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Middle East African Journal of... 2013The purpose of this report is to summarize an understanding of the ocular motor system in patients with albinism. Other than the association of vertical eccentric gaze...
The purpose of this report is to summarize an understanding of the ocular motor system in patients with albinism. Other than the association of vertical eccentric gaze null positions and asymmetric, (a) periodic alternating nystagmus in a large percentage of patients, the ocular motor system in human albinism does not contain unique pathology, rather has "typical" types of infantile ocular oscillations and binocular disorders. Both the ocular motor and afferent visual system are affected to varying degrees in patients with albinism, thus, combined treatment of both systems will maximize visual function.
Topics: Albinism, Ocular; Albinism, Oculocutaneous; Eye Movements; Humans; Nystagmus, Pathologic; Oculomotor Nerve
PubMed: 24014991
DOI: 10.4103/0974-9233.114804 -
Ophthalmic Genetics Dec 2021Ocular albinism type I (OA1) is caused by mutations in the gene. The purpose of this study was to describe the clinical and genetic findings in 13 patients from 12...
PURPOSE
Ocular albinism type I (OA1) is caused by mutations in the gene. The purpose of this study was to describe the clinical and genetic findings in 13 patients from 12 unrelated Chinese pedigrees with a pathogenic variant of the gene.
METHODS
Most patients underwent clinical examination, including best-corrected visual acuity (BCVA), slit-lamp biomicroscopy, fundus examination, spectral domain optical coherence tomography, and full-field electroretinograms (ERG). A combination of molecular screening procedures, consisting of Sanger-DNA sequencing of and targeted next-generation sequencing, was performed to identify each mutation. In silico programs were utilized to evaluate the pathogenicity of all the variants.
RESULTS
The 13 patients (mean age 21.75 ± 16.63 years, range 1-54 years) all presented with congenital nystagmus, different extents of visual impairment, and severe foveal hypoplasia. Their BCVA was between 0.05 and 0.3 (decimal notation). The patients and obligate carriers exhibited different extents of mild depigmentation of the iris and fundus. We detected 11 distinct mutations in this patient cohort, including 7 novel mutations. Most (82%) were null mutations and included frameshift indel, nonsense, splicing effect, and large genomic DNA deletions, while missense mutations only accounted for 18%.
CONCLUSIONS
Patients with mutations all have congenital nystagmus, visual impairment, and foveal hypoplasia, whereas hypopigmentation in their iris and fundus is mild. They exhibit no evident genotype-phenotype correlations. mutation screening is very important for establishing a precise diagnosis and for providing genetic counseling for patients and their families.
Topics: Adolescent; Adult; Albinism, Ocular; Albinism, Oculocutaneous; Asian People; Child; Child, Preschool; China; Cross-Sectional Studies; Electroretinography; Eye Proteins; Female; Genetic Association Studies; High-Throughput Nucleotide Sequencing; Humans; Infant; Male; Membrane Glycoproteins; Middle Aged; Mutation; Nystagmus, Congenital; Pedigree; Retina; Retrospective Studies; Slit Lamp Microscopy; Tomography, Optical Coherence; Visual Acuity
PubMed: 34346269
DOI: 10.1080/13816810.2021.1958352 -
Transactions of the American... 1996The purpose of this investigation was to study vision in albinism from 3 perspectives: first, to determine the characteristics of grating acuity development in children... (Comparative Study)
Comparative Study
PURPOSE
The purpose of this investigation was to study vision in albinism from 3 perspectives: first, to determine the characteristics of grating acuity development in children with albinism; second, to study the effect of illumination on grating acuity; and third, to define the effect of melanin pigment in the macula on visual acuity.
METHODS
I. Binocular and monocular grating acuity was measured with the acuity card procedure in 40 children with albinism during the first 3 years of life. Recognition acuity was eventually measured in 27 of these patients. Ocular pigment was documented by a previously established method of grading iris transillumination and macular transparency. II. Grating acuity under standard and increased illumination levels was measured in 20 adults with albinism (group I) compared with that in 20 adults with nystagmus due to conditions other than albinism (group II) and 20 adults without ocular abnormalities (group III). Recognition acuity measured with the ETDRS charts was also recorded for each group. III. Best-corrected binocular acuity was measured in 29 patients with albinism who were identified with melanin pigment in their maculas by direct ophthalmoscopy.
