-
Children (Basel, Switzerland) Dec 2023(1) Background: The aim of the study was to describe refractive development from early childhood to adulthood in Danish patients with albinism and to evaluate the effect...
(1) Background: The aim of the study was to describe refractive development from early childhood to adulthood in Danish patients with albinism and to evaluate the effect of foveal developmental stage on refractive development; (2) Methods: Patients with a clinical diagnosis of ocular or oculocutaneous albinism were invited for a refractive evaluation and comprehensive phenotyping including macular optical coherence tomography (OCT) scans. Foveal hypoplasia was graded based on OCT from 0 (normal) to 4 (absence of any signs of foveal specialization). Medical files were reviewed for historical refractive values in individual patients; (3) Results: Hyperopia (spherical equivalent refraction (SEQ) of ≥+1 Diopter (D)) was common in both children (81.3%) and adults (67.1%). The lower prevalence of hyperopia in adults was predominantly explained by increasing astigmatism with age. Emmetropization (>2D change from before 3 years to adolescence) was seen in 22.2%. There was no influence on foveal hypoplasia grade on the degree of refractive errors throughout life; (4) Conclusions: We found that emmetropization was uncommon in Danish patients with albinism and that the degree of foveal developmental stage did not influence emmetropization or the distribution of refractive errors. High degrees of hyperopia and astigmatism were common. These results indicate that fear of impeding emmetropization should not refrain the clinician from providing adequate correction for refractive errors in young children with albinism.
PubMed: 38136112
DOI: 10.3390/children10121910 -
Investigative Ophthalmology & Visual... Dec 2023The purpose of this study was to describe the association among nystagmus characteristics, foveal hypoplasia, and visual acuity in patients with albinism.
PURPOSE
The purpose of this study was to describe the association among nystagmus characteristics, foveal hypoplasia, and visual acuity in patients with albinism.
METHODS
We studied nystagmus recordings of 50 patients with albinism. The nystagmus waveform was decomposed into two types: dominantly pendular and dominantly jerk. We correlated the nystagmus type, amplitude, frequency, and percentage of low velocity (PLOV) to Snellen visual acuity and foveal hypoplasia grades.
RESULTS
The grade of foveal hypoplasia and visual acuity showed a strong correlation (r = 0.87, P < 0.0001). Nystagmus type and PLOV had the strongest significant (P < 0.0001) correlation with visual acuity (r = 0.70 and r = -0.56, respectively) and with foveal hypoplasia (r = 0.76 and r = -0.60, respectively). Patients with pendular nystagmus type had the lowest PLOV, and the highest grade of foveal hypoplasia (P < 0.0001). Severe foveal hypoplasia (grade 4), was almost invariably associated with pendular nystagmus (86%).
CONCLUSIONS
Foveal hypoplasia grade 4 is associated with pendular nystagmus, lower PLOV, and worse visual acuity. Based on these results, nystagmus recordings at a young age may contribute to predicting visual outcomes.
Topics: Humans; Eye Abnormalities; Albinism, Oculocutaneous; Fovea Centralis; Tomography, Optical Coherence; Nystagmus, Pathologic; Vision Disorders; Visual Acuity; Albinism
PubMed: 38133506
DOI: 10.1167/iovs.64.15.30 -
Scientific Reports Dec 2023Plants with partial or complete loss of chlorophylls and other pigments are frequently occurring in nature but not commonly found. In the present study, we characterize...
