[Correlation between refraction and axial length in Albinos]. / Corrélation entre la réfraction et la longueur axiale du sujet Albinos.

PURPOSE: To investigate the relationship between refraction and ocular axial length in albinos. PATIENTS AND METHODS: A cross-sectional, analytical study was carried out from June to November 2021 at the Central Hospital of Yaounde (Cameroon), which included consenting albino subjects aged over 15years. All subjects underwent visual acuity testing, axial length measurements and objective refraction under cycloplegia. RESULTS: We included 51 albino subjects. The mean age was 26.06±9.47years, and the sex ratio was 0.5. Type 2 oculocutaneous albinism (OCA2) was predominant, representing 82.4% of cases. The mean uncorrected visual acuity was 0.93±0.25 logMAR, and the most common ametropia was myopic astigmatism (52.9%). The mean axial length was 24.65±2.54mm with extremes of 21.54 and 30.33mm. Eyes with myopia and myopic astigmatism had significantly longer axial lengths than those with hyperopic and mixed astigmatism. A strong, significant negative correlation (r=-0.93; P˂0.001) between the spherical component of the refraction and axial length was found. CONCLUSION: The spherical component of the refraction decreases significantly with increasing axial length in albinos.

The experience of albinism in France: a qualitative study on dyads of parents and their adult child with albinism.

BACKGROUND: To date, almost no research on the psychosocial implications of albinism has been conducted in France and an exploration of albinism-related experiences could be beneficial, in order to better understand this condition. The aim of this study was to examine how French people with albinism and their parents live with and adapt to this condition in all the areas of their lives. METHODS: Semi-structured phone interviews were conducted with 9 parent-child dyads, each participating separately. Participants were recruited by convenience sampling, thanks to the combined efforts of a patient association (Genespoir) and professionals from the partner medical referral centers involved in the project. Dyads in which the individual with albinism had any comorbidity were excluded. The interviews were then transcribed and subjected to in-depth thematic analysis. Two codebooks were constructed in a mirrored process: one for people with albinism; the other for their parents. They were finally merged at the end of the coding step. RESULTS: Four main categories were identified: personal perceptions and social representations of albinism, difficulties and obstacles encountered by people with albinism, resources and facilitators, and the importance of parent-child functioning. The results indicated that experiences of stigmatization during childhood and adolescence are common and that people with albinism face challenges in adapting to certain obstacles related to their visual impairments (VI) (e.g., inability to drive a car; eye strain...). Parents emerged as one, if not as the main, source of support for people with albinism throughout their development. Although external support systems exist to assist them in various aspects of their lives, some of them primarily rely on their own personal resources to cope. CONCLUSIONS: This research highlights the importance of a systemic and transdisciplinary approach to make sure families receive the support that best meets their needs.

Molecular diagnostic challenges for non-retinal developmental eye disorders in the United Kingdom.

Overall, approximately one-quarter of patients with genetic eye diseases will receive a molecular diagnosis. Patients with developmental eye disorders face a number of diagnostic challenges including phenotypic heterogeneity with significant asymmetry, coexisting ocular and systemic disease, limited understanding of human eye development and the associated genetic repertoire, and lack of access to next generation sequencing as regarded not to impact on patient outcomes/management with cost implications. Herein, we report our real world experience from a pediatric ocular genetics service over a 12 month period with 72 consecutive patients from 62 families, and that from a cohort of 322 patients undergoing whole genome sequencing (WGS) through the Genomics England 100,000 Genomes Project; encompassing microphthalmia, anophthalmia, ocular coloboma (MAC), anterior segment dysgenesis anomalies (ASDA), primary congenital glaucoma, congenital cataract, infantile nystagmus, and albinism. Overall molecular diagnostic rates reached 24.9% for those recruited to the 100,000 Genomes Project (73/293 families were solved), but up to 33.9% in the clinic setting (20/59 families). WGS was able to improve genetic diagnosis for MAC patients (15.7%), but not for ASDA (15.0%) and congenital cataracts (44.7%). Increased sample sizes and accurate human phenotype ontology (HPO) terms are required to improve diagnostic accuracy. The significant mixed complex ocular phenotypes distort these rates and lead to missed variants if the correct gene panel is not applied. Increased molecular diagnoses will help to explain the genotype-phenotype relationships of these developmental eye disorders. In turn, this will lead to improved integrated care pathways, understanding of disease, and future therapeutic development.

