ICCBH2013 Poster Presentations (1) (201 abstracts)
1Department of Life and Reproduction Sciences and Pediatric Clinic, University of Verona, Verona, Italy; 2Complex of Operative Unit of Pediatric, A.U.L.S.S. 21 Legnago, Verona, Italy.
Background: Osteogenesis imperfecta (OI) is a group of hereditary disorders characterized by bone fragility and osteopaenia, with a broad spectrum of clinical severity. The majority of cases are dominantly inherited and due to mutations in type I collagen genes, whereas recessive forms are less frequent and attributable to mutations in different genes involved in collagen I post translational modifications and folding (prolyl-3-hydroxylase complex, SERPINH1, FKBP10).
Case report: We report the case of an Italian 14-year-old boy with an initially mild and then increasingly moderatesevere form of osteogenesis imperfecta. He revealed wild-type sequence in COL1A1, COL1A2, CRTAP, LEPRE1 and SERPINH1 genes, respectively. Biochemical analysis, moreover, of dermal fibroblasts type I collagen and procollagen chains showed normal migration and amounts. Subsequent sequencing of FKBP10 gene revealed instead a novel homozygous splicing mutation in intron 8 (c.1399+1G>A), which results in aberrant mRNA processing and consequent lack of FKBP65 chaperone.
The probands clinical features seem milder than those described in other FKBP10 cases, resembling OI type I at infancy, with slight joint laxity but no arthrogryposis. The histomorphometric analysis confirms an osteomalacic aspect meanwhile a qualitative evaluation shows loss of the normal orientation of the lamellae, with mixed fish-scale and mesh like patterns.