Impact of Mucopolysaccharidosis Type II in Young Children from the Caregiver’s Perspective: A Qualitative Study

INTRODUCTION: Mucopolysaccharidosis type II (MPS II), also known as Hunter syndrome, is a rare, progressive X-linked lysosomal storage disorder that clinically manifests in children around 2-4 years of age. It affects nearly all organ systems, and in about two-thirds of patients, follows a severe neuronopathic course marked by developmental delay and cognitive decline. This study examined caregivers' perspectives on the most important symptoms and impacts of MPS II in young children. METHODS: Caregivers of children aged 2-5 years with MPS II in the UK or USA were interviewed about the symptoms and impacts of MPS II in their child using a concept elicitation approach. A content analysis approach was used to analyze qualitative data collected. RESULTS: Sixteen caregivers (n = 13 USA, n = 3 UK; mean age 34.0 years) of 16 children with MPS II participated. All 15 children for whom sociodemographic data were available were male and neuronopathic (mean age 4.2 years). All 16 caregivers reported cognitive decline in their child and disruption of family life. Other areas where MPS II burdens their children included problems with verbal communication/speech (n = 15), walking/climbing stairs (n = 15), hand movement (n = 15), hearing loss (n = 15), infection (n = 15), frustration (n = 14), interaction with non-family members (n = 14), nonverbal communication (n = 13), endurance (n = 13), stiff joints or muscles (n = 13), incontinence (n = 12), and skin issues (n = 10). Caregivers considered communication, mobility, and joint and muscle issues the "most bothersome" impacts. CONCLUSION: Despite the availability of enzyme replacement therapy since 2006, MPS II substantially affects the lives of young children and their families.