Comorbidity of sickle cell trait and albinism: a cross-sectional survey in the Democratic Republic of the Congo.

INTRODUCTION: Sickle Cell Disease (SCD) and albinism are both recessive hereditary diseases in human kind with a high prevalence in sub-Saharan Africa. This study aimed to determinate the prevalence of sickle cell trait in people living with albinism (PLA). METHODS: a cross-sectional descriptive survey was conducted in PLA attending the "Hôpital du Cinquantenaire de Kisangani". In total, by non-probabilistic convenience sampling, 82 albinos and 139 non-albinos and without any antecedents of albinism in their family were included, selected from students in the Faculty of Medicine and Pharmacy at the University of Kisangani. Blood samples were collected on "dried blood spot" and analyzed by mass spectrometry at CHU of Liège. Data were entered into an Excel file and analysed on SPSS 20.0 (Chicago, IL). RESULTS: forty-six of the 82 albinos (56.1%) were female and 43.9% male with a sex ratio of 1.28. Among albinos, 18.3% had hemoglobin AS (HbAS) and 81.7% hemoglobin AA (HbAA) compared to 18% of subjects with hemoglobin AS and 82% hemoglobin AA in the control group. The difference was not statistically significant (Chi-square=0.003, ddl=1, p=0.9544). CONCLUSION: this study highlighted that the prevalence of the sickle cell trait is high among people living with albinism, but does not differ from that observed in non-albinos in the Democratic Republic of the Congo. It is therefore important to raise awareness among this category of people about sickle cell disease and the importance of its premarital screening.

Patterns of skin cancer and treatment outcomes for patients with albinism at Kisangani Clinic, Democratic Republic of Congo.

BACKGROUND: People with albinism (PWA) are at increased risk of photodamage and skin cancer. In many parts of Africa, there is a significant lack of knowledge regarding albinism which can lead to societal stigma, discrimination, and persecution from an early age. In the Democratic Republic of Congo (DRC), there is limited clinical data on PWA and skin cancer. We aim to better understand sociodemographics, risk factors, clinical features, and outcomes of this population. METHODS: Patients with a diagnosis of albinism and skin cancer presenting to Kisangani Albino Clinic were enrolled. RESULTS: Of 205 PWA, 61 patients were diagnosed with skin cancer with a mean age of 26.5 years. Common occupations were student (45.6%) or unemployed (26.4%). Discrimination was experienced from close contacts (24.4%) and society (67.4%). A majority (88.5%) had never used sunscreen, only 4.9% used fully sun protective clothing, and 90.2% spent 4 or more hours in the sun daily. Skin cancers had a mean size of 3.8 cm and were most commonly located on the face (47.7%). Squamous cell carcinoma was the most common histopathological diagnosis. Most patients underwent excision, and 90.2% had clinical clearance of tumors at a mean follow-up of 5.7 months. CONCLUSION: People living with albinism in the DRC experience a high rate of nonmelanoma skin cancers at a young age and additionally face a number of psychosocial challenges. This study represents the first attempt to analyze a cohort of patients with albinism from the DRC and serves to increase awareness of this vulnerable population.

Dermatological and Epidemiological Profiles of Patients with Albinism in São Paulo, Brazil, between 2010 and 2017: A Cross-Sectional Study.