RESULTS
I. Both binocular and monocular grating acuity was reduced 2 to 3 octaves below the norm for ages 6 months to 3 years. Limited data available in the first 6 months of life did not show failure of vision to develop. Grating acuity measurements overestimated eventual recognition acuity. Mean recognition acuity was 20/111. A relationship between grating acuity development and presence or absence of ocular pigment was not found. II. Grating acuity was significantly better for groups I and II under the condition of increased illumination (P < .03). For patients with albinism, grating acuity under standard illumination was significantly better than recognition acuity (P < .001). For all groups, grating acuity under increased illumination was significantly better than recognition acuity (P < .01). III. Mean recognition acuity in patients with albinism and melanin pigment in their maculas (20/47) was significantly better than measured recognition acuity in Project I (P < .001). All had foveal hypoplasia, but 8 patients had an incompletely developed annular reflex in the macula, 6 patients showed stereoacuity, and 3 patients had no nystagmus.
CONCLUSIONS
I. Grating acuity development in albinism seems to progress along a curve that is asymptotic to visual development in a normal population. II. Increasing illumination does not reduce grating acuity in patients with albinism. Grating acuity overestimates recognition acuity in these patients. III. Ophthalmoscopic detection of melanin pigment in the macula in patients with albinism is associated with better vision.
Topics: Adolescent; Adult; Albinism, Ocular; Albinism, Oculocutaneous; Child; Child, Preschool; Evoked Potentials, Visual; Female; Fundus Oculi; Humans; Infant; Light; Macula Lutea; Male; Melanins; Middle Aged; Nystagmus, Pathologic; Vision, Binocular; Vision, Ocular; Visual Acuity
PubMed: 8981720
DOI: No ID Found -
Current Opinion in Ophthalmology Dec 1994Articles published during the past year on the ocular manifestations of metabolic diseases and related issues are reviewed. The focus is on clarifying the genetic or... (Review)
Review
Articles published during the past year on the ocular manifestations of metabolic diseases and related issues are reviewed. The focus is on clarifying the genetic or molecular basis of various metabolic disorders. Mutations of the P gene were reported in tyrosinase-positive oculocutaneous albinism and autosomal recessive ocular albinism, and were associated with a wide range of clinical phenotypes. This finding should aid in more accurate diagnosis and facilitate genetic counseling. There is no consensus but the horizontal supranuclear gaze palsy in Gaucher's disease may aid in subtyping. The report of a family with Morquio syndrome suggests that lenticular opacities should be considered as an additional finding in this syndrome. Patients with nephropathic cystinosis, which had been a fatal disease in childhood, are now surviving to adulthood. Serious ocular complications were described in adults.
Topics: Amino Acids; Carbohydrate Metabolism; Eye Diseases; Humans; Lipid Metabolism; Lipoproteins; Lysosomes; Metabolic Diseases
PubMed: 10150832
DOI: 10.1097/00055735-199412000-00013 -
Genes Jan 2023The diagnostic yield of genetic testing for ocular/oculocutaneous albinism (OA/OCA) in a diverse pediatric population in the United States (U.S.) is unclear. Phenotypes...
The diagnostic yield of genetic testing for ocular/oculocutaneous albinism (OA/OCA) in a diverse pediatric population in the United States (U.S.) is unclear. Phenotypes of 53 patients who presented between 2006-2022 with OA/OCA were retrospectively correlated with genetic testing results. Genetic diagnostic yield was defined as detection of pathogenic/likely pathogenic variant(s) matching the anticipated inheritance for that gene-disease relationship. Variant reclassifications of those with variants of uncertain significance (VUS) and without positive diagnostic yield were completed. Overall initial genetic diagnostic yield of OA/OCA was 66%. There was no significant difference ( = 0.59) between race and ethnicities (Black (78%), White (59%), Hispanic/Latino (64%)); however, the diagnostic yield of OA (33%) was significantly lower ( = 0.007) than OCA (76%). Causative variants in (28%) and (20%) were most common. Further, Hermansky-Pudlak syndrome variants were identified in 9% of patients. Re-classification of VUS in non-diagnostic cases resulted in genetic diagnoses for 29% of individuals and increased overall diagnostic yield to 70% of all subjects. There is a high diagnostic yield of genetic testing of patients overall with OA/OCA in a diverse U.S. based pediatric population. Presence or absence of cutaneous involvement of albinism significantly affects genetic diagnostic yield.
