Individual experiences and issues in predictive genetic testing for untreatable hereditary neuromuscular diseases in Japan.

Predictive genetic testing (PT) for hereditary diseases that do not have effective treatment or prevention strategies places a psychological burden on parties and their families. There has been little research on the psychosocial aspects of PT in Japan, nor are there any guidelines. To address this gap, we conducted a questionnaire survey of parties at genetic risk for untreatable hereditary neuromuscular diseases, and the National Liaison Conference of Genetic Medicine Departments (GMDs). Of the 63 parties who responded to the survey, 10 (15.9%) had undergone PT. Of the 67 GMDs, only 18 facilities (26.9%) were conducting PT with written procedures. At least two of the six parties with such results felt that some follow-up would be helpful. One party had taken PT for preimplantation genetic testing for monogenic (PGT-M); four, who had no experience, provided free text responses indicating that PGT-M or prenatal genetic testing was chosen as a motivation. Eight were unaware of PT, and six were unaware of their blood relatives' diseases being "hereditary." The results highlighted the need to: 1) develop guidelines for PT in untreatable hereditary diseases; 2) provide access to PT information; and 3) share the "heritability" of diseases with family and relatives.