Mutational characterization of the P3H1/CRTAP/CypB complex in recessive osteogenesis imperfecta

Abstract

ABSTRACT. Osteogenesis imperfecta (OI) is a genetic disease characterized by bone deformities and fractures. Most cases are caused by autosomal dominant mutations in the type I collagen genes COL1A1 and COL1A2; however, an increasing number of recessive mutations in other genes have been reported. The LEPRE1, CRTAP, and PPIB genes encode proteins that form the P3H1/CRTAP/CypB complex, which is responsible for posttranslational modifications of type I collagen. In general, mutations in these genes lead to severe and lethal phenotypes of recessive OI. Here, we describe sixteen genetic variations detected in LEPRE1, CRTAP, and PPIB from 25 Brazilian patients with OI. Samples were screened for mutations on single-strand conformation polymorphism gels and variants were determined by automated sequencing. Seven variants were detected 15849 P3H1/CRTAP/CyPB and osteogenesis imperfecta ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 14 (4): 15848-15858 (2015) in patients but were absent in control samples. LEPRE1 contained the highest number of variants, including the previously described West African allele (c.1080+1G>T) found in one patient with severe OI as well as a previously undescribed p.Trp675Leu change that is predicted to be disease causing. In CRTAP, one patient carried the c.558A>G homozygous mutation, predicted as disease causing through alteration of a splice site. Genetic variations detected in the PPIB gene are probably not pathogenic due to their localization or because of their synonymous effect. This study enhances our knowledge about the mutational pattern of the LEPRE1, CRTAP, and PPIB genes. In addition, the results strengthen the proposition that LEPRE1 should be the first gene analyzed in mutation detection studies in patients with recessive OI.

Analysis of FKBP10, SERPINH1, and SERPINF1 genes in patients with osteogenesis imperfecta

“…In a similar study, our group also analyzed LEPRE1, CRTAP, and PPIB genes and the results have already been published (Barbirato et al, 2015).…”

“…This study was approved by the Research Ethics Committee of the HINSG and informed consent was obtained from all participants (Barbirato et al, 2015).…”

“…The PCR products were screened for mutations by single-stranded conformation polymorphism (SSCP) on 5 and 7% polyacrylamide, 5% glycerol gels and on 6% glycerol mutation detection enhancement gels (Cambrex Bio Science Rockland, Inc.) (Orita et al, 1989;Spinardi et al, 1991). Fragments showing abnormal migration patterns were sequenced to detect the variation in the patients' DNA sequences compared with the National Center for Biotechnology Information (NCBI) reference sequences NG_012052.1, NG_015860.1, and NG_028180.1 (for SERPINH1, FKBP10, and SERPINF1, respectively), and with mutations described by Dalgleish (1998) in the Human Collagen Mutation Database (Barbirato et al, 2015).…”

Osteogenesis imperfecta in Brazilian patients

“…All participants gave informed consent to participate in this study. Fifteen patients previously described by our group (Barbirato et al , 2009, 2015, 2016; Moraes et al , 2012) were re-analyzed in this study.…”

“…Fragments with abnormal patterns on SSCP gels were analyzed after silver staining, and Sanger sequencing was performed in an ABI PRISM® 3100 Genetic Analyzer (Applied Biosystems, USA). The primers used for the COL1A1 gene were previously described by Körkkö et al (1998); those used for P3H1 , CRTAP and PPIB were reported by Barbirato et al (2015). The primers for COL1A2 , SERPINF1 , SERPINH1 , FKBP10, WNT1 and IFITM5 are described in the -.…”