Epidemiological Features of Costello and CFC Syndromes

Department of Medical Genetics, Tohoku University School of Medicine, Sendai, Japan

Only a few Japanese patients with Costello and CFC syndromes had been reported by 2005. The number of patients is growing after the identification of causative genes for these disorders. However, clinico-epidemiological features of these disorders remain to be elucidated. In order to assess the prevalence, natural history, prognosis and tumor incidence, we conducted a nationwide prevalence study of patients with Costello and CFC syndromes in Japan. The protocol we followed has been established by study groups on intractable diseases granted by the Ministry of Health and Welfare of Japan. The prevalence of intractable diseases, including moyamoya disease, pancreatitis and sudden deafness has been reported using the same protocol. The study consisted of a two-stage questionnaire survey. The first-stage survey inquired the number of mutation-positive patients as well as clinically suspected patients. The second-stage survey asked for detailed clinicoepidemiological information of each patient reported. The estimated number of patients, prevalence, clinical manifestations of mutation-positive patients and activities of daily living were clarified in this study. Evaluation of fifteen adult patients aged 18-32 years revealed that twelve patients had moderate to severe mental retardation, but eleven of them live at home and ten can walk independently, suggesting that the number of adult patients were underestimated. This is the first epidemiological study of both disorders. Identification of patients older than 32 years of age and follow up of the reported patients in the current study will be important to estimate the precise prevalence and natural history of these disorders.