Abstract: Rare diseases, also known as “orphan diseases”,  are difficult to diagnose and treat because of the extremely  low incidence of single diseases and scattered cases. About 80% of rare diseases are caused by genetic defects. Accurate diagnosis and treatment of rare diseasedependent gene levels, and research on rare diseases from a genetic perspective are  the focus of current medical research. This article reviews the general situation of rare diseases, gene diagnosis technology of rare diseases, gene therapy, preimplantation genetic diagnosis/screening technology, prenatal diagnosis, neonatal screening and so on,  aiming to show the progress of diagnosis and treatment of rare diseases from the perspective of heredity.

Key words: rare diseases, second generation sequencing technology, preimplantation diagnosis, gene therapy