Techniques for the Diagnosis of Rare Genetic Disorders

Rare genetic disorders are hereditary conditions brought on by changes or mutations in a person’s DNA. A few people are affected by these illnesses, often inherited from parents with mutant genes. Rare diseases afflict more than 300–400 million people worldwide, including 30 million in the United States, and often result in chronic illness, disability, and premature death. Using heuristic approaches to diagnose rare diseases is a common practice based on clinical experience and medical literature. Diagnosing rare diseases remains challenging, regardless of their prevalence in clinical practice. Patients with rare diseases are often left undiagnosed for years, and many do not receive a correct diagnosis before they die. But still, improvements in genetic testing and research are improving the understanding of these disorders and raising the potential for identifying effective therapies and remedies. Molecular identification of rare and undiagnosed diseases has been made possible by gene panels, microarrays, and exome sequencing in recent years. New diagnostic approaches based on next-generation sequencing (NGS) technology have made it possible to diagnose genetically heterogeneous disorders, even when clinical diagnostic hypotheses are unclear. While new technologies are used extensively in many health facilities and health systems, their use is significantly different. This chapter provides clinicians and researchers with strategies for a group of rare hereditary diseases brought on by genetic abnormalities, which only affect a minor portion of the population. The rarity of these conditions and the wide variety of symptoms they might present make things more complicated. The precision and rapidity of diagnosis have increased due to genetic testing technology developments.