title: [Clinical and genetic features of X-linked Alport syndrome in men positive for the collagen Ⅳ α5 chain in epidermal basement membrane].
abstract: OBJECTIVE
  To analyze the clinical and genetic features of X-linked Alport syndrome (XLAS) in men positive for the collagen α5(Ⅳ) chain in epidermal basement membrane.
  
  
  METHODS
  This was a retrospective study. Totally 725 families were diagnosed as Alport syndrome in Department of Pediatrics of Peking University First Hospital during January 1998 to December 2014, among them 450 patients were males with XLAS. Patients who met both of the following two criteria were included in this study. (1)Patients underwent α5(Ⅳ) chain staining in the epidermal basement membrane. (2)Mutations in COL4A5 gene were detected.Mann-Whitney test and χ(2) test were used.
  
  
  RESULTS
  Totally 140 males with XLAS were included in this study, 18 cases were α5 (Ⅳ)-positive and 122 cases were α5 (Ⅳ)-negative. The two groups of patients were compared, the median age at analysis was 11.0 vs. 7.2 years (Z = -1.839, P = 0.066), the 24-hour urine protein was 1.50 vs. 0.57 g/d (Z = -1.212, P = 0.226), the rate of hearing loss was 28% vs. 53% (χ(2) = 3.619, P = 0.067), the number of patients progressed to end stage renal disease (ESRD) was 4 vs. 12 (χ(2) =2.377, P = 0.128), the median age of ESRD was 31.0 vs. 16.6 years (Z = -2.554, P = 0.011), the rate of missense mutations in COL4A5 gene was 67% vs. 52% (χ(2) = 1.424, P = 0.313).
  
  
  CONCLUSIONS
  Compared the two groups of patients with positive and negative staining for the collagen Ⅳ α5 chain in epidermal basement membrane, there was no significant difference in the proteinuria level, the rate of hearing loss and genotype of COL4A5 gene. But the patients with positive staining progressed to ESRD significantly later than the patients with negative staining.
authors.affiliation: Department of Pediatrics, Peking University First Hospital, Beijing 100034, China.
authors.forename: Yanqin
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jie
authors.initials: J
authors.lastname: Ding
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
authors.forename: Hongwen
authors.initials: H
authors.lastname: Zhang
authors.forename: Huijie
authors.initials: H
authors.lastname: Xiao
authors.forename: Yong
authors.initials: Y
authors.lastname: Yao
authors.forename: Xuhui
authors.initials: X
authors.lastname: Zhong
authors.forename: Na
authors.initials: N
authors.lastname: Guan
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Liu
authors.forename: Lixia
authors.initials: L
authors.lastname: Yu
authors.forename: Jingcheng
authors.initials: J
authors.lastname: Liu
authors.forename: Jiyun
authors.initials: J
authors.lastname: Yang
mesh_terms: D001485:Basement Membrane / Q000473:pathology*; D002648:Child; D024141:Collagen Type IV / Q000235:genetics*; D004252:DNA Mutational Analysis; D003638:Deafness; D006801:Humans; D007676:Kidney Failure, Chronic; D008297:Male; D020125:Mutation, Missense; D009394:Nephritis, Hereditary / Q000235:genetics* / Q000473:pathology*; D011507:Proteinuria; D012189:Retrospective Studies
chemical_list: C478159:COL4A5 protein, human; D024141:Collagen Type IV