary cilium biogenesis underlie the ciliopathies, a growing group of genetic disorders. We describe a whole-genome siRNA-based reverse genetics screen for defects in biogenesis and/or maintenance of the primary cilium, obtaining a global resource. We identify 112 candidate ciliogenesis and ciliopathy genes, including 44 components of the ubiquitin-proteasome system, 12 G-protein-coupled receptors, and 3 pre-mRNA processing factors (PRPF6, PRPF8 and PRPF31) mutated in autosomal dominant retinitis pigmentosa. The PRPFs localize to the connecting cilium, and PRPF8- and PRPF31-mutated cells have ciliary defects. Combining the screen with exome sequencing data identified recessive mutations in PIBF1, also known as CEP90, and C21orf2, also known as LRRC76, as causes of the ciliopathies Joubert and Jeune syndromes. Biochemical approaches place C21orf2 within key ciliopathy-associated protein modules, offering an explanation for the skeletal and retinal involvement observed in individuals with C21orf2 variants. Our global, unbiased approaches provide insights into ciliogenesis complexity and identify roles for unanticipated pathways in human genetic disease.

Signet ring cell adenocarcinoma and bilateral leptomeningeal involvement of optic nerve sheaths.

Signet ring cell adenocarcinoma has a propensity for leptomeningeal carcinomatosis, and although bilateral optic nerve involvement is rare, this may occur with or without obvious signs of diffuse leptomeningeal involvement. We describe a 41-year-old woman who presented with a brief history of simultaneous bilateral visual deterioration and a distended abdomen. Examination revealed bilateral no light perception vision and bilateral optic disc edema. Radiologic work-up showed large multiple pelvic masses involving the ovaries, multifocal boney deposits, and widespread central nervous system carcinomatosis, involving the optic nerves and the first, fifth, and eighth cranial nerves. Biopsy of an ovarian mass demonstrated islands of signet ring cells. Signet cell adenocarcinomatous infiltration of the leptomeningeal space should be considered in cases of bilateral simultaneous vision loss with signs suggestive of leptomeningeal infiltration of the optic nerve sheath.

LOXL3, encoding lysyl oxidase-like 3, is mutated in a family with autosomal recessive Stickler syndrome.

Stickler syndrome (SS) is a collagenopathy characterized by arthropathy and vitreoretinopathy with high myopia and cleft palate as common features. In a family with an autosomal recessive SS that does not map to genes known to cause autosomal recessive forms of SS, we combined autozygome and exome analysis to identify a novel missense variant in LOXL3 as the likely candidate cause. LOXL3 cross-links collagen II and its morphants phenocopy the craniofacial defects characteristic of collagen XI deficiency. We propose LOXL3 as a novel candidate gene for autosomal recessive SS.

ILDR1: Novel mutation and a rare cause of congenital deafness in the Saudi Arabian population.

Hearing impairment is the common human sensorineural disorder and is a genetically heterogeneous phenotype for which more than 100 genomic loci have been mapped so far. ILDR1 located on chromosome 3q13.33, encodes a putative transmembrane receptor containing an immunoglobulin-like domain. We used a combination of autozygosity mapping and candidate gene sequencing to identify a novel mutation in ILDR1, as a causative gene for autosomal-recessive non-syndromic hearing loss (arNSHL) in a consanguineous Saudi family with three affected children. Autozygosity mapping identified a shared region between the affected individuals encompassing ILDR1 on chromosome 3q13.12-3q22.1. Sequencing revealed homozygous 9 base pair duplication, resulting in an in-frame duplication of three amino acids p.(Asn109_Pro111dup). The mutation was segregating with the disease phenotype and is predicted to be pathogenic by SIFT and PROVEAN. The identified mutation is located in the immunoglobulin-type domain of the ILDR1 protein. In silico analysis using I-TASSER server and PyMOL offers the first predictions on the structural and functional consequences of this mutation. To our knowledge, this is the first ILDR1 mutation identified in a Saudi family. Identification of ILDR1 mutation in only one of 100 Saudi familial and sporadic individuals with hearing loss suggests that this mutation is unique to this family and that ILDR1 should be considered as a rare cause of congenital deafness among Saudi Arabian population. Our data also confirms the evidence for ILDR1 allelic heterogeneity and expands the number of familial arNSHL-associated ILDR1 gene mutations.

IFT27, encoding a small GTPase component of IFT particles, is mutated in a consanguineous family with Bardet-Biedl syndrome.

