Spinocerebellar ataxia type 1 (SCA1) is an autosomal dominant neurodegenerative disorder that primarily affects the cerebellum and brainstem. The genetic mutation is an expansion of CAG trinucleotide repeats within the coding region of the ataxin-1 gene, characterizing SCA1 as a polyglutamine expansion disease like Huntington’s. As with most polyglutamine expansion diseases, SCA1 follows the rules of genetic anticipation: the larger the expansion, the earlier and more rapid the symptoms. Unlike the majority of polyglutamine expansion diseases, the presence of histidine interruptions within the polyglutamine tract of ataxin-1 protein can prevent or mitigate disease.The present review aims to synthesize three decades of research on the ataxin-1 polyglutamine expansion mutation that causes SCA1. Data from genetic population studies and case studies is gathered along with data from manipulation studies in animal models. Specifically, we examine the molecular mechanisms that cause tract expansions and contractions, the molecular pathways that confer instability of tract length in gametic and somatic cells resulting in gametic and somatic mosaicism, the influence of maternal or paternal factors in inheritance of the expanded allele, and the effects of CAT/histidine interruptions to the ataxin-1 allele and protein product.Our review of existing data supports the following conclusions. First, polyCAG expansion of gametic alleles occur due to the failure of gap repair mechanisms for single or double strand breaks during the transition from an immature haploid spermatid to a mature haploid sperm cell. Equivalent failures were not detected in female gametic cells. Second, polyCAG expansion of somatic alleles occur due to hairpins formed on Okazaki fragments and slipped strand structures due to failures in mismatch repair and transcription-coupled nucleotide excision repair mechanisms. Third, CAT trinucleotide interruptions, which code for histidines in the translated protein, attenuate the formation of slipped strand structures which may protect the allele from the occurrence of large expansions. Many of the mechanisms of expansion identified in this review differ from those noted in Huntington’s disease indicating that gene -or sequence-specific factors may affect the behavior of the polyCAG/glutamine tract. Therefore, synthesis and review of research from the SCA1 field is valuable for future clinical and diagnostic work in the treatment and prevention of SCA1.

Nairobi’s urban slums are ill equipped to prevent spread of the novel coronavirus disease (COVID-19) due to high population density, multigenerational families in poorly ventilated informal housing, and poor sanitation. Physical distancing policies, curfews, and a citywide lockdown were implemented in March and April 2020 resulting in sharp decreases in movement across the city. However, most people cannot afford to stay home completely (e.g., leaving daily to fetch water). If still employed, they may need to travel longer distances for work, potentially exposing them COVID-19 or contributing to its spread. We conducted a household survey across five urban slums to describe factors associated with mobility in the previous 24 h. A total of 1695 adults were interviewed, 63% female. Of these, most reported neighborhood mobility within their informal settlement (54%), 19% stayed home completely, and 27% reported long-distance mobility outside their informal settlement, mainly for work. In adjusted multinomial regression models, women were 58% more likely than men to stay home (relative risk ratio (RRR): 1.58, 95% confidence interval (CI): 1.16, 2.14) and women were 60% less likely than men to report citywide mobility (RRR: 0.40; 95% CI 0.31, 0.52). Individuals in the wealthiest quintile, particularly younger women, were most likely to not leave home at all. Those who reported citywide travel were less likely to have lost employment (RRR: 0.49; 95% CI 0.38, 0.65) and were less likely to avoid public transportation (RRR: 0.30; 95% CI 0.23, 0.39). Employment and job hunting were the main reasons for traveling outside of the slum; less than 20% report other reasons. Our findings suggest that slum residents who retain their employment are traveling larger distances across Nairobi, using public transportation, and are more likely to be male; this travel may put them at higher risk of COVID-19 infection but is necessary to maintain income. Steps to protect workers from COVID-19 both in the workplace and while in transit (including masks, hand sanitizer stations, and reduced capacity on public transportation) are critical as economic insecurity in the city increases due to COVID-19 mitigation measures. Workers must be able to commute and maintain employment to not be driven further into poverty. Additionally, to protect the majority of individuals who are only travelling locally within their settlement, mitigation measures such as making masks and handwashing stations accessible within informal settlements must also be implemented, with special attention to the burden placed on women.

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Background Survey data that categorizes gender identity in binary terms and conflates sex and gender limits knowledge around the experience of gender minority populations, whose gender identity or expression does not align with the sex they were assigned at birth. In this review, we outline the existing survey research on the experience of a gender minority demographic for whom there is particularly limited data: adolescents and youth in low and middle-income countries (LMICs). Methods This paper is a scoping review of peer-reviewed articles, published in English, that use survey data to examine the experience of gender minority adolescents and youth in LMICs. We conducted a search on two major databases using key terms related to gender identity, adolescence and youth, and country and region. This search yielded 385 articles. Following a team-conducted review, we retained 33 articles for the final analysis. Results Our review shows that surveys with adolescents and youth in LMICs are increasingly including questions and taking sampling approaches that allow gender minority populations to be visible in survey data. Surveys that do so are largely focused in upper middle-income countries (n = 24), rather than lower middle-income or low-income countries, with South East Asia a notable sub-region of focus (n = 15). Sexual health, mental health, and violence are key topics of interest. Most of the surveys rely on some form of network-driven sampling focused on sexual and/or gender minorities (n = 22). The studies vary in how they ask about gender identity, both in terms of question formulation and the answer categories that are offered, as well as the extent to which they describe the questions in the article text. Conclusions This review reveals a growing body of work that provides important insights into the experiences of gender minority adolescents and youth in LMICs. More studies could integrate these approaches, but it must be done in a way that is thoughtful about cultural and political context. Given the relatively nascent nature of such research, we encourage scholars to continue providing details on methodology, including around participant recruitment and the development of gender identity questions. This information would be valuable for researchers seeking to better include gender minorities and their experiences in survey research, but who might be daunted methodologically.

L'Atlas des Adolescents pour l'Action (A3) est une suite d'outils qui résume la vie et les besoins des adolescents du monde entier afin de promouvoir une prise de décision fondée sur des données probantes. Grâce à des données accessibles et faciles à saisir en un seul clic, l'A3 comble le fossé entre les décideurs et les données factuelles afin d'éclairer les politiques et les programmes. La liste de contrôle des politiques A3, créée par le GIRL Center du Population Council, présente une liste de politiques nationales pertinentes pour la vie des adolescents dans 9 domaines thématiques, et indique si les pays ont adopté chaque politique. La liste de contrôle présente un aperçu des engagements pris pour atteindre le bien-être des adolescents par le biais de politiques axées sur les adolescents. En juillet 2022, la liste de contrôle des politiques comprend 56 politiques, qui ont été suivies pour 113 pays à revenu faible ou intermédiaire (PRFM). Cette liste de politiques n'est pas exhaustive, et des politiques supplémentaires seront ajoutées à la liste de contrôle chaque année. Ce document présente la méthodologie utilisée pour élaborer la liste de contrôle de la politique A3.