title: Causes of death and clinical characteristics of 34 patients with Mucopolysaccharidosis II in Taiwan from 1995-2012.
abstract: Mucopolysaccharidosis type II (MPS II) is an X-linked recessive, multisystemic lysosomal storage disorder caused by a deficiency of iduronate-2-sulfatase. MPS II has a variable age of onset and variable rate of progression. In Asian countries, there is a relatively higher incidence of MPS II compared to other types of MPS.
  
  
  
  A retrospective analysis was carried out of 34 Taiwanese MPS II patients who died between 1995 and 2012. The clinical characteristics, medical records, age at death, and cause of death were evaluated to better understand the natural progression of this disease.
  
  
  
  The mean age at death of 31 of the patients with a severe form of the disease with significant cognitive impairment was 13.2 ± 3.2 years, compared with 22.6 ± 4.3 years in the three patients with a mild form of the disease without cognitive involvement (n = 2) or the intermediate form (n = 1) (p < 0.001). The mean ages at onset of symptoms and confirmed diagnosis were 2.5 ± 2.1 and 4.8 ± 3.1 years, respectively (n = 32). Respiratory failure was the leading cause of death (56 %), followed by cardiac failure (18 %), post-traumatic organ failure (3 %), and infection (sepsis) (3 %) (n = 27). Age at onset of symptoms was positively correlated with life expectancy (p < 0.01). Longevity gradually increased over time from 1995 to 2012 (p < 0.05).
  
  
  
  Respiratory failure and cardiac failure were the two major causes of death in these patients. The life expectancy of Taiwanese MPS II patients has improved in recent decade.
authors.affiliation: Department of Medicine, Mackay Medical College, New Taipei City, Taiwan.|Department of Pediatrics, Mackay Memorial Hospital, No. 92, Sec. 2, Chung-Shan North Road, Taipei, 10449, Taiwan.|Department of Medical Research, Mackay Memorial Hospital, Taipei, Taiwan.|Mackay Junior College of Medicine, Nursing and Management, Taipei, Taiwan.|Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Hsiang-Yu
authors.initials: HY
authors.lastname: Lin
authors.affiliation: Department of Medical Research, Mackay Memorial Hospital, Taipei, Taiwan.|Medical College, Fu-Jen Catholic University, Taipei, Taiwan.|Institute of Biotechnology, National Taipei University of Technology, Taipei, Taiwan.
authors.forename: Chih-Kuang
authors.initials: CK
authors.lastname: Chuang
authors.affiliation: Department of Pediatrics, Mackay Memorial Hospital, No. 92, Sec. 2, Chung-Shan North Road, Taipei, 10449, Taiwan.
authors.forename: Yu-Hsiu
authors.initials: YH
authors.lastname: Huang
authors.affiliation: Department of Medical Research, Mackay Memorial Hospital, Taipei, Taiwan.
authors.forename: Ru-Yi
authors.initials: RY
authors.lastname: Tu
authors.affiliation: Department of Pediatrics, Mackay Memorial Hospital, No. 92, Sec. 2, Chung-Shan North Road, Taipei, 10449, Taiwan.
authors.forename: Fang-Ju
authors.initials: FJ
authors.lastname: Lin
authors.affiliation: Department of Pediatrics, Chi Mei Medical Center, Tainan, Taiwan.
authors.forename: Shio Jean
authors.initials: SJ
authors.lastname: Lin
authors.affiliation: Department of Pediatrics, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan.
authors.forename: Pao Chin
authors.initials: PC
authors.lastname: Chiu
authors.affiliation: Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan.|Department of Pediatrics, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Dau-Ming
authors.initials: DM
authors.lastname: Niu
authors.affiliation: Department of Pediatrics, China Medical University Hospital, Taichung, Taiwan.
authors.forename: Fuu-Jen
authors.initials: FJ
authors.lastname: Tsai
authors.affiliation: Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Wuh-Liang
authors.initials: WL
authors.lastname: Hwu
authors.affiliation: Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Yin-Hsiu
authors.initials: YH
authors.lastname: Chien
authors.affiliation: Division of Medical Genetics, Department of Pediatrics, Chang Gung Memorial Hospital at Linkou and Chang Gung University College of Medicine, Taoyuan, Taiwan.
authors.forename: Ju-Li
authors.initials: JL
authors.lastname: Lin
authors.affiliation: Department of Pediatrics, National Cheng Kung University Hospital, Tainan, Taiwan.
authors.forename: Yen-Yin
authors.initials: YY
authors.lastname: Chou
authors.affiliation: Department of Pediatrics, Chi Mei Medical Center, Tainan, Taiwan.
authors.forename: Wen-Hui
authors.initials: WH
authors.lastname: Tsai
authors.affiliation: Department of Pediatric Neurology, Changhua Christian Children's Hospital, Changhua, Taiwan.
authors.forename: Tung-Ming
authors.initials: TM
authors.lastname: Chang
authors.affiliation: Department of Medicine, Mackay Medical College, New Taipei City, Taiwan. 4535lin@gmail.com.|Department of Pediatrics, Mackay Memorial Hospital, No. 92, Sec. 2, Chung-Shan North Road, Taipei, 10449, Taiwan. 4535lin@gmail.com.|Department of Medical Research, Mackay Memorial Hospital, Taipei, Taiwan. 4535lin@gmail.com.|Department of Infant and Child Care, National Taipei University of Nursing and Health Sciences, Taipei, Taiwan. 4535lin@gmail.com.
authors.forename: Shuan-Pei
authors.initials: SP
authors.lastname: Lin
mesh_terms: D000293:Adolescent; D000328:Adult; D002423:Cause of Death; D002648:Child; D005260:Female; D006801:Humans; D008017:Life Expectancy; D008297:Male; D016532:Mucopolysaccharidosis II / Q000175:diagnosis / Q000401:mortality* / Q000473:pathology*; D012189:Retrospective Studies; D013624:Taiwan; D055815:Young Adult
keywords: Cause of death; Hunter syndrome; Mortality; Mucopolysaccharidosis II; Taiwan