A nationwide survey of Vici syndrome in Japan

Vici syndrome (VICIS) is a congenital disorder characterized by agenesis of the corpus callosum, cataracts, hypopigmentation, cardiomyopathy, combined immunodeficiency, microcephaly, and failure to thrive. This study aimed to elucidate the number of patients with VICIS, its clinical characteristics and relevant genetic information in Japan. After developing diagnostic criteria for VICIS, we conducted a nationwide questionnaire-based survey of VICIS in Japan. In the initial survey, we investigated the number of VICIS patients who fulfilled definite or probable criteria. The second survey was used to obtain detailed clinical and genetic information of VICIS from institutions that responded to the initial survey. Clinical information was available for 15 patients (12 definite, three probable). As of October 2023, nine patients (60%) were alive and six (40%) had died. All patients presented with developmental delay, agenesis of the corpus callosum, elevated serum aspartate/alanine aminotransferase, hypopigmentation and hypotonia. Developmental delay was profound. Most patients developed recurrent infection, high-arched palate, epilepsy, failure to thrive, and microcephaly. Cardiomyopathy and cataracts, both initially described as principal features in VICIS, were notably uncommon in our study. Based on the information collected, all 14 patients for whom information was available received home medical care: 11 (79%) received tube feeding, three (21%) required noninvasive ventilation, four (29%) required tracheostomy, and four (29%) required home subcutaneous immunoglobulin administration. This study revealed for the first time the nationwide status of patients with VICIS in Japan. The mortality rate of patients with VICIS is as high as 40%, and almost all VICIS patients require various forms of home medical care, necessitating comprehensive management. Additionally, we identified one adult patient, underscoring the need for comprehensive medical management extending into adulthood for patients with VICIS.