Pseudo-Gaze Deviation Resulting From Positive Angle Kappa and Esotropia.

ABSTRACT: A 6-year-old boy was referred for constant right gaze deviation. Rather than a gaze deviation, he constantly seemed to look on the left side of any displayed target. Examination revealed the association of a highly positive angle Kappa and an esotropia of equal values. He also exhibited signs of ocular albinism with no associated infantile nystagmus syndrome. The X-linked ocular albinism was confirmed genetically, explaining the presence of a positive angle Kappa. A highly positive angle Kappa can be associated with a convergent strabismus; in case both values offset each other, this can result in a constant "sidelooking," which should not be confused with a gaze deviation.

Ophthalmological abnormalities in Down syndrome among Brazilian patients.

Down syndrome is the most common chromosomal disorder, affecting 1/700 live births. Among the clinical findings, one constant concern is the high prevalence of visual disorders that, if left untreated, can negatively affect child development. The aim of this study was to determine the prevalence of ophthalmological findings among patients who attended an outpatient clinic for patients with Down syndrome in southern Brazil between 2005 and 2016. A cross-sectional study including 1,207 patients medical records were done, which 492 (40.8%) had some ophthalmological disorder. These data were subjected to descriptive analysis using Statistica software. Among the 492 patients with any ophthalmological disease, the need for glasses was found in 434 (36%) patients, keratoconus in 254 (42.1%), congenital cataract in 27 (15.1%), nasolacrimal duct obstruction in 25 (2.0%), strabismus in 22 (1.9%), nystagmus in four (0.3%), and juvenile cataract in two (0.2%). Two young adults with keratoconus underwent corneal transplantation. Although the prevalence of an ophthalmological disease among the present sample (40.8%) was lower than described in the current literature, it still reinforced the importance of routine and early evaluations in infants. These should begin at 6 months of age and be repeated half-year until 2 years old, annually until 7 years old, biennial in adolescents, and triennial in adults and elderly. Our findings of a high frequency of keratoconus support a detailed corneal study in such patients for early detection and treatment.

A novel MFRP gene variant in a family with posterior microphthalmos, retinitis pigmentosa, foveoschisis, and foveal hypoplasia.

BACKGROUND: To characterize the phenotype and genotype of a syndrome associating posterior microphthalmos (PM), retinitis pigmentosa (RP), foveoschisis, and foveal hypoplasia (FH) in a consanguineous Portuguese family. MATERIALS AND METHODS: Three siblings were studied and underwent comprehensive eye examinations for best-corrected visual acuity, axial length, refractive error, B-mode ultrasound, electroretinography, retinography, fluorescein angiography (FA), kinetic visual field (VF), and optical coherence tomography (OCT). Molecular analysis was performed by Sanger sequencing of the entire coding region of the MFRP gene. RESULTS: All members presented nyctalopia, decreased visual acuity, and constriction of the VF, as well as bilateral shortening of the posterior ocular segment and normal anterior segment dimensions. The fundoscopy and ERG results were compatible with RP. Macular OCT analysis revealed schisis of the outer retinal layer, FH, as well as retinal and choroidal folds. We identified a homozygous mutation in intron 9 of the membrane frizzled-related protein (MFRP) gene (c.1124 + 1 G > A). CONCLUSIONS: Our study shows a family with PM and RP due to a mutation in the MFRP gene. The relationship has previously been proven, but this specific mutation has never been described. These gene mutations show wide phenotypic variability, being evident in the presence of foveoschisis, retinal and choroidal folds, and FH, other than PM and RP.

Left ventricular noncompaction in a Para athlete.

The left ventricular noncompaction is a congenital cardiomyopathy characterized by the presence of abnormal trabeculations in the left ventricle. The present study describes the case of a 14-year-old female Para athlete, who plays goalball. She was asymptomatic, with history of congenital nystagmus and mild visual impairment, who presented nonspecific electrocardiographic abnormalities during pre-competition screening. Cardiac magnetic resonance imaging showed left ventricular non-compaction (non-compacted to compacted layer ratio equal to 2.5) and mild biventricular systolic dysfunction. Initially, the patient was excluded from sports participation and clinical follow-up was performed every three months. Patient remained asymptomatic during the one-year follow-up, with no history of unexplained syncope, marked impairment of systolic function or significant ventricular arrhythmias at the exercise stress test. Finally, she was released for competitive goalball participation and clinical follow-up was continued every 6 months. There is no consensus regarding the eligibility criteria for sports participation in cases of left ventricular non-compaction. Thus, it is prudent to individualize the decision regarding practice of sports, as well as to consider participation in competitive sports for asymptomatic individuals and with no disease repercussions.

