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Background: Oculocutaneous albinism (OCA) is the most common inherited disorder in Southern African blacks and several types have been described. Molecular techniques, where available, can be used to confirm a clinical diagnosis and the type of OCA, if necessary, and for prenatal diagnosis., Objectives: To investigate and classify the different types of albinism commonly found and to determine the clinical implications for each type., Design: A descriptive survey., Setting: Gauteng province, South Africa, and Lesotho., Subjects: Three groups of subjects with OCA (96 from a genetics clinic, 62 from a dermatology clinic, and 31 from community surveys) from the black African population participated., Main Outcome Measures: Subjects underwent clinical and/or dermatological examinations and were then classified according to type of OCA., Results: Four forms of OCA were identified: most (82%) subjects had OCA2 (a tyrosinase- positive type) with three sub-types: those without large freckles (ephelides) on exposed areas (named OCA 2a in this study), those with such freckles (named OCA 2b), and those with brown albinism (BOCA); the remainder had red/rufous albinism, ROCA (OCA 3). The four forms could be distinguished from each other clinically without using molecular genetic testing., Conclusion: The most common types of albinism found in the black population of Southern Africa are OCA2 and OCA3. Given the high prevalence of the disorder, together with the high risk of skin cancer, and the recent persecution of affected individuals in certain East African countries, these findings and their clinical implications have significance in terms of both education and awareness for health professionals and lay people caring for those with albinism.

Background: The aim of this study was to document the nature, prevalence, and distribution of pigmented skin lesions in tyrosinase-positive oculocutaneous albinism (ty-pos OCA), the most common recessive disorder in South Africa (overall prevalence, 1 in 3900)., Methods: Sixty-one black subjects with ty-pos OCA (mean age, 23 years) and 65 normally pigmented black control subjects (mean age, 29 years) were studied., Results: Pigmented skin lesions not directly related to sun exposure included nevi and pigmented macules on the palms and soles. Melanocytic nevi, mostly on the trunk, were present in 82% of subjects with ty-pos OCA and in 71% of controls. The mean numbers were, however, greater in the ty-pos OCA subjects than in the controls (12 and 7, respectively), being closer to those reported in whites. Palmoplantar pigmentation was present in 75% of the control subjects, but in none of those with ty-pos OCA. The most striking sun-related lesions were dendritic freckles, which were present in 43% of ty-pos OCA subjects, and were characterized by an irregular branched shape, light to dark brown color, and large size (0.5-3.0 cm). Clinically, they resembled solar lentigines, but histologically the rete ridges were often flattened and there was no increase in the number of melanocytes. Solar keratoses occurred less frequently in ty-pos OCA subjects with dendritic freckles (50% vs. 73%), which confirmed the sun-protective role of the increased ability to form pigment., Conclusions: There were two major conclusions. Firstly pigmented nevi occur much more commonly in ty-pos OCA subjects than was previously thought, being similar in number to those found in white subjects. Secondly, dendritic freckles appear to represent a unique clinical and histologic entity found only on sun-exposed areas in ty-pos OCA subjects.

Red or rufous albinism is a rare type of oculocutaneous albinism described, but not as yet fully investigated, in Africa and New Guinea. Twelve rufous albino subjects from 10 families participated in this preliminary study. The prevalence of rufous albinism was found to be approximately one in 8,580 among school children in the negroid population. The combination of the unusual red skin colour, ginger to reddish hair colour, low susceptibility to sun damage, and minimal visual problems, in affected individuals, suggested that they form a group which is distinct from the brown and other types of albinism. The mode of inheritance was found to be recessive. Tyrosinase assays showed that rufous albinos are tyrosinase positive and on electron microscopy studies normal melanosomes and melanocytes were observed in hair bulbs and skin. Visual evoked potential testing did not show the gross decussation abnormalities of the optic pathway detected in other types of albinism. Rufous albinism might be at one end of the spectrum of types of oculocutaneous albinism and, because affected people have such mild symptoms, their inclusion in this group might be debatable.

The effects on iron absorption of nuts, an important source of dietary protein in many developing countries, were measured in 137 Indian women. When the absorption from bread and nut meals (walnuts, almonds, peanuts, and hazelnuts) was compared with that from bread meals, the overall geometric mean absorption from the nut meals (1.8%) was significantly less than from the bread meals alone (6.6%, t = 9.8, p less than 0.0005). In contrast, coconut did not reduce absorption significantly. All the nuts tested contained significant amounts of two known inhibitors of Fe absorption (phytates and polyphenols) but the amounts in coconut were significantly less than in the other nuts. Fifty milligrams ascorbic acid overcame the inhibitory effects of two nuts that were tested (Brazil nuts and peanuts). This is different from that found previously for soy protein, another potent inhibitor of Fe absorption.