[Prevalence of the Phelan-McDermid Syndrome in Spain.]

Objective: Phelan-McDermid syndrome is a rare genetic condition caused by a deletion of the terminal end of chromosome 22 in the 13.3 region, as well as, by point mutations within SHANK3 gene. The aims of this research were to determine the prevalence of the disease in the Spanish population, to establish the geographical distribution of the syndrome among the different autonomous communities, to elucidate the age range that affects more patients, to study the disease-sex relationship, as well as the age at diagnosis.

Methods: For the research, patients diagnosed with the disease for twelve years were recruited throughout the Spanish territory. The clinical patient information was obtained from the referral doctors using two standardized questionnaires completed with data from the medical reports and the interview with the parents. The molecular diagnosis of the disease was carried out using different formats of microarrays. Data were processed using Microsoft Excel and Statgraphics Centurion XVII.

Results: Currently in Spain there are 201 people diagnosed with the disease. Currently in Spain there are 201 people diagnosed with the disease, its prevalence being 4x10^-4/10,000 inhabitants. The community with the most diagnosed patients was Madrid and there were no significant differences in terms of sex and disease, the mean age at diagnosis was around 6.67 years.

Conclusions: The prevalence of the disease in Spain is very low, and it can be stated that it is very likely that there are more people with this syndrome in the population.