Fovea Plana in a 9-Year-Old Boy Presenting with Decreased Vision in the Left Eye.

BACKGROUND Foveal hypoplasia (FH) is a congenital disorder, generally associated with other conditions. CASE REPORT A 9-year-old boy presented with moderately decreased vision in the left eye. Fundus examination showed an absence of macular reflection and no foveal pit was seen on optical coherence tomography. Fluorescein angiography demonstrated the absence of a foveal avascular zone. CONCLUSIONS This is a rare case of a unilateral fovea plana associated with a visual impairment.

Left ventricular noncompaction in a Para athlete / Miocárdio não compactado em paratleta

ABSTRACT The left ventricular noncompaction is a congenital cardiomyopathy characterized by the presence of abnormal trabeculations in the left ventricle. The present study describes the case of a 14-year-old female Para athlete, who plays goalball. She was asymptomatic, with history of congenital nystagmus and mild visual impairment, who presented nonspecific electrocardiographic abnormalities during pre-competition screening. Cardiac magnetic resonance imaging showed left ventricular non-compaction (non-compacted to compacted layer ratio equal to 2.5) and mild biventricular systolic dysfunction. Initially, the patient was excluded from sports participation and clinical follow-up was performed every three months. Patient remained asymptomatic during the one-year follow-up, with no history of unexplained syncope, marked impairment of systolic function or significant ventricular arrhythmias at the exercise stress test. Finally, she was released for competitive goalball participation and clinical follow-up was continued every 6 months. There is no consensus regarding the eligibility criteria for sports participation in cases of left ventricular non-compaction. Thus, it is prudent to individualize the decision regarding practice of sports, as well as to consider participation in competitive sports for asymptomatic individuals and with no disease repercussions.

RESUMO O miocárdio não compactado é uma cardiomiopatia congênita caracterizada pela presença de trabeculações anormais no ventrículo esquerdo. O presente estudo descreve o caso de uma paratleta de goalball, 14 anos, sexo feminino, assintomática, com história pessoal de nistagmo congênito e leve deficiência visual, que apresentou alterações eletrocardiográficas inespecíficas durante avaliação pré-participação. A ressonância magnética cardíaca evidenciou presença de não compactação miocárdica (relação entre camada não compactada/camada compactada igual a 2,5) e disfunção sistólica biventricular leve. Inicialmente, a paciente foi afastada da prática de esportes, e o seguimento clínico foi realizado a cada 3 meses. A paciente permaneceu assintomática durante o período de 1 ano de seguimento, sem história de síncope inexplicada, comprometimento significativo da função sistólica ou taquiarritmias ventriculares importantes ao teste de esforço. Por fim, ela foi liberada para prática competitiva de goalball, e o seguimento clínico foi mantido a cada 6 meses. Não há consenso quanto aos critérios de elegibilidade para a prática esportiva nos casos de miocárdio não-compactado. Assim, é prudente individualizar a decisão quanto a prática esportiva, bem como considerar a participação em esportes competitivos para indivíduos assintomáticos e sem repercussões da doença.

Molecular analysis of Cypriot families with aniridia reveals a novel PAX6 mutation.

The present study investigated the clinical and mutational spectrum of aniridia in a cohort of 17 affected individuals from six families from Cyprus. Each proband was initially evaluated for copy number variants at the PAX6 locus and subsequently underwent PAX6 mutation screening. Sequence analysis of FOXC1 and PITX2 was performed in patients who did not carry a PAX6 mutation. The most common clinical features in the group of aniridia patients associated with aniridia were nystagmus, cataracts and glaucoma. PAX6 pathogenic mutations were identified in five out of six families (a diagnostic yield of 84%). Previously reported pathogenic mutations in PAX6 were identified in four families, which comprise p.R203*, p.R240* and p.R317*. In addition, a novel pathogenic variant (p.E220Gfs*23) was identified in a single family. No pathogenic mutations were detected in PAX6, FOXC1 or PITX2 in the only patient with a sporadic form of aniridia­like phenotype, confirming the genetic heterogeneity associated with this disease. To the best of our knowledge this is the first report on the mutational spectrum of PAX6 in aniridia patients of Cypriot ancestry. Mutational screening of PAX6 serves a crucial role in distinguishing isolated from syndromic forms of aniridia, and it may therefore eliminate the need for renal ultrasound scan surveillance, delineate the phenotype and improve genetic counseling.

