LEPRE1

Autosomal recessive osteogenesis imperfecta (OI) accounts for 10% of all OI cases, and, currently, mutations in 10 genes (CRTAP, LEPRE1, PPIB, SERPINH1, FKBP10, SERPINF1, SP7, BMP1, TMEM38B, and WNT1) are known to be responsible for this form of the disease. PEDF is a secreted glycoprotein of the serpin superfamily that maintains bone homeostasis and regulates osteoid mineralization, and it is encoded by SERPINF1, currently associated with OI type VI (MIM 172860). Here, we report a consanguineous Brazilian family in which multiple individuals from at least 4 generations are affected with a severe form of OI, and we also report an unrelated individual from the same small city in Brazil with a similar but more severe phenotype...

Metabolic bone disorders in children frequently are heritable, but the expanding number of genes associated with these conditions makes it difficult to perform molecular diagnosis. In the present study, we therefore evaluated a semiconductor (SC)-based sequencing system for this purpose. A total of 65 DNA samples were analyzed comprising 24 samples from patients with 27 known pathogenic mutations, 6 samples from patients with prior negative Sanger sequencing, and 35 consecutive samples from patients with suspected heritable metabolic bone disorders who had not had prior molecular diagnosis...

OBJECTIVE: Literature review of new genes related to osteogenesis imperfecta (OI) and update of its classification. SOURCES: Literature review in the PubMed and OMIM databases, followed by selection of relevant references. SUMMARY OF THE FINDINGS: In 1979, Sillence et al. developed a classification of OI subtypes based on clinical features and disease severity: OI type I, mild, common, with blue sclera; OI type II, perinatal lethal form; OI type III, severe and progressively deforming, with normal sclera; and OI type IV, moderate severity with normal sclera...

Osteogenesis imperfecta (OI) is a hereditary bone disease characterized by decreased bone density and multiple fractures, usually inherited in an autosomal dominant manner. Several gene encoding proteins related to collagen metabolism have been described in some cases of autosomal recessive OI (including CRTAP, LEPRE1, PPIB, FKBP65, SERPINF1, BMP1, WNT1, FKBP10). Recently, TMEM38B, a gene that encodes TRIC-B, a monovalent cation-specific channel involved in calcium flux from intracellular stores and in cell differentiation, has been associated with autosomal recessive OI...

Biallelic mutations in LEPRE1 result in recessively inherited forms of osteogenesis imperfecta (OI) that are often lethal in the perinatal period. A mutation (c.1080+1G>T, IVS5+1G>T) in African Americans has a carrier frequency of about 1/240. The mutant allele originated in West Africa in tribes of Ghana and Nigeria where the carrier frequencies are 2% and 5%. By examining 200 samples from an African-derived population in Tobago and reviewing hospital neonatal death records, we determined that the carrier frequency of c...

Mutations in the genes encoding cartilage associated protein (CRTAP) and prolyl 3-hydroxylase 1 (P3H1 encoded by LEPRE1) were the first identified causes of recessive Osteogenesis Imperfecta (OI). These proteins, together with cyclophilin B (encoded by PPIB), form a complex that 3-hydroxylates a single proline residue on the α1(I) chain (Pro986) and has cis/trans isomerase (PPIase) activity essential for proper collagen folding. Recent data suggest that prolyl 3-hydroxylation of Pro986 is not required for the structural stability of collagen; however, the absence of this post-translational modification may disrupt protein-protein interactions integral for proper collagen folding and lead to collagen over-modification...

Members of the Leprecan family of proteins include enzymes, prolyl 3-hydroxylase 1 (P3h1), P3h2, and P3h3, and nonenzymatic proteins, Crtap and Sc65. Mutations in CRTAP and LEPRE1 (encoding P3H1) have been associated with human disease such as recessive osteogenesis imperfecta; however, the function of Sc65, which is closely related and highly homologous to Crtap, is unknown. Sc65 has been described as a synaptonemal complex protein, a nucleolar protein, and a cytoplasmic adapter protein. In light of its high sequence similarity with Crtap, an endoplasmic reticulum (ER)-associated protein, and the importance of post-translational modifications such as collagen prolyl 3-hydroxylation in bone metabolism, we hypothesized that Sc65 was an ER-resident protein that would have an important role in bone homeostasis...