Topics: Child; Humans; Retrospective Studies; Mutation; Membrane Transport Proteins; Genetic Testing; Albinism, Ocular; Hermanski-Pudlak Syndrome
PubMed: 36672876
DOI: 10.3390/genes14010135 -
Ophthalmic Paediatrics and Genetics Jun 1992Genetic, clinical and electrophysiological aspects of albinism are described. Emphasis is placed on electrophysiological features which help to distinguish albinism from... (Review)
Review
Genetic, clinical and electrophysiological aspects of albinism are described. Emphasis is placed on electrophysiological features which help to distinguish albinism from other clinical conditions, and on stimulating and recording factors which can affect the clarity of VEP results.
Topics: Albinism, Ocular; Electroretinography; Evoked Potentials, Visual; Humans; Nystagmus, Pathologic
PubMed: 1495771
DOI: 10.3109/13816819209087609 -
Journal of the American Optometric... Jan 1991Albinism is inherited as autosomal recessive, with one exception: Ocular albinism, which has an x-linked trait. Visual symptoms include photophobia, varying degrees of... (Review)
Review
Albinism is inherited as autosomal recessive, with one exception: Ocular albinism, which has an x-linked trait. Visual symptoms include photophobia, varying degrees of nystagmus, reduction in visual acuity from 20/30 to 20/400 and varying degrees of moderate to high amounts of corneal astigmatism. Albinism patients respond very well to low vision devices and glare filters.
Topics: Albinism, Ocular; Albinism, Oculocutaneous; Eyeglasses; Humans; Sensory Aids; Vision, Low
PubMed: 1813496
DOI: No ID Found -
Journal of AAPOS : the Official... Feb 2011Albinism is a group of disorders characterized principally by its ophthalmic features with or without systemic manifestations. Persons with albinism manifest a wide... (Review)
Review
Albinism is a group of disorders characterized principally by its ophthalmic features with or without systemic manifestations. Persons with albinism manifest a wide variety of phenotypes and limited number of genotypes. Modern molecular genetics has encouraged a new classification and understanding of the subtypes of these disorders. In addition to the ocular and systemic manifestations, ophthalmologists must be familiar with the specific visual needs and psychological challenges of these individuals as well as those of their families.
Topics: Albinism, Ocular; Albinism, Oculocutaneous; Genotype; Humans; Phenotype; Terminology as Topic
PubMed: 21397808
DOI: 10.1016/j.jaapos.2010.10.012 -
Journal of AAPOS : the Official... Feb 2011
Topics: Albinism, Ocular; Albinism, Oculocutaneous; Humans
PubMed: 21397796
DOI: 10.1016/j.jaapos.2011.01.002 -
Pigment Cell & Melanoma Research Jul 2021Oculocutaneous albinism (OCA) is the most frequent presentation of albinism, a heterogeneous rare genetic condition generally associated with variable alterations in... (Review)
Review
Oculocutaneous albinism (OCA) is the most frequent presentation of albinism, a heterogeneous rare genetic condition generally associated with variable alterations in pigmentation and with a profound visual impairment. There are non-syndromic and syndromic types of OCA, depending on whether the gene product affected impairs essentially the function of melanosomes or, in addition, that of other lysosome-related organelles (LROs), respectively. Syndromic OCA can be more severe and associated with additional systemic consequences, beyond pigmentation and vision alterations. In addition to OCA, albinism can also be presented without obvious skin and hair pigmentation alterations, in ocular albinism (OA), and a related genetic condition known as foveal hypoplasia, optic nerve decussation defects, and anterior segment dysgenesis (FHONDA). In this review, we will focus only in the genetics of skin pigmentation in OCA, both in human and mouse, updating our current knowledge on this subject.
Topics: Albinism, Oculocutaneous; Animals; Disease Models, Animal; Genetic Predisposition to Disease; Humans; Melanins; Mice; Syndrome
PubMed: 33960688
DOI: 10.1111/pcmr.12982