INTRODUCTION: Oculocutaneous albinism is an autosomal recessive disease caused by complete absence of or decrease in melanin biosynthesis in melanocytes. Due to the reduction or absence of melanin, albinos are highly susceptible to the harmful effects of ultraviolet radiation and are at greater risk of actinic damage and skin cancer. There are no epidemiological data on the incidence of albinism in Brazil. OBJECTIVE: To analyze the clinical and epidemiological profile of patients with albinism treated by the Pró-Albino Program of the Dermatology Clinic of Santa Casa de Misericórdia from its beginning in 2010 until 2017. METHODS: In this cross-sectional study, the records of all consecutive albino patients admitted to the service in the study period were reviewed. Sociodemographic data, family history, and dermatological clinical data were collected. RESULTS: Between March 2010 and April 2017, 191 patients were admitted, of whom 109 were female (57.07%) and the age range was 0-92 years, with >30% under the age of 18 years. Consanguinity among the parents was confirmed by 26% of the patients. Unprotected sun exposure was reported by 109 (57.07%), and 138 (72.25%) had a history of sunburn. Of the 146 records with information, 38 had skin cancer (26%), with a mean age of 47.4 (p < 0.0001); the youngest patient diagnosed with a cutaneous tumor was 23 years old. The prevalence of actinic damage was high. There was information on solar elastosis and actinic keratosis in 148 medical records, of which 96 (64.8%) patients had elastosis and 75 (50.67%) keratoses. Elastosis, keratosis, and skin cancer were significantly associated with age, unprotected sun exposure, and sunburn (p < 0.05). Of the 37 (26% of the sample of 146) patients with a previous or current history of skin cancer, it was possible to identify the histological type in 29 (13 men and 16 women); of these, 18 (62%) were basal cell carcinomas (BCC), 15 (51%) were squamous cell carcinomas (SCC), and 2 (7%) were melanomas. Of these, 4 cases (14%) presented the 2 types of carcinoma (BCC and SCC), and the 2 that had a diagnosis of melanoma also had BCC. Some patients had multiple ulcerated tumors. The tumor site was preferentially in the head and neck (43%), trunk (37%) and limbs (20%). CONCLUSIONS: Albinos represent a risk group for skin cancer and other actinic lesions. These lesions were found to be prevalent in the albinos seen by the program and probably reflect the characteristics found in the Brazilian albino population. Access to health care, especially through multidisciplinary programs that enable the diagnosis and early treatment of these lesions, health education, and the use of photoprotective measures can reduce morbidity and mortality and improve the quality of life of patients with this rare genetic condition.

Albinism: epidemiology, genetics, cutaneous characterization, psychosocial factors.

Oculocutaneous albinism is an autosomal recessive disease caused by the complete absence or decrease of melanin biosynthesis in melanocytes. Due to the reduction or absence of melanin, albinos are highly susceptible to the harmful effects of ultraviolet radiation and are at increased risk of actinic damage and skin cancer. In Brazil, as in other parts of the world, albinism remains a little known disorder, both in relation to epidemiological data and to phenotypic and genotypic variation. In several regions of the country, individuals with albinism have no access to resources or specialized medical care, and are often neglected and deprived of social inclusion. Brazil is a tropical country, with a high incidence of solar radiation during the year nationwide. Consequently, actinic damage and skin cancer occur early and have a high incidence in this population, often leading to premature death. Skin monitoring of these patients and immediate therapeutic interventions have a positive impact in reducing the morbidity and mortality associated with this condition. Health education is important to inform albinos and their families, the general population, educators, medical professionals, and public agencies about the particularities of this genetic condition. The aim of this article is to present a review of the epidemiological, clinical, genetic, and psychosocial characteristics of albinism, with a focus in skin changes caused by this rare pigmentation disorder.

Albinism: epidemiology, genetics, cutaneous characterization, psychosocial factors

Abstract Oculocutaneous albinism is an autosomal recessive disease caused by the complete absence or decrease of melanin biosynthesis in melanocytes. Due to the reduction or absence of melanin, albinos are highly susceptible to the harmful effects of ultraviolet radiation and are at increased risk of actinic damage and skin cancer. In Brazil, as in other parts of the world, albinism remains a little known disorder, both in relation to epidemiological data and to phenotypic and genotypic variation. In several regions of the country, individuals with albinism have no access to resources or specialized medical care, and are often neglected and deprived of social inclusion. Brazil is a tropical country, with a high incidence of solar radiation during the year nationwide. Consequently, actinic damage and skin cancer occur early and have a high incidence in this population, often leading to premature death. Skin monitoring of these patients and immediate therapeutic interventions have a positive impact in reducing the morbidity and mortality associated with this condition. Health education is important to inform albinos and their families, the general population, educators, medical professionals, and public agencies about the particularities of this genetic condition. The aim of this article is to present a review of the epidemiological, clinical, genetic, and psychosocial characteristics of albinism, with a focus in skin changes caused by this rare pigmentation disorder.