[Clinical characteristics and surgical treatment of idiopathic congenital nystagmus in 224 patients].

OBJECTIVE: To study clinical characteristics and surgical treatment of idiopathic congenital nystagmus (ICN). METHODS: A retrospective study was conducted in 224 patients with ICN in Tianjin eye hospital from July 2007 to February 2013. RESULTS: There were 224 patients, 158 (70.54%) males and 66 (29.5%) females, mean age was (11.6±8.4) years and (11.4±6.4) years separately. Horizontal nystgamus happened in 215 cases, 3 cases were vertical type and 6 cases were mixed. 214 cases were with no history of operation and 10 patients had ever underwent surgeries before. Furthermore, 151 patients combined with strabismus and refractive error, anterior segment or retinal disorders, which accounting for 67.4% of all the patients. 48 patients were associated myopia, 30 patients with hyperopia, 43 patients with strabismus. Among them, 153 cases of compensatory head position direction were horizontal with face turn, 43 cases (43/153, 28.1%) showed face turning to the left, 110 cases (110/153, 71.9%) showed face turning to the right. Surgeries were designed according to the compensatory head position and head retroversion angle. For 15 patients with double intermediate zones, the position which was often used with good visual function was chosen for operation design. As for the patients with nystagmus and strabismus, the transfer null zone to primary position for the dominant eye and strabismus surgery for the other eye was chosen. And for complicated patients with compensative head position, the dominant head posture were designed for surgery. CONCLUSIONS: ICN is dominated by male with variable clinical manifestations. Surgical choice for ICN depends on the direction of head position and if there is strabismus accompanying it.The aim of ocular muscle surgery is to transfer null zone to primary position. (Chin J Ophthalmol, 2016, 52: 574-578).

Clínica y diagnóstico de la enfermedad de Pelizaeus-Merzbacher: descripción de cinco casos / Clinical features and diagnosis of Pelizaeus-Merzbacher disease: five case reports

Introducción. La enfermedad de Pelizaeus-Merzbacher es un trastorno hipomielinizante raro debido a alteraciones en el gen PLP1, que lleva a un fallo de la mielinización axonal de los oligodendrocitos en el sistema nervioso central. Existen dos formas descritas según la gravedad de su presentación: connatal y clásica. Se caracteriza por hipotonía neonatal, retraso del desarrollo psicomotor, espasticidad progresiva de predominio en los miembros inferiores y nistagmo, con signos y síntomas piramidales y extrapiramidales, y la forma connatal es mucho más grave. La resonancia magnética muestra leucoencefalopatía hipomielinizante difusa, los potenciales evocados usualmente se alteran y la confirmación se realiza mediante estudio molecular del gen PLP1. Casos clínicos. Se presentan cinco pacientes pediátricos afectados, cuatro con la forma clásica y uno con la forma connatal; se describen las características clínicas, los estudios complementarios y se realiza una revisión concisa de la bibliografía. Conclusión. Esta enfermedad tiene una evolución progresiva y casi invariable, lo cual es la clave clínica para diferenciarla de otras entidades como la parálisis cerebral infantil, neuropatías periféricas, esclerosis múltiple, entre otras, además de los hallazgos característicos en las neuroimágenes. Es necesario sospechar este diagnóstico y confirmar alteraciones en el gen PLP1 con el fin de obtener una incidencia real de esta entidad, probablemente subestimada, como otras leucodistrofias (AU)