Plants with partial or complete loss of chlorophylls and other pigments are frequently occurring in nature but not commonly found. In the present study, we characterize a leaf color mutant 'arly01' with an albino stripe in the middle of the leaf, which is an uncommon ornamental trait in Anoectochilus roxburghii. The albino "mutant" middle portion and green "normal" leaf parts were observed by transmission electron microscopy (TEM), and their pigment contents were determined. The mutant portion exhibited underdevelopment of plastids and had reduced chlorophyll and other pigment (carotenoid, anthocyanin, and flavonoid) content compared to the normal portion. Meanwhile, comparative transcript analysis and metabolic pathways mapping showed that a total of 599 differentially expressed genes were mapped to 78 KEGG pathways, most of which were down-regulated in the mutant portion. The five most affected metabolic pathways were determined to be oxidative phosphorylation, photosynthesis system, carbon fixation & starch and sucrose metabolism, porphyrin and chlorophyll metabolism, and flavonoid biosynthesis. Our findings suggested that the mutant 'arly01' was a partial albinism of A. roxburghii, characterized by the underdevelopment of chloroplasts, low contents of photosynthetic and other color pigments, and a number of down-regulated genes and metabolites. With the emergence of ornamental A. roxburghii in southern China, 'arly01' could become a popular cultivar due to its unique aesthetics.
Topics: Gene Expression Profiling; Chlorophyll; Chromosome Mapping; Flavonoids; Plant Leaves; Transcriptome; Gene Expression Regulation, Plant; Color
PubMed: 38123722
DOI: 10.1038/s41598-023-50352-5 -
Genetics and Molecular Biology 2023Oculocutaneous albinism (OCA) is a heterogeneous group of genetic disorders involving deficiencies in melanin biosynthesis, with consequent skin, hair, and eye...
Oculocutaneous albinism (OCA) is a heterogeneous group of genetic disorders involving deficiencies in melanin biosynthesis, with consequent skin, hair, and eye hypopigmentation. The world prevalence is estimated at 1/17,000, but there is high variability among populations. The affected individuals, besides clinical complications, can suffer from discrimination. The Brazilian population is highly admixed, with isolated and inbred communities. Previous reports indicated the presence of diverse isolated communities with a high prevalence of OCA in Brazil. The present work sought to review and characterize clusters of albinism in this country based on scientific literature search, newspapers, and websites. We identified and characterized 18 clusters, 13 confirmed by scientific studies. Seven clusters are in the Northeast region, with predominant African ancestry, and seven others in indigenous communities, particularly among the Kaingaing in South Brazil. Isolation and inbreeding associated with founder effects seem to be the most plausible explanation. Molecular studies and clinical classification are still limited. Their localization in deprived regions with poor infrastructure makes them particularly vulnerable to the social and clinical consequences of lacking melanin. We reinforce the need for a tailored approach to these communities, including appropriate medical care, social support, and genetic counselling.
PubMed: 38113291
DOI: 10.1590/1678-4685-GMB-2023-0164 -
Cureus Nov 2023Chediak-Higashi syndrome (CHS) is a congenital immunodeficiency disorder characterized by recurrent bacterial infections, oculocutaneous albinism, and abnormal...
Chediak-Higashi syndrome (CHS) is a congenital immunodeficiency disorder characterized by recurrent bacterial infections, oculocutaneous albinism, and abnormal intracellular protein transport. The incidence of CHS is rare, with approximately 500 cases reported so far. One of the key immunological features of CHS is neutropenia. The management of CHS includes supportive treatment, chemotherapy, methylprednisolone, IL-2 administration, and hematopoietic stem cell transplantation (HSCT). However, neutropenia can persist even after these treatments. This case report presents the successful management of severe neutropenia in an 8-year-old girl diagnosed with CHS. The patient exhibited classic CHS features, including hypopigmentation and recurrent infections. Initial treatment with antibiotics led to the resolution of the fever, but severe neutropenia persisted. Granulocyte-colony stimulating factor (G-CSF) therapy was initiated, which resulted in a substantial increase in the absolute neutrophil count (ANC) with no adverse effects. Throughout treatment with G-CSF, the patient remained stable. The patient was finally referred to the tertiary care center for consideration of bone marrow transplantation. This case highlights the potential safety and efficacy of G-CSF in managing CHS-associated neutropenia.
PubMed: 38111422
DOI: 10.7759/cureus.49010 -
Annals of Medicine and Surgery (2012) Dec 2023Lymphangiomatosis is a rare abnormal proliferation of lymphatic vessels involving multiple organs like the brain, lung, heart, spleen, liver, and bones. Lymphangiomas...