Assessment of prison life of persons with disability in Ghana.

BACKGROUND: Persons with Disabilities (PWDs) are a unique group that are often overlooked in many developing countries due to systemic weaknesses, lack of political commitment and inadequate support from government and non-governmental agencies. The population of these individuals is however steadily on the increase and currently corresponds to 15 % of the world population. Although much data exist on lifestyle and conditions of prisoners with disabilities in the western world, scanty information is available in Africa. In Ghana, there is insufficient data on the occurrence and social characteristics of prisoners with disabilities. The purpose of this current study was therefore to identify the occurrence, types and causes of disabilities among prisoners serving sentences in Ghanaian prisons. METHODS: This study was a descriptive cross-sectional survey conducted in the Male and Female Regional Prisons in Kumasi, Sunyani and the Nsawam Medium Security Prison, from November to December 2011. PWDs were selected by prisons officers and interviewed using structured questionnaires on variables such as socio-demographic characteristics, causes of disabilities and accessibility to recreational facilities. Ethical approval was obtained from the security services and the Committee of Human Research Publications and Ethics (CHRPE) of the School of Medical Sciences, Kwame Nkrumah University of Science and Technology (KNUST). RESULTS: We screened 6114 records of prisoners of which 1852 (30.3 %) were from the Kumasi Central Prisons, 3483 (57 %) from the Nsawam Medium Security and 779 (12.8 %) from the Sunyani Central Prisons. A total of 99 PWDs were identified with the commonest disability being physical, followed by visual, hearing, speech, mental and albinism. Most of the disabilities were caused by trauma (68.8 %) followed by infection (16.7 %), and drug related mental disabilities (6.3 %). Fifty (50.5 %) out of the 99 PWDs were not provided with assistive devices although they admitted the need for such. CONCLUSION: The present study has demonstrated the occurrence and conditions of PWDs in Ghanaian prisons. Major stakeholders including government agencies and other organisations could develop policies that would improve the conditions and livelihood of prisoners with disabilities in Ghana.

[Leucoderma in children: Review of the literature]. / Leucodermies chez l'enfant : revue de la littérature.

BACKGROUND: Leucoderma is a frequent presenting complaint in children and it is sometimes difficult to make a definite diagnostic during the first consultation. The aim of this study is to analyse the diagnoses associated with leucoderma in children in order to propose a practical approach to their differential diagnosis. MATERIAL AND METHODS: We performed a review of the literature using the keywords "leucoderma children review", "leucoderma Ito" and "nevus depigmentosus" in the Medline database. All relevant articles were included. RESULTS: Four hundred and thirty-five articles were retrieved and 179 were analysed. A clinical approach was proposed in 6 articles and investigations in 15 articles. DISCUSSION: Causal diagnosis of leucoderma may frequently be made on clinical grounds by determining the age of onset and distribution of lesions. Nevertheless, some situations require investigation. The literature is limited regarding clinical approaches and examinations in leucoderma. Herein, we present a systematic clinical and laboratory approach to the differential diagnosis of these skin disorders.

Quantification and comparison of psychiatric distress in African patients with albinism and vitiligo: a 5-year prospective study.