Olfactory ensheathing cells (OECs) have neuro-restorative properties in animal models for spinal cord injury, stroke, and amyotrophic lateral sclerosis. Here we used a multistep screening approach to discover genes specifically contributing to the regeneration-promoting properties of OECs. Microarray screening of the injured olfactory pathway and of cultured OECs identified 102 genes that were subsequently functionally characterized in cocultures of OECs and primary dorsal root ganglion (DRG) neurons. Selective siRNA-mediated knockdown of 16 genes in OECs (ADAMTS1, BM385941, FZD1, GFRA1, LEPRE1, NCAM1, NID2, NRP1, MSLN, RND1, S100A9, SCARB2, SERPINI1, SERPINF1, TGFB2, and VAV1) significantly reduced outgrowth of cocultured DRG neurons, indicating that endogenous expression of these genes in OECs supports neurite extension of DRG neurons...

Autosomal recessive osteogenesis imperfecta (AR-OI) is an inherited condition which in recent years has been shown with increasing genetic and clinical heterogeneity. In this article, we performed clinical assessment and sought mutations in patients from 10 unrelated families with AR-OI, one of whom was presented with the additional features of Bruck syndrome (BS). Pathogenic changes were identified in five different genes: three families had mutations in FKBP10, three in SERPINF1, two in LEPRE1, one in CRTAP, and one in PPIB...

Until 2006 the only mutations known to cause osteogenesis imperfecta (OI) were in the two genes coding for type I collagen chains. These dominant mutations affecting the expression or primary sequence of collagen α1(I) and α2(I) chains account for over 90% of OI cases. Since then a growing list of mutant genes causing the 5-10% of recessive cases has rapidly emerged. They include CRTAP, LEPRE1, and PPIB, which encode three proteins forming the prolyl 3-hydroxylase complex; PLOD2 and FKBP10, which encode, respectively, lysyl hydroxylase 2 and a foldase required for its activity in forming mature cross-links in bone collagen; SERPINH1, which encodes the collagen chaperone HSP47; SERPINF1, which encodes pigment epithelium-derived factor required for osteoid mineralization; and BMP1, which encodes the type I procollagen C-propeptidase...

Osteogenesis imperfecta is a rare connective tissue disorder characterized by bone fragility and low bone density. Most cases are caused by an autosomal dominant mutation in either COL1A1 or COL1A2 gene encoding type I collagen. However, autosomal recessive forms have been identified. We present a patient with severe respiratory distress due to osteogenesis imperfecta simulating type II, born to a non-consanguineous couple with mixed African-American and African-Hispanic ethnicity. Cultured skin fibroblasts demonstrated compound heterozygosity for mutations in the LEPRE1 gene encoding prolyl 3-hydroxylase 1 confirming the diagnosis of autosomal recessive osteogenesis imperfecta type VIII, perinatal lethal type...

Prolyl 3-hydroxylase1 (P3H1) is a collagen modifying enzyme which hydroxylates certain prolines in the Xaa position of conventional GlyXaaYaa triple helical sequence. Recent investigations have revealed that mutations in the LEPRE1 (gene encoding for P3H1) cause severe osteogenesis imperfecta (OI) in humans. Similarly LEPRE1 knockout mice display an OI-like phenotype. Significant hearing loss is a common problem for people with osteogenesis imperfecta. Here we report that hearing of the P3H1 null mice is substantially affected...

BACKGROUND: Prolyl hydroxylation is a post-translational modification that affects the structure, stability and function of proteins including collagen by catalysing hydroxylation of proline to hydroxyproline through action of collagen prolyl hydroxylases3 (C-P3H) and 4 (C-P4H). Three C-P3Hs (nomenclature was amended according to approval by the HGNC symbols and names at https://www.genenames.org/ and Entrez database at https://www.ncbi.nlm.nih.gov/gene) leucineproline-enriched proteoglycan (leprecan) 1 (Lepre1), leprecan-like 1 (Leprel1), leprecan-like 2 (Leprel2) and two paralogs Cartilage-Related Protein (CRTAP) and leprecan-like 4 (Leprel4) are found in humans...