Introduction. Pelizaeus-Merzbacher disease is an infrequent hypomyelinating disorder caused by alterations in the PLP1 gene, which leads to a fault in the axonal myelination of the oligodendrocytes in the central nervous system. Two forms have been reported, according to the severity of the presentation: connatal and classic. It is characterised by neonatal hypotonia, delayed psychomotor development, progressive spasticity predominantly in the lower limbs and nystagmus, with pyramidal and extrapyramidal signs and symptoms; the connatal form is far more severe. Magnetic resonance imaging shows diffuse hypomyelinating leukoencephalopathy, evoked potentials are usually altered and confirmation is obtained through a molecular study of the PLP1 gene. Case reports. We present the cases of five paediatric patients, four of whom had the classic form and one with the connatal form. The clinical characteristics and complementary studies are described, and a concise review of the literature is carried out. Conclusion. This disease has a progressive and almost unvarying course, which is the clinical key to be able to differentiate it from other entities such as infantile cerebral palsy, peripheral neuropathies or multiple sclerosis, among others, in addition to the characteristic neuroimaging findings. It is necessary to suspect this diagnosis and confirm alterations in the PLP1 gene with the aim of obtaining a real incidence of this entity, which is probably underestimated, like other leukodystrophies (AU)

[Thickening or hypoplasia of the fovea]. / Verdickung oder Hypoplasie der Fovea.

A 64-year-old female patient complained of a bilateral reduction in vision. The foveal reflex was remarkable bilaterally and optical coherence tomography (OCT) demonstrated the absence of a foveal depression. After exclusion of possible diseases foveal hypoplasia was diagnosed. This rare alteration of the fovea should not be mistaken for foveal edema. A volume scan with a narrow grid is advisable to avoid a misinterpretation.

Delayed Diagnosis of Enhancing Posterior Fossa Tumors Mimicking the Tela Choroidea of the Fourth Ventricle.

BACKGROUND: Posterior fossa brain tumors are common in children. Symptoms typically develop when the tumors have reached sufficient size to cause compression of adjacent neural structures or cause obstructive hydrocephalus. Many tumors in this region originate from the tela choroidea and choroid plexus of the fourth ventricle. Enhancement of the fourth ventricular tela choroidea and choroid plexus is uncommon in children, and when such enhancement is present, it may represent early tumor growth. METHODS: A 5-year-old girl with a history of congenital nystagmus, for whom initial work-up was reported as negative, presented again several years later with headache, nausea, and vomiting. She was found to have a large posterior fossa lesion on repeat neuroimaging that was retrospectively seen on the first neuroimaging scan as prominent enhancement in the region of the fourth ventricular choroid plexus. The second patient presented with congenital nystagmus and a lingual tremor and was found to have a slowly growing lesion situated in the fourth ventricle. Initial imaging was read as nodularly enhancing tela choroidea, but subsequent scans revealed enlargement of the lesion. RESULTS: The first patient underwent gross total resection, and neuropathology was consistent with an atypical teratoid rhabdoid tumor. The patient has done well with postoperative adjuvant therapies. In the second patient, resection of the lesion revealed ependymoma; the patient has done well after adjuvant radiation therapy. CONCLUSIONS: Pediatric patients who have enhancing tela choroidea or choroid plexus without an obvious mass lesion of the fourth ventricle may harbor early tumors. Surveillance imaging in these patients may be warranted given the aggressive nature of certain posterior fossa tumors in children. Failure to recognize abnormal enhancement patterns in this region may lead to delayed diagnosis.

Mutational analysis and genotype-phenotype correlations in southern Indian patients with sporadic and familial aniridia.

PURPOSE: Aniridia is a rare panocular disorder characterized by iris hypoplasia and other associated eye anomalies. Heterozygous null mutations in paired box gene 6 (PAX6) are the major cause of the classic aniridia phenotype. This study aims to detect the mutational spectrum of PAX6 and associated phenotypes in southern Indian patients with sporadic and familial aniridia. METHODS: Genomic DNA was isolated from peripheral blood from all participants. The coding regions and flanking intronic sequences of PAX6 were screened with Sanger sequencing in 30 probands with aniridia. The identified variations were further evaluated in available family members and 150 healthy controls. The pathogenic potential of the mutations were assessed using bioinformatics tools. RESULTS: Thirteen different mutations were detected in eight sporadic and five familial cases. Eleven novel mutations, including five insertions (c.7_10dupAACA, c.567dupC, c.704dupC, c.868dupA and c.753_754insTA), two deletions (c.242delC and c.249delT), and four splicing variants (c.10+1G>A, c.141G>A, c.141+4A>G and c.764A>G) were identified in this study. Clinical findings of the patients revealed phenotypic heterogeneity with the same or different mutations. CONCLUSIONS: This study reported 11 novel mutations and thus expanded the spectrum of PAX6 mutations. Interestingly, all mutations reported in this study were truncations, which confirms the hypothesis that haploinsufficiency of PAX6 causes the aniridia phenotype. Our observations revealed inter- and intrafamilial phenotypic variability with PAX6 mutations. The common ocular findings associated with PAX6 mutations were iris hypoplasia, nystagmus, and foveal hypoplasia reported in almost all cases, with cataract, glaucoma, and keratopathy reported in approximately 50% of the patients.

