The 22q11.2 deletion syndrome (22q11DS) is a chromosomal disorder designated as an incurable disease that can be complicated by physical, intellectual, and psychiatric disorders. This syndrome is becoming especially well known among Japanese psychiatrists because it may cause schizophrenia-like psychotic symptoms. Most previous studies in the field have been limited to case reports focusing on diagnosis and treatment. Although guidelines do exist from the perspective of lifelong medical care for congenital heart disease, the psychosocial difficulties of individuals and their families have not been fully understood. The syndrome is highly heterogeneous, and the phenotype within individuals may change with age, including congenital physical disease, intellectual disability affecting learning during the school years, and development of mental disorders after puberty. The combination of multimorbidity characteristics and changes to the living environment during life stages creates multilayered difficulties. However, routine support in divided social systems is often inadequate. While focusing on the welfare system, the present study aims to clarify difficulties and identify necessary support required due to the mismatch between disease traits and social systems. The method used was a web-based survey of 125 caregivers. A mixed research method was adopted to conduct quantitative analysis of the selected responses and qualitative analysis of the open-ended responses. The quantitative analysis showed that the diversity of difficulties changed with age: younger individuals tended to have difficulties related to medical care and education, and older individuals tended to have difficulties related to employment, marriage, and housing. The lack of consideration for overlapping disabilities decreased from early childhood to school age but increased again at age 19 and above. In the qualitative analysis, several themes were identified that were not included in the quantitative analysis, such as the psychological aspects of the individual and family and the specific support required. In both quantitative and qualitative analyses, lack of knowledge and understanding of the disease by professionals was a point raised by many respondents. Evidently, a need exists for flexible support that is not bound by existing institutional design and is based on understanding of the disease and the diverse difficulties and needs associated with it.
 Authors' abstract