The fourth-generation sequencing system demonstrates remarkable advantages in genetic disease research, providing powerful technical support for the study of hereditary conditions such as Fragile X syndrome, Huntington's disease, and Spinal Muscular Atrophy (SMA). Long-read sequencing combined with circular consensus correction of patient genomes enables precise identification of pathogenic genes. This aids scientists and clinicians in better understanding the mechanisms underlying genetic diseases, thus offering robust data support for the development of gene therapy and precision medicine. These applications propel the prospects of the fourth-generation sequencing system to new heights in the field of medical genetics.