486 - Quality of Life: An Important Consideration among Children with Morquio A Syndrome

Publication Number: 1466.486

Melissa A. Alderfer, Nemours Children's Hospital, Delaware, Media, PA, United States; Amanda Lewis, Nemours Children's Hospital, Wilmington, DE, United States; Kimberly Klipner, Nemours Children's Health-Delaware, Wilmington, DE, United States; Marie Sahou, Nemours Children's Hospital, Bear, DE, United States; Yasuhiko Ago, Nemours Children's Hospital, Wilmington, DE, United States; Shunji Tomatsu, NemoursAlfred I. duPont Hospital for Children, Wilmington, DE, United States

Background: Morquio A syndrome, or Mucopolysaccharidosis Type IVA (MPS-IVA), is a rare, progressive genetic disorder characterized by advancing systemic skeletal dysplasia, including kyphosis, chest protrusion, genu valgum, short-trunk dwarfism, joint hyperlaxity, abnormal gait, and impaired endurance. While enzyme replacement therapy is the current standard of care, improving endurance, new therapies are emerging and additional outcomes need to be considered, including quality of life.

Objective: We assessed quality of life among children with MPS-IVA from both self- and caregiver-reports to: 1) explore if the measures used would be viable for future clinical trials; and, 2) compare resulting ratings with published reports of other groups (i.e., healthy children and those with rheumatic diseases).

Design/Methods: As part of an IRB-approved observational longitudinal study with various non-invasive functional assessments, patients with MPS-IVA and, for those aged 2-17, their caregivers, completed the Pediatric Quality of Life Generic Scale (PedsQL 4.0) and the PedsQL Rheumatology Module and Multidimensional Fatigue Scale. Scores range from 0 to 100; higher scores indicate a better quality of life. Baseline (study entry) data were summarized with descriptive statistics to address Aim 1, and t-tests with alpha correction (p <.005) were used to address Aim 2.

Results: To date, 37 families with 41 children with MPS IVA aged 2-17 have enrolled in the study (74% of those approached). As shown in Table 1, means and medians were relatively consistent across reporters; ranges and skew statistics suggest good variability with few instances of ceiling effects. Tables 2 and 3 provide self-reported and caregiver-reported QOL, respectively, along with published data for similarly-aged comparison groups. Compared to healthy children, our sample had lower QOL scores across all Generic and Fatigue scales, except for self-reported sleep/rest. In comparison to children with rheumatic diseases, our sample had poorer QOL in physical, social, daily activities, and treatment domains, but not in emotional, worry, communication, pain, school, and most fatigue domains.

Conclusion(s): Children with MPS-IVA seem to have QOL deficits compared to healthy children in nearly all areas measured. They also have some physical, functional, and social deficits compared to children with rheumatic diseases, but no significant differences in emotional, academic, pain or most fatigue QOL scales. The PedsQL Generic, Rheumatology, and Multidimensional Fatigue Scales may be useful tools for assessing outcomes of interest for MPS IVA treatment studies.

Table 1. Descriptive Statistics for each PedsQL Scale by Reporter
Notes: (1) 41 responses were possible for all parent-report scales except for the Worry and Communication subscales (not applicable for toddlers) where 32 responses were possible. (2) 32 responses were possible for all self-report scales except for the Fatigue scale (not administered to young children) where 21 responses were possible.

Table 2. Self-reported Quality of Life for 5- to 17-year-olds with MPS-IVA compared to other published samples
Notes: (1) 232 children attending the pediatric rheumatology clinical at Children's Hospital and Health Center, San Diego provided data on the Generic and Rheumatology Scales as reported in Varni et al., 2002 and a separate sample of 163 children attending the same clinic provided data on the Fatigue Scale as reported in Varni, Burwinkle & Szer, 2004. (2) 401 children presenting at pediatrician offices for scheduled well child checks or seen as inpatients or outpatients at least 3 months prior to recruitment provided data on the Generic Scale as reported in Varni, Seid, and Kurtin, 2001 and 52 children who had attended an orthopedic clinic for broken bones or fractures 6 months prior to assessment completed the Fatigue Scale as reported in Varni, Burwinkle & Szer, 2004.

Table 3. Caregiver-reported Quality of Life for 2- to 17-year-olds with MPS-IVA compared to other published samples
Notes: (1) Caregivers of 272 children attending the pediatric rheumatology clinical at Children's Hospital and Health Center, San Diego provided data on the Generic and Rheumatology Scales as reported in Varni et al., 2002 and a separate sample of caregivers of 154 children attending the same clinic provided data on the Fatigue Scale as reported in Varni, Burwinkle & Szer, 2004. (2) Caregivers of 730 children presenting at pediatrician offices for scheduled well child checks or seen as inpatients or outpatients at least 3 months prior to recruitment provided data on the Generic Scale as reported in Varni, Seid, & Kurtin, 2001 and caregivers of 102 children who had attended an orthopedic clinic for broken bones or fractures 6 months prior to assessment completed the Fatigue Scale as reported in Varni, Burwinkle & Szer, 2004.