INTRODUCTION
Lymphangiomatosis is a rare abnormal proliferation of lymphatic vessels involving multiple organs like the brain, lung, heart, spleen, liver, and bones. Lymphangiomas constitute 5.6% of all benign tumors in infancy and adulthood.
CASE PRESENTATION
We report a case of a young lady who presented with constitutional symptoms and progressive dyspnea. Her medical history is significant for muco-cutaneous albinism, diffuse hemangiomas of the bone and viscera, and consumptive coagulopathy status post-splenectomy. After initial investigations, she was found to have right-sided pleural effusion. Pleural fluid analysis indicated chylothorax. She had multiple drainages of the pleural fluid done, and afterward, ligation of the right thoracic duct was performed with a trial of sirolimus, which improved her chylothorax.
CLINICAL DISCUSSION
Several case reports have reported positive outcomes with sirolimus in the treatment of lymphangiomatosis. However, larger controlled studies are needed to confirm these findings.
CONCLUSION
Sirolimus is promising as a medical treatment for diffuse pulmonary lymphangiomatosis.
PubMed: 38098585
DOI: 10.1097/MS9.0000000000001384 -
Ophthalmic Research 2024Hermansky-Pudlak syndrome (HPS) is a rare autosomal-recessive disease characterized by ocular albinism (OA) or oculocutaneous albinism (OCA), platelet dysfunction, and...
INTRODUCTION
Hermansky-Pudlak syndrome (HPS) is a rare autosomal-recessive disease characterized by ocular albinism (OA) or oculocutaneous albinism (OCA), platelet dysfunction, and other symptoms. This study aimed to analyze the molecular defect in two Chinese families with suspected OA, as well as to investigate the profile of HPS6 variants and their genotype-phenotype correlations.
METHODS
Seven members from two families were recruited and underwent clinical ophthalmologic examinations. The genomic DNA was extracted from peripheral blood leukocytes. Whole-exome sequencing was performed on the proband of family JX. The single coding exon of HPS6 was directly Sanger sequenced based on PCR amplification in all available family members. An additional 46 probands from families or sporadic cases with the pathogenic variants of HPS6 reported in the literature were reviewed.
RESULTS
We identified two different compound heterozygous truncating variants of HPS6 in probands with suspected OA from two independent families. The proband of family JX had c.1674dup and c.503-504del variants, and the other proband from family CZ had a nonsense variant of c.1114C>T and a frameshift variant of c.1556del. Among them, c.1674dup and c.1556del variants in HPS6 have not been reported previously. Therefore, our patients were diagnosed as HPS6 disease by molecular diagnostics. In the retrospective cohort of HPS6 patients, we delineated the profile of HPS6 variants and revealed a significant overlap between CpG islands and the variants of HPS6, suggesting a potential link between DNA methylation and HPS6 variants. We also observed a spatial aggregation of the variants in 3D structure of HPS6 protein, implying the possible functional significance of these structural regions. In addition, we did not find any significant genotype-phenotype correlation of HPS6, and neither did we observe a correlation between the truncation length of the HPS6 protein and the phenotype of HPS6 disease.
CONCLUSION
Our research expands the spectrum of HPS6 variants, providing a comprehensive delineation of their profile and systematically investigating genotype-phenotype correlations in HPS6. These findings could offer potentially valuable clues for investigating the molecular mechanism underlying HPS6 pathogenesis, as well as aiding the clinical diagnosis of HPS6 patients and improving disease prognosis.
Topics: Humans; Albinism, Ocular; Retrospective Studies; Hermanski-Pudlak Syndrome; Phenotype; Proteins; Mutation; Pedigree; Intracellular Signaling Peptides and Proteins
PubMed: 38091959
DOI: 10.1159/000535788 -
Investigative Ophthalmology & Visual... Nov 2023Perception of the motion quartet (MQ) alternates between horizontal and vertical motion, with a bias toward vertical motion. This vertical bias has been explained by the...
