[Preimplantation Genetic Testing for Monogenic Disorders: The Role of Neurologists and Challenges]

Preimplantation genetic testing for monogenic disorders (PGT-M) has been implemented in Japan under a novel definition of severity to reduce the chances of giving birth to a child with an inherited genetic disorder. The redefinition of disease severity is not only about changing definitions and interpretations, but also a matter of potentially expanding the number of diseases covered by PGT-M and the range of clients, which could raise serious human rights-related issues. With the rapid development of therapies for neuromuscular diseases and the possibility of the clinical course of diseases previously considered to be serious becoming progressively becoming milder in the future, the "definition of severity" classification itself, as applied to PGT-M, may become debatable. Neurologists will thus become more involved in presymptomatic diagnosis and newborn screening for the early diagnosis and treatment to enhance the efficacy of new therapies. We also need to address the technical, social, and ethical issues surrounding genetic counselling and PGT-M, and practice holistic medicine for the patients and their families.