BACKGROUND: Vitiligo and albinism are two disorders of pigmentation that make the affected African highly visible and strikingly different from their peers. Both pose considerable management challenges, attract significant stigma and profound impairment of quality of life. OBJECTIVE AND METHODS: To determine and compare psychiatric distress in vitiligo and albinism using the Hospital Anxiety and Depression Scale (HADS). Participants were 87 albinos and 102 vitiligo adult patients seen at an urban tertiary hospital in Nigeria between 2004 and 2009. RESULTS: Prevalence of psycho morbidity was 59% (60/102) in vitiligo compared with 26% (23/87) in the albinos. The mean anxiety score was estimated to be 2.55 points lower for albino patients (95% CI: 1.47 to 3.64), and the mean depression score 2.76 points lower (95% CI: 1.84 to 3.68), after adjustment for age, sex and marital status. However, significant differences were not observed when comparing the vitiligo patients with the subset of albino patients with skin cancer. Older patients had significantly higher anxiety and depression scores. Females had significantly higher anxiety scores (but not depression scores) compared to males. Genital involvement in vitiligo was significantly associated with anxiety but not depression. CONCLUSIONS: We found that the African with vitiligo suffers significantly higher psychiatric distress than the African albino on average. Clinical evaluation of these patients would be incomplete without assessment of their psycho morbidity. There is need for increased focus on cancer prevention strategies in the African albino.

Clinical, laboratory and molecular signs of immunodeficiency in patients with partial oculo-cutaneous albinism.

Hypopigmentation disorders that are associated with immunodeficiency feature both partial albinism of hair, skin and eyes together with leukocyte defects. These disorders include Chediak Higashi (CHS), Griscelli (GS), Hermansky-Pudlak (HPS) and MAPBP-interacting protein deficiency syndromes. These are heterogeneous autosomal recessive conditions in which the causal genes encode proteins with specific roles in the biogenesis, function and trafficking of secretory lysosomes. In certain specialized cells, these organelles serve as a storage compartment. Impaired secretion of specific effector proteins from that intracellular compartment affects biological activities. In particular, these intracellular granules are essential constituents of melanocytes, platelets, granulocytes, cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells. Thus, abnormalities affect pigmentation, primary hemostasis, blood cell counts and lymphocyte cytotoxic activity against microbial pathogens. Among eight genetically distinct types of HPS, only type 2 is characterized by immunodeficiency. Recently, a new subtype, HPS9, was defined in patients presenting with immunodeficiency and oculocutaneous albinism, associated with mutations in the pallidin-encoding gene, PLDN.Hypopigmentation together with recurrent childhood bacterial or viral infections suggests syndromic albinism. T and NK cell cytotoxicity are generally impaired in patients with these disorders. Specific clinical and biochemical phenotypes can allow differential diagnoses among these disorders before molecular testing. Ocular symptoms, including nystagmus, that are usually evident at birth, are common in patients with HPS2 or CHS. Albinism with short stature is unique to MAPBP-interacting protein (MAPBPIP) deficiency, while hemophagocytic lymphohistiocytosis (HLH) mainly suggests a diagnosis of CHS or GS type 2 (GS2). Neurological disease is a long-term complication of CHS, but is uncommon in other syndromic albinism. Chronic neutropenia is a feature of HPS2 and MAPBPIP-deficiency syndrome, whereas it is usually transient in CHS and GS2. In every patient, an accurate diagnosis is required for prompt and appropriate treatment, particularly in patients who develop HLH or in whom bone marrow transplant is required. This review describes the molecular and pathogenetic mechanisms of these diseases, focusing on clinical and biochemical aspects that allow early differential diagnosis.

Doenças hereditárias e defeitos congênitos diagnosticados em búfalos (Bubalus bubalis) no Brasil / Hereditary diseases and congenital defects diagnosed in water buffalo (Bubalus bubalis) in Brazil

A review on hereditary diseases and/or congenital defects diagnosed in water buffaloes in Brazil is performed. The epidemiological, clinical and pathological aspects of each disease or group of diseases are briefly described. Hereditary diseases include acantholytic mechanobullous dermatosis, arthrogryposis, myotonia, hydranencephaly, chondrodysplasia, and albinism. Congenital defects of unknown cause include megaesophagus, heart defects (patent ductus arteriosus), dermatosparaxia, and different defects of the reproductive system. The breeds most affected by genetic diseases are those from Asian Continent (Murrah and Jafarabadi), probably as a result of inbreeding in Brazilian herds due the prohibition of importation of breeding buffalo from that continent. The diagnosis of two hereditary diseases, arthrogryposis and myotonia, in Rio Grande do Sul (southern Brazil) and Pará (nothern Brazil) suggests that the undesirable genes are widespread in the buffalo population. The identification of these genes by molecular techniques associated with the buffalo breeding with correct sanitary, zootechnical, and reproductive control practices can decrease the negative effects of genetic diseases in the Brazilian buffalo herd.

