South African White Population Research Articles

Evaluation of the Suchey–Brooks age estimation method in a white South African population

Several studies have indicated that the time of onset of specific age-related changes throughout the human skeleton differs between populations. In this study the well-known Suchey–Brooks pubic symphyseal age estimation method was investigated to assess its performance in a white South African population. A total of 184 well-preserved os coxae were subjected to blind phase analysis, using the Suchey–Brooks descriptions and pubic symphyseal casts. The method performed well in a white South African population with statistically significant moderate positive correlations and relatively low biases in both males and females. However, due to the underperformance of the method in older individuals, new age ranges for phases IV through VI were created that are specific to the South African white population. This study indicated that Suchey–Brooks method can be used in a white South African population using the age ranges for phases I through III provided by Brooks and Suchey (1990), and the population specific age ranges for phase IV and V provided in this study.

Investigating SAPAP3 variants in the etiology of obsessive-compulsive disorder and trichotillomania in the South African white population

Background Obsessive-compulsive disorder (OCD) is a debilitating psychiatric disorder characterized by repeated obsessions and compulsions. Trichotillomania (TTM), a psychiatric disorder characterized by repetitive hairpulling, is presently classified as an impulse control disorder, but has also been viewed as an obsessive-compulsive spectrum disorder. Both conditions are complex disorders, with evidence from family and twin studies indicating that their etiology includes a genetic component. Results from a recent knockout animal model suggest that SAP90/PSD95-associated protein 3 (SAPAP3) may be involved in the pathophysiology of both disorders. Methods Seven polymorphic variants distributed across the gene encoding SAPAP3 were genotyped in South African white OCD (n = 172), TTM (n = 45), and control (n = 153) subjects. Single-locus and haplotype analyses were conducted to determine association between genetic variants and subjects with OCD, TTM, and controls. Results Although single-locus analysis revealed a significant association between rs11583978 in SAPAP3 and TTM, this association was nonsignificant after correction for multiple testing. In the OCD group, a significant association was observed between earlier age at onset and the A-T-A-T (rs11583978-rs7541937-rs6662980-rs4652867) haplotype compared with the C-G-G-G haplotype. Conclusions This study generated preliminary evidence to link SAPAP3 variants to the development of earlier onset OCD. Future studies should concentrate on locating the susceptibility variant(s) by focusing on functional polymorphisms within SAPAP3.

Sex determination from the talus of South african whites by discriminant function analysis.

The field of forensic anthropology involves the building of an antemortem profile of an individual from skeletal remains. This includes sex and race determination and age and stature estimation. Since most bones that are conventionally used for sex determination are often recovered either in a fragmented or incomplete state, it has become necessary to use denser bones that are often recovered intact, eg, the patella, calcaneus, and talus. Thus the aim of this study is to assess the sex-determining ability of each of the measurements of the talus and derive discriminant function equations for sex determination in the South African white population. Sixty male and 60 female tali of South African whites obtained from the Raymond A. Dart Collection of Human Skeletons were used. Nine measurements were taken on each talus. Descriptive statistics and discriminant function analysis were performed on the acquired data. The basic statistics showed that all measurements were sexually dimorphic. Univariate, stepwise, and direct discriminant function equations were generated for use in sex determination. The level of average accuracy of sex classification was 80% to 82% for the univariate method, 85% to 88% for the stepwise method, and 81% to 86% for the direct method. It is concluded that the talus of South African whites is useful for sex determination.

Discriminant Function Sexing of the Calcaneus of the South African Whites

The skull and some postcranial elements, such as the humerus, femur, and tibia, have been used in their intact states for sex determination in forensic and archaeological cases. But, in practice, these bones are often recovered in fragmented states, which render them unsuitable for use in sex determination. The calcaneus is a compact bone that is able to withstand high tensile forces. Some of its parameters have been used for sex determination in American whites and blacks (1) and Italians (2). This bone has not been used for sex determination in the South African white population. Therefore, the aim of this study was to assess the degree of sexual dimorphism of the calcaneus of the South African white population sample, derive discriminant function score equations for use in sex determination, and determine the level of accuracy of its sex-determining ability. Nine parameters were measured on each pair of 53 male and 60 female calcanei of known South African white skeletons, obtained by a random sampling technique from the Raymond A. Dart Collection of Human Skeletons, School of Anatomical Sciences, University of the Witwatersrand, Johannesburg. Basic statistic and discriminant function analysis was performed on the acquired data. The basic statistics showed that all measured parameters were sexually dimorphic. Discriminant function score equations were generated for use in sex determination. The average accuracy of sex classification ranged from 73 to 86% for the univariate method, 81 to 91% for the stepwise method, and 82 to 92% for the direct method. It is concluded that the calcaneus is useful for sex determination in the South African white population.

Population genetic data on five STR loci, vWA, TH01, TPOX, F13A01 and CSF1PO, in South African blacks and South African whites

Allele frequencies for five STR loci, vWA, TH01, TPOX, F13A01 and CSF1PO, were investigated in South African black and South African white populations. The population data did not deviate from the Hardy-Weinberg equilibrium in either population

The molecular basis of cystic fibrosis in South Africa.

The spectrum of CFTR mutations in three South African populations is presented. To date. a total of 192 white patients (384 chromosomes) with confirmed CF have been tested. deltaF508 accounts for 76% of the CF chromosomes in this group, with 3272-26A-->G, 394delTT and G542X occurring at the following frequencies: 4, 3.6 and 1.3%, respectively. A further 11 mutations account for 6% of CF chromosomes. A total of 91% of the CF-causing mutations can now be detected in the South African white population. Haplotype analysis suggests a founder effect in South Africans of European origin for the two common CFTR mutations, 3272-26A-->G and 394delTT. The diagnosis of CF has been confirmed in 14 coloured and 12 black CF patients. In the coloured population, both the deltaF508 and 3120 + 1G-->A mutations occur at appreciable frequencies of 43 and 29%, respectively. In the black population, the most common CF-causing mutation, the 3120 + 1G-->A mutation, occurs at an estimated frequency of 46%. Four other mutations have been detected, resulting in the identification of a total of 62.5% of mutations in this population.

Sex determination from the femur and tibia in South African whites

With the current high incidence of violent crimes in South Africa, it has become very important to be able to determine the sex of individuals from their skeletal remains. The aim of this study is to provide standards usable for this purpose, to be used on the contemporary South African white population. Very little skeletal data is available for this group. Osteometric information was obtained from 56 male and 50 female individuals from cadaver collections. Six femoral and seven tibial measurements were taken, and subjected to SPSS discriminant function analysis. The distal breadths from both the femur and tibia provided the best discrimination. Formulae were developed for a number of combinations of measurements, which can be used to determine the sex on fragmentary remains. Average accuracies ranged from 86% to 91%, with female accuracies slightly higher than those of the males. The results of this study compares well with others, e.g., those from American whites.

Polyps and colorectal cancer in South African Blacks.

This study reflects the fact that cancer of the large bowel is uncommon in South African Blacks, and that colorectal polyps do not appear to constitute a precursor to most colorectal cancers. Furthermore, it is shown that dietary factors associated with this cancer in Western populations are not evident in the Black population. In the South African White population, however, the disease behaves in a similar way to that observed in Western countries. Other definitive differences found were the absence of multiple synchronous cancers and diverticular disease in the Blacks with colorectal cancer. It is thus postulated that dietary factors are absent, or have not been present for a sufficient length of time to influence the development of polyps or polyp--cancer sequence in this population. It is also possible that the adenoma--carcinoma progression observed in Western countries may not be relevant to the development of all colorectal carcinomas in communities such as those reported here.