Ana Ximena Navarro is pictured at her home in Guadalajara, Mexico on February 22, 2017. Ximena was diagnosed as an infant with Hurler syndrome. Hurler syndrome is the most severe form of mucopolysaccharidosis type 1 (MPS1), a rare lysosomal storage disease, characterized by skeletal abnormalities, cognitive impairment, heart disease, respiratory problems, enlarged liver and spleen, characteristic facies and reduced life expectancy. Ximena was being given enzyme replacement therapy (ERT) when she was 19 months old, and she was suddenly able to eat and sleep. She is now 12, and has normal hormonal development for her age, although some mental delay, according to her father. “Without the treatment, she would have died from all the complications — untreated, children have a very bad quality of life and typically die before they are seven”, her father says. Photo credit: Bénédicte Desrus