title: Current therapies for Morquio A syndrome and their clinical outcomes.
abstract: BACKGROUND
  Morquio A syndrome is characterized by a unique skeletal dysplasia, leading to short neck and trunk, pectus carinatum, laxity of joints, kyphoscoliosis, and tracheal obstruction. Cervical spinal cord compression/inability, a restrictive and obstructive airway, and/or bone deformity and imbalance of growth, are life-threatening to Morquio A patients, leading to a high morbidity and mortality. It is critical to review the current therapeutic approaches with respect to their efficacy and limitations.
  
  
  METHODS
  Patients with progressive skeletal dysplasia often need to undergo orthopedic surgical interventions in the first two decades of life. Recently, we have treated four patients with a new surgery to correct progressive tracheal obstruction. Enzyme replacement therapy (ERT) has been approved clinically. Cell-based therapies such as hematopoietic stem cell therapy (HSCT) and gene therapy are typically one-time, permanent treatments for enzyme deficiencies. We report here on four Morquio A patients treated with HSCT approved in Japan and followed for at least ten years after treatment. Gene therapy is under investigation on mouse models but not yet available as a therapeutic option.
  
  
  CONCLUSIONS
  ERT and HSCT in combination with surgical intervention(s) are a therapeutic option for Morquio A; however, the approach for bone and cartilage lesion remains an unmet challenge.
authors.affiliation: Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, USA.
authors.forename: Kazuki
authors.initials: K
authors.lastname: Sawamoto
authors.affiliation: Medical Education Development Center, Gifu University, Gifu, Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Suzuki
authors.affiliation: Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, USA.
authors.forename: William G
authors.initials: WG
authors.lastname: Mackenzie
authors.affiliation: Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, USA.
authors.forename: Mary C
authors.initials: MC
authors.lastname: Theroux
authors.affiliation: Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, USA.
authors.forename: Christian
authors.initials: C
authors.lastname: Pizarro
authors.affiliation: Department of Cell Transplantation and Regenerative Medicine, Tokai University School of Medicine, Isehara, Japan.
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Yabe
authors.affiliation: Division of Neonatal Intensive Care Unit, Gifu University Hospital, Gifu, Japan.
authors.forename: Kenji E
authors.initials: KE
authors.lastname: Orii
authors.affiliation: Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, USA.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Mason
authors.affiliation: Department of Pediatrics, Gifu University, Gifu, Japan.
authors.forename: Tadao
authors.initials: T
authors.lastname: Orii
authors.affiliation: Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, USA; Department of Pediatrics, Gifu University, Gifu, Japan.
authors.forename: Shunji
authors.initials: S
authors.lastname: Tomatsu
keywords: ERT; HSCT; Morquio A; gene therapy; orthopedic surgery; tracheal obstruction