Identification of MPS clusters in Latin America: An opportunity for targeted health care programs

The mucopolysaccharidoses (MPS) include 11 rare disorders caused by deficiency of specific lysosomal enzymes resulting in the accumulation of undegraded glycosaminoglycans (GAGs) and several clinical consequences. The combined incidence for all MPS subtypes is approximately 1:25,000 live births. Clusters of these diseases have been identified in areas with high consanguinity and/or founder effect associated to endogamy. The MPS Brazil Network, associated to the Brazilian Institute of Population Medical Genetics, identified several MPS clusters in Latin America. Three clusters were confirmed in Brazil, of MPS IIIC (state of Paraiba), MPS IVA (state of Paraiba) and MPS VI (state of Bahia). Two clusters were identified in Ecuador: MPS IIIB (state of Manabi) and MPS IVA (state of Pastaza). A cluster of MPS VI was also identified in the Dominican Republic. Other clusters are being investigated in Haiti (MPS VI), Panama (MPS IVA), and Brazil (MPS IIIB, Minas Gerais state). Haplotype analyses are underway to better characterize mutation profiles, and results already available for the clusters of MPS IVA and MPS VI in Brazil indicate founder effects with common ancestors. As one example of the benefits of cluster identification, a newborn screening program for MPS VI was implemented in the Brazilian region in order to provide early identification and treatment of new patients. In conclusion, examples of MPS clusters were identified in Latin America and it is likely that several others are still unreported. We aim to properly identify and characterize MPS clusters in Latin America, to better understand how they were originated and to be able to offer targeted preventive and management measures to the affected communities (Acknowledgements to the MPS Brazil Network, especially to Fernanda Bender, Fernanda Bittencourt, Diana Rojas Malaga, Aline Nemetz Bochernitsan, Jurema de Mari, and Franciele Barbosa Trapp).