Since the publication of the human genome sequence in 2003, the significance of the contribution of genetic variation to a myriad of human diseases has become apparent. The advancement of sequencing technologies has drastically increased their accessibility and decreased their cost, enabling the identification of not only large disease-causing genomic rearrangements but also a plethora of small insertions or deletions and single-nucleotide variants, the accumulation of which may be associated with everything from monogenic disease traits to the increased risk of disease development. Indeed, in the two decades that have passed since the start of the Human Genome Project, it has become clear that the genetic component of disease is highly complex, involving genomic variation, post-translational modifications, and a variety of regulatory elements. Consequently, human genetics research has become fundamental for the understanding of the human disease state and advancement of medical testing, diagnosis, and treatment.

In this Special Collection, we present the most highly cited and downloaded articles published in 2019 from the Wiley journals American Journal of Medical Genetics Parts A, B (Neuropsychiatric Genetics), and C (Seminars in Medical Genetics), Annals of Human Genetics, Birth Defects Research, Genetic Epidemiology, Human Mutation, and Molecular Genetics & Genomic Medicine. These articles will give you a cutting-edge overview of the most impactful research findings into the genetic components underlying many diseases, the development of novel diagnostic methods, and hypotheses that await testing. We hope you enjoy reading these insightful articles that represent a hopeful future for the many affected by genetic disease. Consider submitting your own research to these respected journals.