Editorial: As preimplantation gene tests increase in Japan, open and broad debate needed

Preimplantation genetic diagnosis (PGD) of embryos can be called a decision of life and death. As the technique begins to spread in Japan, it must proceed transparently and with great care.

PGD involves testing embryos created through in-vitro fertilization (IVF) using to-be parents’ sperm and eggs before it is implanted into the uterus. Diagnostics check for the presence of serious, inheritable conditions, and those without any abnormalities are selected to be placed back into the uterus.

The Japan Society of Obstetrics and Gynecology (JSOG), which is responsible for screening PDG requests, has released details on applications in 2023. There were 72 requests, tripling the heretofore yearly average of 24. Of these, 58 were approved.

Behind the increasing number of requests was a rule change by the organization in 2022 which broadened eligibility. Until then, only serious genetic disorders such as those which would require artificial respiration or cause death before adulthood were covered. The new rules allow for exceptions to this.

The cases approved in 2023 included those with conditions such as a disease of gradual muscle atrophy in adulthood and an eye cancer which has an over 90% survival rate even when occurring in childhood.

A JSOG panel which includes experts in genetic disorders reviews cases one by one. There have been cases in which couples presenting the same disorder have been approved or not depending on their circumstances, but due to privacy issues the exact reasons were not announced. Failing to provide the rationale, however, can only invite confusion.

From the start, there have been limits to entrusting the JSOG with the ability to judge individual cases or draw a line regarding what counts as a serious condition. Creating a public framework may be in the best interests of fairness and transparency.

Since PGD allows the testing of diseases for not-yet born children before a pregnancy begins, there is no small number of couples having a child with a genetic disorder and facing a wide range of problems who wish to be tested.

Through PGD, fertilized eggs in which conditions are detected are disposed of. If the process gains traction, effects could include discrimination against people with illness or disability and the promotion of eugenics. Prenatal diagnostics, such as testing the would-be mother’s blood or amniotic fluid for the presence of fetal illness, involves the same kind of problems.

The most important thing is to change the status quo whereby those with illness or disabilities find it difficult to lead their lives. We must continue to work toward building a society where all people can live with peace of mind.