Phenotype and genetic analysis of data collected within the first year of NeuroDev

Genetic association studies have made significant contributions to our understanding of the etiology of neurodevelopmental disorders (NDDs). However, these studies rarely focused on the African continent. The NeuroDev Project aims to address this diversity gap through detailed phenotypic and genetic characterization of children with NDDs from Kenya and South Africa. We present results from NeuroDev's first year of data collection, including phenotype data from 206 cases and clinical genetic analyses of 99 parent-child trios. Most cases met criteria for global developmental delay/intellectual disability (GDD/ID, 80.3%). Approximately half of the children with GDD/ID also met criteria for autism. Analysis of exome-sequencing data identified a pathogenic or likely pathogenic variant in 13 (17%) of the 75 cases from South Africa and 9 (38%) of the 24 cases from Kenya. Data from the trio pilot are publicly available, and the NeuroDev Project will continue to develop resources for the global genetics community.

Burden of disease and barriers to comprehensive care for rheumatic heart disease in South Africa: an updated systematic review protocol

INTRODUCTION

Rheumatic heart disease (RHD) is responsible for a significant burden of cardiovascular morbidity and mortality, and remains the most common cause of acquired heart disease among children and young adults in low-income and middle-income countries. Additionally, the global COVID-19 pandemic has forced the emergency restructuring of many health systems, which has had a broad impact on health in general, including cardiovascular disease. Despite significant cost to the health system and estimates from 2015 indicating both high incidence and prevalence of RHD in South Africa, no cohesive national strategy exists. An updated review of national burden of disease estimates, as well as literature on barriers to care for patients with RHD, will provide crucial information to assist in the development of a national RHD programme.

METHODS AND ANALYSIS

Using predefined search terms that capture relevant disease processes from Group A Streptococcal (GAS) infection through to the sequelae of RHD, a search of PubMed, Scopus, ISI Web of Science, Sabinet African Journals, SA Heart and Current and Completed Research databases will be performed. All eligible studies on RHD, acute rheumatic fever and GAS infection published from April 2014 to December 2022 will be included. Vital registration data for the same period from Statistics South Africa will also be collected. A standardised data extraction form will be used to capture results for both quantitative and qualitative analyses. All studies included in burden of disease estimates will undergo quality assessment using standardised tools. Updated estimates on mortality and morbidity as well as a synthesis of work on primary, secondary and tertiary prevention of RHD will be reported.

ETHICS AND DISSEMINATION

No ethics clearance is required for this study. Findings will be disseminated in a peer-reviewed journal and submitted to national stakeholders in RHD.

PROSPERO REGISTRATION NUMBER

CRD42023392782.

Heterozygous variants in MYH10 associated with neurodevelopmental disorders and congenital anomalies with evidence for primary cilia-dependent defects in Hedgehog signaling

PURPOSE

Nonmuscle myosin II complexes are master regulators of actin dynamics that play essential roles during embryogenesis with vertebrates possessing 3 nonmuscle myosin II heavy chain genes, MYH9, MYH10, and MYH14. As opposed to MYH9 and MYH14, no recognizable disorder has been associated with MYH10. We sought to define the clinical characteristics and molecular mechanism of a novel autosomal dominant disorder related to MYH10.

METHODS

An international collaboration identified the patient cohort. CAS9-mediated knockout cell models were used to explore the mechanism of disease pathogenesis.

RESULTS

We identified a cohort of 16 individuals with heterozygous MYH10 variants presenting with a broad spectrum of neurodevelopmental disorders and variable congenital anomalies that affect most organ systems and were recapitulated in animal models of altered MYH10 activity. Variants were typically de novo missense changes with clustering observed in the motor domain. MYH10 knockout cells showed defects in primary ciliogenesis and reduced ciliary length with impaired Hedgehog signaling. MYH10 variant overexpression produced a dominant-negative effect on ciliary length.

CONCLUSION

These data presented a novel genetic cause of isolated and syndromic neurodevelopmental disorders related to heterozygous variants in the MYH10 gene with implications for disrupted primary cilia length control and altered Hedgehog signaling in disease pathogenesis.

The NeuroDev Study: Phenotypic and Genetic Characterization of Neurodevelopmental Disorders in Kenya and South Africa

The NeuroDev study will deeply phenotype cognition, behavior, dysmorphias, and neuromedical traits on an expected cohort of 5,600 Africans (1,800 child cases, 1,800 child controls, and 1,900 parents) and will collect whole blood for exome sequencing and biobanking.

Temporal trends of main reproductive characteristics in ten urban and rural regions of China: the China Kadoorie biobank study of 300 000 women

BACKGROUND

Chinese women's reproductive patterns have changed significantly over the past several decades. However, relatively little is known about the pace and characteristics of these changes either overall or by region and socioeconomic status.

METHODS

We examined the cross-sectional data from the China Kadoorie Biobank cohort study that recruited 300 000 women born between 1930 and 1974 (mean age: 51 years) from 10 socially diverse urban and rural regions of China. Temporal trends in several self-reported reproductive characteristics, and effect modification of these trends by area and education (as a surrogate for socioeconomic status), were examined.

RESULTS

The overall mean age at menarche was 15.4 (standard deviation 1.9) years, but decreased steadily over the 45 birth cohorts from 16.1 to 14.3 years, except for an anomalous increase of ∼1 year for women exposed to the 1958-61 famine in early adolescence. Similarly large changes were seen for other characteristics: mean parity fell (urban: 4.9 to 1.1; rural: 5.9 to 1.4); mean age at first birth increased (urban: 19.0 to 25.9 years; rural: 18.3 to 23.8 years); and birth spacing increased after 1980 to over 5 years. Breastfeeding declined after 1950 in urban and, after 1980, in rural women; and 68% of urban and 48% of rural women experienced a terminated pregnancy. Mean age at menopause increased from 47.9 to 49.3 years.

CONCLUSIONS

There have been striking changes in reproductive factors over time and between areas among these Chinese women. Their effects on major chronic diseases should be investigated.