É realizada uma revisão sobre as doenças hereditárias e/ou defeitos congênitos diagnosticados em búfalos no Brasil. São descritos brevemente os aspectos epidemiológicos, clínicos e patológicos de enfermidades hereditárias ou provavelmente hereditárias já observadas no Brasil, como dermatose mecanobolhosa, artrogripose, miotomia, hidranencefalia, condrodisplasia e albinismo; e dos defeitos congênitos que não tem uma causa ainda comprovada como megaesôfago, defeitos cardíacos (persistência do ducto arterioso), dermatosparaxia, defeitos no sistema reprodutivo e outros defeitos. Observou-se que as raças mais afetadas por enfermidades de natureza genética são as que têm origem no Continente Asiático (Murrah e Jafarabadi), provavelmente em consequência da consanguinidade existente nos rebanhos devido a proibição da importação de reprodutores, sêmen e embriões daquele continente. O diagnóstico de duas dessas doenças, artrogripose e miotomia hereditária no Rio Grande do Sul e no Pará, demonstra que os genes indesejáveis estão disseminados na população de búfalos no país e que a identificação desses genes por meio de técnicas moleculares associada à criação desta espécie com maior controle sanitário, reprodutivo e zootécnico pode minimizar os prejuízos decorrentes dessas enfermidades à bubalinocultura.

Anomalous colour in Neotropical mammals: a review with new records for Didelphis sp. (Didelphidae, Didelphimorphia) and Arctocephalus australis (Otariidae, Carnivora).

Anomalous colourations occur in many tropical vertebrates. However, they are considered rare in wild populations, with very few records for the majority of animal taxa. We report two new cases of anomalous colouration in mammals. Additionally, we compiled all published cases about anomalous pigmentation registered in Neotropical mammals, throughout a comprehensive review of peer reviewed articles between 1950 and 2010. Every record was classified as albinism, leucism, piebaldism or eventually as undetermined pigmentation. As results, we report the new record of a leucistic specimen of opossum (Didelphis sp.) in southern Brazil, as well as a specimen of South American fur seal (Arctocephalus australis) with piebaldism in Uruguay. We also found 31 scientific articles resulting in 23 records of albinism, 12 of leucism, 71 of piebaldism and 92 records classified as undetermined pigmentation. Anomalous colouration is apparently rare in small terrestrial mammals, but it is much more common in cetaceans and michrochiropterans. Out of these 198 records, 149 occurred in cetaceans and 30 in bats. The results related to cetaceans suggest that males and females with anomolous pigmentation are reproductively successful and as a consequence their frequencies are becoming higher in natural populations. In bats, this result can be related to the fact these animals orient themselves primarily through echolocation, and their refuges provide protection against light and predation. It is possible that anomalous colouration occurs more frequently in other Neotropical mammal orders, which were not formally reported. Therefore, we encourage researchers to publish these events in order to better understand this phenomenon that has a significant influence on animal survival.

Anomalous colour in Neotropical mammals: a review with new records for Didelphis sp. (Didelphidae, Didelphimorphia) and Arctocephalus australis (Otariidae, Carnivora) / Coloração anômala em mamíferos Neotropicais: uma revisão com novos registros para Didelphis sp. (Didelphidae, Didelphimorphia) e Arctocephalus australis (Otariidae, Carnivora)