Bardet-Biedl syndrome (BBS) is an autosomal recessive ciliopathy with multisystem involvement. So far, 18 BBS genes have been identified and the majority of them are essential for the function of BBSome, a protein complex involved in transporting membrane proteins into and from cilia. Yet defects in the identified genes cannot account for all the BBS cases. The genetic heterogeneity of this disease poses significant challenge to the identification of additional BBS genes. In this study, we coupled human genetics with functional validation in zebrafish and identified IFT27 as a novel BBS gene (BBS19). This is the first time an intraflagellar transport (IFT) gene is implicated in the pathogenesis of BBS, highlighting the genetic complexity of this disease.

COL4A4-related nephropathy caused by a novel mutation in a large consanguineous Saudi family.

INTRODUCTION: Collagen type IV related nephropathies are due to the defects in collagen IV genes COL4A3, COL4A4, or COL4A5 and comprise a spectrum of phenotypes ranging from Alport Syndrome (AS) to its mild variants, termed as familial haematuria or thin basement membrane nephropathy. Classical AS is a progressive renal disease presenting with a triad of progressive hematuric nephritis and typical extra-renal complications, such as sensorineural hearing loss (SNHL) and variable ocular anomalies. The mode of inheritance in AS is X-linked in 85%, autosomal recessive in 15%, and autosomal dominant in rare cases. OBJECTIVES: This study aims to identify underlying mutation in multiple individuals from a large consanguineous Saudi family with inherited nephropathy, including our index patient who manifested all the features of classical AS. PATIENTS AND METHODS: Patients were diagnosed by nephrologists and clinical geneticists. All the individuals underwent clinical, audiological and ophthalmological evaluation. Blood samples were collected after written informed consent. DNA extraction, homozygosity mapping and PCR amplification followed standard methodologies. RESULTS: The disease locus was mapped to 2q36.3, where both COL4A3 and COL4A4 reside. Sanger sequencing of COL4A3 and COL4A4 revealed an underlying novel homozygous disease-causing COL4A4 mutation (c.2420delG; p.G807fsX60) in the affected proband. Considerable phenotypic variability segregating with this COL4A4 mutation in our study family is documented. The homozygous mutants were manifesting end-stage renal disease (ESRD) in their adolescence, while the heterozygous carrier members were presenting with considerable phenotypic heterogeneity ranging from intermittent hematuria to late onset ESRD. In addition, there is a relatively severe involvement of the ear (SNHL) and eye in the homozygotes than the heterozygotes. Fertility problems were also noted in both of the homozygous females. CONCLUSION: Identification of the causative mutation is an efficient strategy for conclusive molecular diagnosis in the patients and to establish genotype/phenotype correlation. It is important to study and evaluate asymptomatic carriers, to predict prognosis of the disease and to obviate the need for another renal biopsy in at-risk related family members. While an accurate genetic diagnosis of AS provides valuable information for genetic counseling in the extended family members, it can also facilitate future prenatal diagnosis and planning for pre-implantation genetic diagnosis.

Mutations in c12orf57 cause a syndromic form of colobomatous microphthalmia.

Microphthalmia is an important developmental eye disorder. Although mutations in several genes have been linked to this condition, they only account for a minority of cases. We performed autozygome analysis and exome sequencing on a multiplex consanguineous family in which colobomatous microphthalmia is associated with profound global developmental delay, intractable seizures, and corpus callosum abnormalities, and we identified a homozygous truncating mutation in C12orf57 [c.1A>G; p.Met1?]. In a simplex case with a similar phenotype, we identified compound heterozygosity for the same mutation and another missense mutation [c.152T>A; p.Leu51Gln]. Little is known about C12orf57 but we show that it is expressed in several mouse tissues, including the eye and brain. Our data strongly implicate mutations in C12orf57 in the pathogenesis of a clinically distinct autosomal-recessive syndromic form of colobomatous microphthalmia.

Autozygome-guided exome sequencing in retinal dystrophy patients reveals pathogenetic mutations and novel candidate disease genes.

Retinal dystrophy (RD) is a heterogeneous group of hereditary diseases caused by loss of photoreceptor function and contributes significantly to the etiology of blindness globally but especially in the industrialized world. The extreme locus and allelic heterogeneity of these disorders poses a major diagnostic challenge and often impedes the ability to provide a molecular diagnosis that can inform counseling and gene-specific treatment strategies. In a large cohort of nearly 150 RD families, we used genomic approaches in the form of autozygome-guided mutation analysis and exome sequencing to identify the likely causative genetic lesion in the majority of cases. Additionally, our study revealed six novel candidate disease genes (C21orf2, EMC1, KIAA1549, GPR125, ACBD5, and DTHD1), two of which (ACBD5 and DTHD1) were observed in the context of syndromic forms of RD that are described for the first time.

