A Community-Based Study of Mucopolysaccharidosis Type VI in Brazil: The Influence of Founder Effect, Endogamy and Consanguinity

Mucopolysaccharidosis type VI (MPS VI - Maroteaux-Lamy syndrome) is a globally rare lysosomal storage disease caused by a deficiency of arylsulfatase B. However, in Monte Santo, a poor and isolated rural region in Northeast Brazil with large family sizes and high rates of community endogamy and pa- rental consanguinity (α = 0.00483), 9 living and 4 now de- ceased individuals in 11 kindreds have been diagnosed with MPS VI, all with the same p.H178L missense founder muta- tion. A further 33 deceased persons have been identified by family members as exhibiting the disease phenotype. De- tailed pedigrees were constructed for the 13 genomically confirmed MPS VI patients, with blood samples collected from 236 unaffected family members to determine the prev- alence of the p.H178L mutation. A total of 98 (20.8%) mutant