Albinism research in a Southern African setting: unique findings

Journal of Community Genetics (2025) 16:107–116 https://doi.org/10.1007/s12687-025-00786-3 REVIEW Albinism research in a Southern African setting: unique findings Jennifer G. R. Kromberg1 · Robyn A. Kerr1 Received: 16 April 2024 / Accepted: 9 March 2025 / Published online: 26 March 2025 © The Author(s) 2025 Abstract Research on oculocutaneous albinism (OCA) in the black African population has been ongoing for 52 years (1971–2023) in the Division of Human Genetics, University of the Witwatersrand, Johannesburg, South Africa. The aim of the present study was to review all the relevant published articles and focus on selected articles with unique findings. The results showed that unique findings were reported in psychosocial, cultural, epidemiological, clinical and molecular fields of study. The local prevalence of albinism was found to be 1 in 3900, higher than that reported in many other countries, although a worldwide review on prevalence showed that only 26/193 (13%) countries had published figures; the commonest types of OCA found were OCA2 and then OCA3; the high rate of skin cancer was documented; and the natural history of OCA described. Molecular studies showed that the 2.7 kb deletion mutation in the OCA2 gene is the common mutation in OCA2 locally, and further identified unique mutations in TYRP1 causing rufous albinism (OCA3) in this population. An early study found that after the birth of a child with OCA maternal-infant bonding was delayed, and only established some months later. Further research revealed that superstitions and myths surrounded the birth and the death of a person with OCA, and the belief that powerful medicines could be made from body parts, was very disturbing. Genetic causes of OCA were poorly understood by affected individuals, their relatives and communities, and genetic counselling is essential. In summary, over 30 studies were undertaken and published over a period of five decades, and many presented unique findings on this under-researched inherited condition. Keywords Albinism · South Africa · Clinical · Epidemiology · Psychosocial · Genetics Introduction Albinism is a well-recognised disorder which, although it occurs in about 1 in 5000 individuals in Africa (Hong et al. 2006), is a rare and under-researched condition in most parts of the world. Since the early 1900s it has been understood to be genetic with a recessive mode of inheritance (Davenport and Davenport 1910). It is caused by biallelic gene mutations, at a single gene locus, which result in a lack of melanin pigment production in the cell (Rooryck et al. 2009). There are two main types of albinism: oculocutaneous albinism (OCA) and ocular albinism (OA). In the first case Robyn A. Kerr 1 Division of Human Genetics, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand and National Health Laboratory Service, PO Box 1038, Johannesburg 2000, South Africa the affected individual has depigmentation of both eyes and skin, in the second case only the eyes lack pigment. OCA is far more common than OA, particularly in Africa, where very few cases of OA have been reported and there is a higher prevalence of OCA than on any other continent. This article will focus on OCA, and on Southern Africa where much of the African albinism research, which has resulted in several unique findings, has been undertaken (Kromberg and Manga 2018). In OCA, lack of melanin in the eye results in low vision, and lack of melanin in the skin results in a predisposition to skin cancer (squamous and basal cell). There are 7 types of OCA and these have been differentiated (Monteliu et al. 2014). Further, Manga (2018) has published a comprehensive discussion on the molecular and biochemical basis of OCA, which includes a detailed description of OCA 1–7. OCA type 1 (MIM: # 203100) results from variation at the TYR locus which leads to a lack of tyrosinase, an enzyme essential during melanin biosynthesis. This is the most severe form of albinism with complete lack of pigment in the 13 108 skin, hair and eyes; individuals have whitish skin and hair and light blue eyes. OCA type 2 (MIM: # 203200) results from variation at the OCA2 locus (previously referred to as the P locus), and individuals have a slightly milder phenotype with an accumulation of some red/yellow phaeomelanin as the individual ages, and hazel-coloured eyes. OCA type 3 (# 203290) is significantly less severe than types 1 and 2 and is referred to as rufous or red oculocutaneous albinism (ROCA), and in individuals of African descent the phenotype is one of a coppery brown skin, lighter than normally pigmented individuals but not ‘white’ as for OCA1 and OCA2 in this population. In OCA3 secondary changes in the retinas can be observed but the visual impairment is minimal. The other types of OCA are rare worldwide and have not been described in Africa. In the early 1970s a research project on albinism was initiated by a team (a medical doctor, medical social worker, and later, a nurse) working at the South African Institute for Medical Research (SAIMR, now the National Health Laboratory Service, NHLS) and University of the Witwatersrand, in the Division of Human Genetics, in Johannesburg, South Africa; this research continued for five decades. The project focussed on the epidemiology of albinism initially, since individuals with the condition were often observed but the prevalence was unknown. The study was expanded into the psychosocial field and later into the clinical, and molecular aspects of the condition, as the necessary expertise became available in the department. Research was supported by long-term funding from the South African Medical Research Council (for two sessions of five years each), and thereafter by various smaller research grants. The purpose of this review paper is to outline some of the unique findings resulting from the many studies on OCA performed over the last 52 years (1971–2023), in this setting. These findings produced unique insights into the albinism condition at the time they were undertaken, since they were focussed on albinism in Southern Africa (understudied in this setting, despite a relatively high prevalence). Some of the studies made a unique contribution to world knowledge, others were more specifically unique to Africa and /or Southern Africa. The article will not take a chronological approach (which might have shown how research methodologies and research expertise developed over the decades) to the presentation of the many research projects undertaken. Instead, it will cover the epidemiological and clinical research topics first, followed by the genetic and molecular topics and, lastly, the psychosocial and cultural studies. Finally, for the sake of completeness, the human rights issues that have arisen while this research has been undertaken, but have not yet been studied in detail, will be briefly discussed. 13 Journal of Community Genetics (2025) 16:107–116 Clin (...truncated)