ANOMALOUS HEAD POSTURES IN STRABISMUS AND NYSTAGMUS DIAGNOSIS AND MANAGEMENT.

UNLABELLED: Abnormal head positions are adopted in order to improve visual acuity, to avoid diplopia or to obtain a more comfortable binocular vision. The head can be turned or tilted toward right or left, with the chin rotated up or downwards or combination of these positions. The ophthalmologic examination including the assessment of versions leads to the diagnosis. When versions are free, the cause may be congenital nystagmus or strabismus with large angle. When versions are limited we suspect paralytic or restrictive strabismus. The head tilted to one shoulder suggests cyclotropia (IV Nerve Palsy) or congenital nystagmus. We present few of the above cases. An adequate surgical treatment can improve or correct the ocular deviation, diplopia and the abnormal head posture. CONCLUSIONS: The abnormal head posture must be assessed and treated early in order to correct the ocular position and head posture. All patient presenting abnormal head position HAD TO BE investigated by an ophthalmologist.

Prevalence and causes of visual impairment and rate of wearing spectacles in schools for children of migrant workers in Shanghai, China.

BACKGROUND: To assess the prevalence of visual impairment and rate of wearing spectacles in schools for children of migrant workers in Shanghai, China. METHODS: Children from grade 1 to 5 in schools for children of migrant workers were randomly chosen for ocular examinations. All children were screened for uncorrected visual acuity and presenting visual acuity. After screening, the children whose uncorrected visual acuity was 20/40 or less received ocular motility evaluation, cycloplegic refraction/non-cycloplegic refraction, and external eye, anterior segment, media, and fundus examinations. RESULTS: A total of 9673 children were enumerated and 9512 (98.34%) participated in this study. The prevalence of uncorrected, presenting, and best-corrected visual acuity of 20/40 or worse in the better eye were 13.33%, 11.26%, and 0.63%, respectively. The rate of wearing spectacles of the children with visual impairment in one or both eyes was 15.50%. Of these, 26.05% were wearing spectacles with inaccurate prescriptions. Refractive error was a major cause of visual impairment, accounting for 89.48% of all the visual impairment causes. Other causes of visual impairment included amblyopia accounting for 10.12%; congenital cataract, 0.1%; congenital nystagmus, 0.1%; ocular prosthesis, 0.1%; macular degeneration, 0.05%; and opaque cornea, 0.05%. CONCLUSIONS: This is the first study of the prevalence and causes of visual impairment in schools for children of migrant workers in Shanghai, China. The visual impairment rate in schools for children of migrant workers in suburbs of Shanghai in the best eye before vision correction was lower than those of urban children in mainstream schools in Guangzhou in 2012, and higher than students in rural of Beijing in 1998 and in suburb of Chongqing in 2007. The refractive error was the principal cause of the visual impairment of the children of migrant workers. The rate of wearing spectacles was low and the percentage of inaccurate prescriptions, among those who wore spectacles, was high. Uncorrected refractive error was a significant cause of visual impairment in migrant children.

A novel mutation of PAX6 identified in a Chinese twin family with congenital aniridia complicated with nystagmus.

Genetic variations within the paired box gene 6 (PAX6) gene are associated with congenital aniridia. To detect the genetic defects in a Chinese twin family with congenital aniridia and nystagmus, exons of PAX6 were amplified by polymerase chain reaction (PCR), sequenced and compared with a reference database. Six members from the family of three generations were included in the study. The twins' father presented with congenital aniridia, nystagmus and cataract at birth, while the twins presented with congenital aniridia and nystagmus. A novel mutation c.888 insA in exon 10 of PAX6 was identified in all affected individuals. This study suggests that the novel mutation c.888 insA is likely responsible for the pathogenesis of the congenital aniridia and nystagmus in this pedigree. To the best of our knowledge, this is the first report of this mutation in PAX6 gene in pedigree with aniridia. Furthermore, no PAX6 gene defect was reported in twins with congenital aniridia.