Homozygous null mutation in ODZ3 causes microphthalmia in humans.

PURPOSE: Microphthalmia is a condition in which eyes are small in size, often associated with coloboma, as a result of aberrant eye development. Isolated microphthalmia is a model disease for studying early development of the human eye, and mutations in several key genes related to eye development have been linked to this phenotype. METHODS: In our search for novel genes that cause autosomal recessive microphthalmia when mutated, we enrolled a family that consists of third-cousin parents and two children with isolated colobomatous microphthalmia. RESULTS: Exome and autozygome analysis identified a null mutation in ODZ3, one of four vertebrate orthologs of odz in Drosophila. CONCLUSION: Our data highlight a role for ODZ3 in the early development of the human eye.

RP1 and retinitis pigmentosa: report of novel mutations and insight into mutational mechanism.

BACKGROUND/AIM: Retinitis pigmentosa (RP) is the commonest form of retinal dystrophy and is usually inherited as a monogenic trait but with remarkable genetic heterogeneity. RP1 is one of the earliest identified disease genes in RP with mutations in this gene known to act both recessively and dominantly although the mutational mechanism remains unclear. This study is part of our ongoing effort to characterise RP in Saudi Arabia at the molecular level. METHODS: Homozygosity mapping and candidate gene analysis. RESULTS: The authors have identified four novel mutations, all recessive, in a number of families with a typical RP phenotype. CONCLUSION: The distribution of these novel and previously reported RP1 mutations makes it challenging to describe a unifying mutational mechanism for dominant versus recessive RP1-related RP.

In search of triallelism in Bardet-Biedl syndrome.

Bardet-Biedl syndrome (BBS) is a model disease for ciliopathy in humans. The remarkable genetic heterogeneity that characterizes this disease is consistent with accumulating data on the interaction between the proteins encoded by the 14 BBS genes identified to date. Previous reports suggested that such interaction may also extend to instances of oligogenic inheritance in the form of triallelism which defies the long held view of BBS as an autosomal recessive disease. In order to investigate the magnitude of triallelism in BBS, we conducted a comprehensive analysis of all 14 BBS genes as well as the CCDC28B-modifier gene in a cohort of 29 BBS families, most of which are multiplex. Two in trans mutations in a BBS gene were identified in each of these families for a total of 20 mutations including 12 that are novel. In no instance did we observe two mutations in unaffected members of a given family, or observe the presence of a third allele that convincingly acted as a modifier of penetrance and supported the triallelic model of BBS. In addition to presenting a comprehensive genotype/phenotype overview of a large set of BBS mutations, including the occurrence of nonsyndromic retinitis pigmentosa in a family with a novel BBS9 mutation, our study argues in favor of straightforward autosomal recessive BBS in most cases.

Progression of age-related macular degeneration after cataract surgery.

OBJECTIVE: To document age-related macular degeneration (AMD) progression after cataract surgery. METHODS: Surgeons prospectively enrolled patients with nonneovascular AMD who were awaiting cataract surgery. Fluorescein angiography was performed preoperatively and at the postoperative week 1, month 3, and month 12 visits. Incidence of neovascular AMD development within 12 months after operation was the primary outcome measure. RESULTS: A total of 108 subjects were enrolled. Of 86 eyes with preoperatively photographically confirmed nonneovascular AMD, 71 had gradable images by month 12. Neovascular AMD was observed in 9 of 71 eyes (12.7%; 95% confidence interval, 6.0%-22.7%). The progression rate between week 1 and month 12 decreased to 3 of 65 eyes (4.6%; 95% confidence interval, 1.0%-12.9%) after excluding 5 neovascular events identified on the postoperative week 1 visit and 1 case with missing photographs at this visit. CONCLUSION: The low incidence rate of neovascular AMD development between 1 week and 1 year after cataract surgery did not support the hypothesis that cataract surgery increases the risk of AMD progression. Several eyes appeared to have disease progression on postsurgery week 1 fluorescein angiograms, suggesting that many cases of presumed progression to neovascular AMD following cataract surgery may have been present prior to cataract surgery, but not recognized owing to lens opacity.