PURPOSE
Perception of the motion quartet (MQ) alternates between horizontal and vertical motion, with a bias toward vertical motion. This vertical bias has been explained by the dominance of intrahemispheric processing. In albinism, each hemisphere receives input from both visual hemifields owing to enhanced crossing of the optic nerves at the optic chiasm. This might affect the perception of the ambiguous MQ and particularly the vertical bias.
METHODS
The effect of optic nerve misrouting in persons with albinism and nystagmus (PWA, n = 14) on motion perception for MQ was compared with healthy controls (HC; n = 11) and with persons with nystagmus in the absence of optic nerve misrouting (PWN; n = 12). We varied the ratio of horizontal and vertical distances of MQ dots (aspect ratio [AR]) between 0.75 and 1.25 and compared the percentages of horizontal and vertical motion percepts as a function of AR between groups.
RESULTS
For HC, the probability of vertical motion perception increased as a sigmoid function with increasing AR exhibiting the expected vertical percept bias (mean, 58%; median, 54%; vertical motion percepts). PWA showed a surprisingly strong horizontal bias independent of the AR with a mean of 11% (median, 10%) vertical motion percepts. The PWN was in between PWA and HC, with a mean of 34% (median, 47%) vertical perception. Nystagmus alone is unlikely to explain this pattern of results because PWA and PWN had comparable fixation stabilities.
CONCLUSIONS
The strong horizontal bias observed in PWA and PWN might partly result from the horizontal nystagmus. The even stronger horizontal bias in PWA indicates that the intrahemispherical corepresentation of both visual hemifields may play an additional role. The altered perception of the MQ in PWA opens opportunities to (i) understand the interplay of stability and plasticity in altered visual pathway conditions and (ii) identify visual pathway abnormalities with a perception-based test using the MQ.
Topics: Humans; Albinism; Motion Perception; Nystagmus, Pathologic; Optic Chiasm; Optic Nerve
PubMed: 38015177
DOI: 10.1167/iovs.64.14.39 -
Journal of Personalized Medicine Nov 2023(1) Background: This study aims to highlight differences in the etiology and fitting of low vision aids in visually impaired children and adolescents in comparison to...
(1) Background: This study aims to highlight differences in the etiology and fitting of low vision aids in visually impaired children and adolescents in comparison to adults. (2) Methods: A retrospective data collection from visually impaired patients presenting to obtain assistive devices from 1 January 2016 to 30 April 2020 was conducted. A total of 502 patients were included. Inclusion criteria were a minimum age of 4 years and the chart notation of a best-corrected distance visual acuity in the patient record prior to the fitting of magnifying visual aids. (3) Results: Of the 502 patients, 147 (29.3%) were children under the age of 18 years. The most common cause of visual impairment in children was albinism, and in adults, it was age-related macular degeneration (AMD). Children showed better distance visual acuity, with a median of 0.88 logMAR (Logarithm of the Minimum Angle of Resolution) compared to 1.0 in adults ( = 0.001). Near visual acuity was also significantly better, with a median of 0.54 logMAR in children compared to 0.9 in adults ( < 0.001). Near and distance visual acuity were significantly improved by fitting magnifying visual aids ( < 0.001). After fitting, near visual acuity averaged 0.3 logMAR, and distance visual acuity, 0.7. The most commonly prescribed aids were optical vision aids, which 68.5% of the patients received; 43.8% received electronic aids. In children, optical aids were more frequently prescribed, and in adults, electronic and acoustic aids ( < 0.001). (4) Conclusion: Visually impaired patients can regain the ability to read and improve distance vision by using individually adapted and tested magnifying vision aids, often with optical aids alone. Differences between children and adults could be discovered in the etiology and severity of visual impairment, as well as in the provision type of low vision aids.
PubMed: 38003923
DOI: 10.3390/jpm13111608