| By Barbara Wexler, MPH, and Brigham Narins |
Newly published, The Gale Encyclopedia of Genetic Disorders, 5th edition, covers a wide range of topics, from diseases and conditions to therapies and treatments to social and ethical issues—all focusing on genetics and the human genome.
We’re at the dawn of a golden age of genetic and genomic science and medicine. Once the stuff of science fiction, sequencing the entire human genome is now a relatively routine, though nonetheless remarkable, procedure. Genetic research has opened a veritable treasure chest—and in some instances, a Pandora’s box—of new scientific and medical insights.
Genetics is the study of single genes and their effects on the body and mind. Genetics explains how and why certain traits, such as hair color and blood type, run in families. Genomics is the study of more than single genes. Genomics considers the functions and interactions of all the genes in the genome. Epigenetics studies heritable characteristics that influence gene expression through mechanisms other than alterations of a DNA sequence. Epigenetics decodes how environmental factors influence the expression and function of genes, contributing to health or illness.
Although many diseases, disorders, and conditions are classified as “genetic,” this simply means that there is an identified genetic component to its origin or expression. Medical geneticists contend that most diseases can’t be classified as strictly genetic or environmental. The expression of a genetic disease can sometimes be altered, even to the point of complete suppression, by environmental factors. Similarly, diseases due to infectious pathogens may not be expressed because of a genetic predisposition for a protective immune response. Each disorder, in each individual, exists along a continuum spanning a range of genetic and environmental causes.
Today, in the third decade of the twenty-first century, the great promise of genomic medicine is to make preventive measures more powerful and treatment more specific to the individual, enabling investigation and treatments that are custom-tailored to an individual’s genetic susceptibilities or to the characteristics of the specific disease or disorder.
Genomic sequencing decoded the genes of SARS-CoV-2, the virus that causes COVID-19, enabling scientists to detect and monitor the spread of genetic variants. The mRNA (messenger RNA) technology used to create lifesaving COVID-19 vaccines encodes information that teaches the body to synthesize harmless antigens that mimic vulnerable portions of the actual virus, stimulating the body’s production of virus-neutralizing antibodies. This technology is being applied to develop vaccines and treatments for a wide range of pathogens—from HIV, Zika, malaria, and tuberculosis to influenza and cancer—in less time and at lower costs than traditional methods.
The Gale Encyclopedia of Genetic Disorders, 5th edition, aims to educate readers about the origins of genetic disorders and the promise and progress made to detect and treat them. We hope it will inspire discussion and debate about wise and judicious use of genetic and genomic research and technologies.
[Adapted from the “Foreword” to The Gale Encyclopedia of Genetic Disorders, 5th edition, by Barbara Wexler.]