Trefor Jenkins

Clinical and molecular characterization of lipoid proteinosis in Namaqualand, South Africa.

Backgroundu2002 Lipoid proteinosis (LiP) is a rare autosomal recessive disorder characterized by a hoarse voice, warty skin infiltration and scarring. Mutations within the extracellular matrix protein 1 (ECM1) gene cause LiP. Since the early 1970s it has been recognized that South Africa has one of the largest groups of LiP patients worldwide, suggesting a probable founder effect. As LiP patients present with considerable clinical variability, this group of patients offers a unique opportunity for genotype–phenotype correlation.

DNA Polymorphism and Selection at the Melanocortin-1 Receptor Gene in Normally Pigmented Southern African Individuals

Abstract: Skin pigmentation is a polygenic multifactorial trait determined by the cumulative effects of multiple genetic variants and environmental factors. Melanocortin‐1 receptor (MC1R) is one of the genes involved in pigmentation, and has been implicated in the red hair and pale skin phenotype in human Caucasoid individuals. The present study was undertaken to identify variation at the MC1R locus in normally pigmented individuals in two African populations, sub‐Saharan Negroids (22 unrelated individuals) and the San (17 unrelated individuals). The study showed considerable MC1R gene sequence variation with the detection of eight synonymous and three nonsynonymous mutations. This is the first report of nonsynonymous mutations in African individuals in the MC1R gene: L99I was found in a single San individual, S47I was detected in a single Negroid individual, and F196L was detected in five Negroid individuals (5/44; 0.11). The functional significance of these mutations is not known. Three of the eight synonymous mutations found, L106L (CTG → CTA), F300F (TTC → TTT), and T314T (ACA → ACG) (also known as A942G), have been reported previously. T314T was the only variant that showed a significant difference between the Negroid and San populations (0.477 and 0.059, respectively; P= 1.6× 10−5). Its low frequency in the San may be the result of random genetic drift in a population of small size, or selection. Several tests of neutrality of the MC1R coding region in these and other African populations were significant, suggesting that purifying selection (functional constraint) had occurred at this gene locus in Africans. This demonstrates that although some nonsynonymous MC1R mutations are tolerated in individuals with dark skin, this gene has likely played a significant role in the maintenance of dark pigmentation in Africans and normal pigment variation in non‐African populations.

The Steve Biko affair

Steve Biko, a leader of the Black Consciousness movement in South Africa, died in 1977 while being detained by security police. The inquest into his death revealed gross inadequacies in the treatment he received from the two doctors legally responsible for his medical care. These doctors, Ivor Lang and Benjamin Tucker, were called in to examine Biko after he had sustained head injuries during interrogation by the security police. Over the five days in which they attended Biko, Lang and Tucker failed to take his condition seriously. The doctors failed to examine Biko under proper conditions despite clear signs of possible brain damage; they failed to take a history, they failed to do simple tests of Biko’s mental state, and allowed the police to be present during their examination and to influence their diagnosis and management. (The police had variously suggested that Biko had suffered a stroke or that he was shamming.) Lang then wrote a false medical certificate in which he claimed to have found no evidence of abnormality or pathology. He failed to note the injuries to Biko’s face and chest, his ataxic gait, and his slurred speech—all of which had been evident from the beginning. With subsequent deterioration in Biko’s condition, further examinations (including those performed by an independent physician in consultation with a neurosurgeon) revealed a left-sided positive Babinski sign, left-sided weakness, urinary incontinence, and blood in the cerebrospinal fluid, in addition to the earlier signs of brain damage. Nevertheless Lang then wrote in his patient’s notes:

Genetics, race and medicine : human genetics

The ‘race’ concept has been entrenched in European culture and literature only since long-distance ocean travel began in the mid-15th Century. Linnaeus, in 1758 classified Homo supiens into four subspecies or races; nearly 20 years later Blumenbach made it five races and introduced a ‘hierarchy of worth’ with Europeans at the top and Africans at the bottom. Throughout the 19th century and the first half of the 20th century, western European and American physical anthropologists were obsessed with race, entrenching a scientific racism shaken off only after the excesses of Nazi anthropology were exposed. With the rise of genetics and the demonstration of the ubiquity of genetic polymorphisms in humans, it became possible to study evolutionary processes in a quantitative way. The completion of the Human Genome Project in 2001 has stimulated scientists to study the genetic variation of humans at a level previously unimagined. Such studies confirm the existence of the major human ‘races’ and will facilitate re...The ‘race’ concept has been entrenched in European culture and literature only since long-distance ocean travel began in the mid-15th Century. Linnaeus, in 1758 classified Homo supiens into four subspecies or races; nearly 20 years later Blumenbach made it five races and introduced a ‘hierarchy of worth’ with Europeans at the top and Africans at the bottom. Throughout the 19th century and the first half of the 20th century, western European and American physical anthropologists were obsessed with race, entrenching a scientific racism shaken off only after the excesses of Nazi anthropology were exposed. With the rise of genetics and the demonstration of the ubiquity of genetic polymorphisms in humans, it became possible to study evolutionary processes in a quantitative way. The completion of the Human Genome Project in 2001 has stimulated scientists to study the genetic variation of humans at a level previously unimagined. Such studies confirm the existence of the major human ‘races’ and will facilitate research into the role of natural selection in human evolution, including race formation, as well into the causation of complex diseases, including hypertension, diabetes, the psychoses, asthma, and many others.