Longitudinal study of spherical refractive error in infantile nystagmus syndrome.

PURPOSE: To explore the onset and progression of spherical refractive error in a population with infantile nystagmus syndrome. METHODS: Retrospective refractive error data were obtained from 147 medical records of children with infantile nystagmus syndrome (albinism n = 98; idiopathic infantile nystagmus n = 49), attending a low vision clinic in Northern Ireland, over a 24 year period (1986-2010). Data were categorised by age to allow for comparisons with published studies. A prospective group of participants with Infantile nystagmus syndrome (INS) [n = 22 (albinism n = 18, idiopathic infantile nystagmus n = 4)] (aged 0-4) were also recruited. Cycloplegic streak retinoscopy was performed biannually, over a 3 year period. Spherical equivalent refractive error and most ametropic meridian were analysed. RESULTS: The mean spherical equivalent refractive errors for albinism and idiopathic infantile nystagmus groups (across all age categories) were hypermetropic, with highest levels demonstrated by the participants with albinism aged 1 ≤ 4 years (Mann-Whitney U test, p = 0.013). Mean most ametropic meridian was highest in the albinism group aged 1 ≤ 12 years (Mann-Whitney U test, p < 0.05). Individual data demonstrated relatively static spherical equivalent refractive errors over time. Prospective participants were hypermetropic at all visits and those with albinism had, on average, higher refractive errors than those with idiopathic infantile nystagmus (IIN). No significant correlations were noted between visual acuity and spherical equivalent refractive errors or most ametropic meridian. CONCLUSIONS: Hypermetropia is the most prevalent spherical refractive error in the INS population, irrespective of level of visual acuity. Individuals with infantile nystagmus syndrome fail to demonstrate typical patterns of emmetropisation, particularly in the presence of albinism.

Infantile nystagmus and visual deprivation: foveal instability and refractive development in a low vision register series.

PURPOSE: To evaluate whether effects of early foveal motor instability due to infantile nystagmus might compare to those of experimental visual deprivation on refraction in a childhood series. METHODS: This was a retrospective analysis of data from the Danish Register for Blind and Weaksighted Children with infantile nystagmus recorded as prime diagnosis. We perused 90 records of children now aged 10-17 years, some of whom eventually exceeded the register borderline of 0.3 as best-corrected visual acuity. Spherical equivalent refraction was the primary outcome parameter, but visual acuity, astigmatism, and age were further considered. The series comprised 48 children with nystagmus as single diagnosis, whereas 42 had clinical colabels (Down syndrome [13], dysmaturity [9], and mental retardation, encephalopathy [20]). RESULTS: Median binocular visual acuity was 0.3 in the full series, and median refraction was emmetropia in all subgroups. Compared with Danish control data, myopia was over-represented, and generally of juvenile onset. The Down syndrome subgroup was separated from the remainder by an even higher myopia prevalence. Astigmatism above 1 D cylinder value was recorded in 52% of all cases. CONCLUSIONS: The prevalence of myopia and astigmatism was higher among children with nystagmus than in controls. Myopia was mainly juvenile, and not related to the period of infancy when the motor foveal smear is considered most disturbing and possibly influencing visual development.

Isolated foveal hypoplasia with secondary nystagmus and low vision is associated with a homozygous SLC38A8 mutation.

Foveal hypoplasia, always accompanied by nystagmus, is found as part of the clinical spectrum of various eye disorders such as aniridia, albinism and achromatopsia. However, the molecular basis of isolated autosomal recessive foveal hypoplasia is yet unknown. Individuals of apparently unrelated non consanguineous Israeli families of Jewish Indian (Mumbai) ancestry presented with isolated foveal hypoplasia associated with congenital nystagmus and reduced visual acuity. Genome-wide homozygosity mapping followed by fine mapping defined a 830 Kb disease-associated locus (LOD score 3.5). Whole-exome sequencing identified a single missense mutation in the homozygosity region: c.95T>G, p.(Ile32Ser), in a conserved amino acid within the first predicted transmembrane domain of SLC38A8. The mutation fully segregated with the disease-associated phenotype, demonstrating an ∼10% carrier rate in Mumbai Jews. SLC38A8 encodes a putative sodium-dependent amino-acid/proton antiporter, which we showed to be expressed solely in the eye. Thus, a homozygous SLC38A8 mutation likely underlies isolated foveal hypoplasia.