Anomalous colourations occur in many tropical vertebrates. However, they are considered rare in wild populations, with very few records for the majority of animal taxa. We report two new cases of anomalous colouration in mammals. Additionally, we compiled all published cases about anomalous pigmentation registered in Neotropical mammals, throughout a comprehensive review of peer reviewed articles between 1950 and 2010. Every record was classified as albinism, leucism, piebaldism or eventually as undetermined pigmentation. As results, we report the new record of a leucistic specimen of opossum (Didelphis sp.) in southern Brazil, as well as a specimen of South American fur seal (Arctocephalus australis) with piebaldism in Uruguay. We also found 31 scientific articles resulting in 23 records of albinism, 12 of leucism, 71 of piebaldism and 92 records classified as undetermined pigmentation. Anomalous colouration is apparently rare in small terrestrial mammals, but it is much more common in cetaceans and michrochiropterans. Out of these 198 records, 149 occurred in cetaceans and 30 in bats. The results related to cetaceans suggest that males and females with anomolous pigmentation are reproductively successful and as a consequence their frequencies are becoming higher in natural populations. In bats, this result can be related to the fact these animals orient themselves primarily through echolocation, and their refuges provide protection against light and predation. It is possible that anomalous colouration occurs more frequently in other Neotropical mammal orders, which were not formally reported. Therefore, we encourage researchers to publish these events in order to better understand this phenomenon that has a significant influence on animal survival.

Colorações anômalas ocorrem em muitos vertebrados tropicais. Entretanto, estas são consideradas raras em populações selvagens, havendo poucos registros para a maioria dos táxons. Reportam-se, neste estudo, dois novos casos de coloração anômala em mamíferos. Além disso, por meio de uma extensa revisão bibliográfica, foram compilados os casos publicados sobre coloração anômala em mamíferos neotropicais entre 1950 e 2010. Cada registro foi classificado como albinismo, leucismo, piebaldismo ou, eventualmente, como coloração indeterminada. Como resultados, reportou-se o registro de um espécime leucístico de gambá (Didelphis sp.) no sul do Brasil e de um espécime de lobo-marinho sul-americano (Arctocephalus australis) com piebaldismo no norte do Uruguai. Também foram analisados 31 artigos científicos, resultando em 23 registros de albinismo, 12 de leucismo, 71 de piebaldismo e 92 registros classificados como de pigmentação indeterminada. A coloração anômala aparentemente é rara em pequenos mamíferos terrestres, mas é muito mais comum em cetáceos e microquirópteros. Dos 198 registros encontrados, 149 ocorreram em cetáceos e 30 em morcegos. No caso dos cetáceos, este resultado sugere que machos e fêmeas com este padrão anômalo de pigmentação são reprodutivamente exitosos e, consequentemente, sua frequência está aumentando nas populações naturais. Com relação aos morcegos, este fenômeno pode estar relacionado ao fato de estes animais orientarem-se primariamente por meio de ecolocalização e seus refúgios oferecerem proteção contra luz e predação. É possível que a coloração anômala ocorra mais frequentemente em outras ordens de mamíferos neotropicais, as quais não foram formalmente reportadas. Desta forma, mostra-se importante encorajar os pesquisadores a publicar estes eventos em vida selvagem para um melhor entendimento deste fenômeno, que tem influência significativa na sobrevivência destes organismos.

Molecular basis of albinism in India: evaluation of seven potential candidate genes and some new findings.

Albinism represents a group of genetic disorders with a broad spectrum of hypopigmentary phenotypes dependent on the genetic background of the patients. Oculocutaneous albinism (OCA) patients have little or no pigment in their eyes, skin and hair, whereas ocular albinism (OA) primarily presents the ocular symptoms, and the skin and hair color may vary from near normal to very fair. Mutations in genes directly or indirectly regulating melanin production are responsible for different forms of albinism with overlapping clinical features. In this study, 27 albinistic individuals from 24 families were screened for causal variants by a PCR-sequencing based approach. TYR, OCA2, TYRP1, SLC45A2, SLC24A5, TYRP2 and SILV were selected as candidate genes. We identified 5 TYR and 3 OCA2 mutations, majority in homozygous state, in 8 unrelated patients including a case of autosomal recessive ocular albinism (AROA). A homozygous 4-nucleotide novel insertion in SLC24A5 was detected in a person showing with extreme cutaneous hypopigmentation. A potential causal variant was identified in the TYRP2 gene in a single patient. Haplotype analyses in the patients carrying homozygous mutations in the classical OCA genes suggested founder effect. This is the first report of an Indian AROA patient harboring a mutation in OCA2. Our results also reveal for the first time that mutations in SLC24A5 could contribute to extreme hypopigmentation in humans.