Abstract
The aim of the present study was to characterize the clinical manifestations and identify the mutations of Serpin family F member 1 (SERPINF1) and FK506 binding protein 10 (FKBP10) genes in Chinese patients with osteogenesis imperfecta (OI). Using whole‑exome sequencing in the first and third probands, a novel mutation was identified in SERPINF1 and a novel compound heterozygous mutation was revealed in FKBP10. Using Sanger sequencing, an additional novel mutation in SERPINF1 was identified in a proband of family 2. In family 1, the proband presented with a novel homozygous missense mutation of the SERPINF1 gene, c.1067T>A (V356E). In family 2, the proband had a novel homozygous deletion mutation of the SERPINF1 gene, c.283+473_643+104del (p.Ala96_Gly215del). Serum pigment‑epithelium‑derived factor concentration was not detected in probands with OI type VI. For both families, the proband's father was demonstrated to have a heterozygous mutation of SERPINF1, whereas no mutations was detected in the probands' mothers. An assessment of allelic copy numbers revealed a deletion of SERPINF1 in the mother of family 1. The results of the present study demonstrate that patients may have mild symptoms of OI with a large fragment deletion in the SERPINF1 gene. Thus, the phenotype of Chinese patients with type VI OI is milder than that of Caucasian and Korean patients. In family 3, the proband displayed a novel compound heterozygous mutation in FKBP10, c.813_814delGA (p.Glu271AspfsX101) and c.831delC (p.Gly278AlafsX20), and did not have Bruck syndrome. Codon 831 of the FKBP10 gene may represent a mutation hotspot for human OI. These results extend both the phenotypic and the genotypic contents of OI patients with SERPINF1 or FKBP10 mutations.