Growing evidence indicates that Rab GTPases, key regulators of intracellular transport in eukaryotic cells, play an important role in cancer. We analysed the deregulation at the transcriptional level of the genes encoding Rab proteins and Rab-interacting proteins in bladder cancer pathogenesis, distinguishing between the two main progression pathways so far identified in bladder cancer: the Ta pathway characterized by a high frequency of FGFR3 mutation and the carcinoma in situ pathway where no or infrequent FGFR3 mutations have been identified...

Prolyl 3-hydroxylase 1 (P3H1), encoded by the LEPRE1 gene, forms a molecular complex with cartilage-associated protein (CRTAP) and cyclophilin B (encoded by PPIB) in the endoplasmic reticulum (ER). This complex is responsible for one step in collagen post-translational modification, the prolyl 3-hydroxylation of specific proline residues, specifically α1(I) Pro986. P3H1 provides the enzymatic activity of the complex and has a Lys-Asp-Glu-Leu (KDEL) ER-retrieval sequence at the carboxyl terminus. Loss of function mutations in LEPRE1 lead to the Pro986 residue remaining unmodified and lead to slow folding and excessive helical post-translational modification of type I collagen, which is seen in both dominant and recessive osteogenesis imperfecta (OI)...

PURPOSE: Deficiency of prolyl 3-hydroxylase 1, encoded by LEPRE1, causes recessive osteogenesis imperfecta (OI). We previously identified a LEPRE1 mutation exclusively in African Americans and contemporary West Africans. We hypothesized that this allele originated in West Africa and was introduced to the Americas with the Atlantic slave trade. We aimed to determine the frequency of carriers for this mutation among African Americans and West Africans, and the mutation origin and age. METHODS: Genomic DNA was screened for the mutation using PCR and restriction digestion, and a custom TaqMan genomic single-nucleotide polymorphism assay...

Osteogenesis imperfecta (OI) comprises a group of inherited disorders characterized by bone fragility and increased susceptibility to fractures. Historically, the laboratory confirmation of the diagnosis OI rested on cultured dermal fibroblasts to identify decreased or abnormal production of abnormal type I (pro)collagen molecules, measured by gel electrophoresis. With the discovery of COL1A1 and COL1A2 gene variants as a cause of OI, sequence analysis of these genes was added to the diagnostic process. Nowadays, OI is known to be genetically heterogeneous...

Dominant inheritance of osteogenesis imperfecta (OI) is caused by mutations in COL1A1 or COL1A2, the genes that encode type I collagen, and CRTAP, LEPRE1, PPIB, FKBP10, SERPINH1, and SP7 mutations were recently detected in a minority of patients with autosomal recessive OI. However, these findings have been mostly restricted to Western populations. The proportion of mutations and the correlations between genotype and phenotype in Chinese patients with OI are completely unknown. In this study, mutation analyses were performed for COL1A1, COL1A2, CRTAP, and LEPRE1 in a cohort of 58 unrelated Chinese patients with OI; the relationship between collagen type I mutations and clinical features was examined...

Osteogenesis imperfecta (OI) is a heterogeneous group of inherited disorders of bone formation, resulting in low bone mass and an increased propensity to fracture. It exhibits a broad spectrum of clinical severity, ranging from multiple fractures in utero and perinatal death, to normal adult stature and low fracture incidence. Extra-skeletal features of OI include blue sclera, hearing loss, skin hyperlaxity, joint hyperextensibility, and dentinogenesis imperfecta. The proα1(I) and proα2(I) chains of collagen 1 are encoded by the COL1A1 and COL1A2 genes, respectively; quantitative or qualitative defects in type I collagen synthesis usually manifest as types of OI or some sub-types of EDS...

Recessive mutations in the cartilage-associated protein (CRTAP), leucine proline-enriched proteoglycan 1 (LEPRE1) and peptidyl prolyl cis-trans isomerase B (PPIB) genes result in phenotypes that range from lethal in the perinatal period to severe deforming osteogenesis imperfecta (OI). These genes encode CRTAP (encoded by CRTAP), prolyl 3-hydroxylase 1 (P3H1; encoded by LEPRE1) and cyclophilin B (CYPB; encoded by PPIB), which reside in the rough endoplasmic reticulum (RER) and can form a complex involved in prolyl 3-hydroxylation in type I procollagen...