Genetics of schizophrenia in the South African Xhosa
- Authors: Gulsuner, S , Stein, D J , Susser, E S , Sibeko, G , Pretorius, A , Walsh, T , Majara, L , Mndini, M M , Mqulwana, S G , Ntola, O A , Casadei, S , Zingela, Zukiswa , Nagdee, M , Ramesar, R S , King, M-C , McClellan, J M , Ngqengelele, L L , Korchina, V , van der Merwe, C , Malan, M , Fader, K M , Feng, M , Willoughby, E , Munzi, D , Andrews, H F , Gur, R C , Gibbs, R A
- Date: 2020
- Subjects: Schizophrenia -- Diagnosis -- Cross-cultural studies , Medical genetics , Xhosa (African people)
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/4217 , vital:44044 , https://doi.org/10.1126/science.aay8833
- Description: Africa, the ancestral home of all modern humans, is the most informative continent for understanding the human genome and its contribution to complex disease. To better understand the genetics of schizophrenia, we studied the illness in the Xhosa population of South Africa, recruiting 909 cases and 917 age-, gender-, and residence-matched controls. Individuals with schizophrenia were significantly more likely than controls to harbor private, severely damaging mutations in genes that are critical to synaptic function, including neural circuitry mediated by the neurotransmitters glutamine, γ-aminobutyric acid, and dopamine. Schizophrenia is genetically highly heterogeneous, involving severe ultrarare mutations in genes that are critical to synaptic plasticity. The depth of genetic variation in Africa revealed this relationship with a moderate sample size and informed our understanding of the genetics of schizophrenia worldwide.
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Potential latitudinal variation in orodigestive tract cancers in Africa
- Authors: Adeola, H A , Adefuye, A O , Jimoh, S A
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/5280 , vital:44428 , http://www.samj.org.za/index.php/samj/article/view/12259
- Description: Background. Previous studies have alluded to a causal relationship between pathological entities and geographical variations, but there is a paucity of studies from Africa discussing the effect of latitudinal variation on orodigestive cancers in this region. It seems plausible that the burden of orodigestive cancer would differ as a result of variations in diet, cultural habits, climate and environmental conditions down the length of Africa. Objectives. To analyse regional variations in prevalence, incidence and mortality data in the global cancer statistics database (GLOBOCAN 2012) curated by the World Health Organization and the International Agency for Research on Cancer. Basic descriptive statistical tools were used to depict regional variations in cancer morbidity and mortality. Methods. Data on 13 African countries between longitude 20⁰ and 30⁰ east and latitude 35⁰ north and 35⁰ south were examined for variation in age-standardised orodigestive cancer prevalence, incidence and mortality. Possible regional causes for orodigestive tract cancer development were investigated. Data on lip and oral cavity, oesophageal, gastric, colorectal, liver, gallbladder and pancreatic cancers in the 13 countries were compared. Results. Our empirical findings from this preliminary study support the notion that the incidence and prevalence of orodigestive cancers vary within Africa. This effect may be due to environmental, economic, political and possibly genetic factors. Conclusions. Considering the heterogeneity of the above factors across Africa, disbursement of funding for cancer research and therapy in Africa should be focused in terms of regional variations to make best use of the fiscal allocation by African governments, non-governmental organisations and international agencies.
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