Patient Characterization before and after enzyme therapy.The GALNS p.Gly301Cys variant is a probable founder mutation from the coffee-growing area of ​​Colombia that causes mucopolysaccharidosis IVA syndrome.

Background: Mucopolysaccharidosis IVA (Morquio A syndrome, MPS IVA) is an autosomal recessive lysosomal storage disorder caused by biallelic variants in the N-acetylgalactoseamine-6-sulfate sulfatase (GALNS) gene (1). The prevalence for Colombia is 1 to 1.98 per 100,000 to 147,000 live births(2). Our objective was to evaluate pain before and after receiving enzymatic therapy in patients with the p.Gly301Cys variant present in the GALNS gene among the population of the coffee-growing area, central-western Colombia.. Metodology We included patients with p. Gly301Cys variant present in the GALNS gene amongst the population of Coffee area. . we evaluated according to the recommendations of the International Guidelines for the Management and Treatment of Morquio Syndrome (3). Pain scale Modified Brief Pain Inventory -Short form (mBPI) y Wong Baker, and Quality life survey analysis before and after enzymatic therapy. Results A total of 23 patients, 11 women, 12 men, 39% were children. Median age was 21.7 years. 21 patients presented the variant p.GLy301Cys in homozygosis With severe phenotype in 100% with corneal opacity, pectus carinatum, genu valgus. 100% with corneal opacity, pectus carinatum, genuvalgo, Walk test in 6 minutes better in young people. 14 patients have cardiac involvement (most frequent mitral valve disease). All patients have some degree of hearing loss. The severity and interference of pain was lower in the group with diagnosis and initiation of enzyme therapy in childhood. Two patients with mild phenotype with heterozygosity p.Gly301Cys/p.Gly333Asp, and p.Gly301Cys/p.Trp325Ter without corneal opacity, pectus carinatum, or genu valgus, with normal lung function, without heart disease Discussion/Conclusion The p.Gly301Cys variant in the GALNS gene is present in the population of the Coffee Region, Colombia with a founder mutation. An interdisciplinary approach is required(3). Enzyme therapy improves pain in children and adults with this mutation, improving quality of life.