Osteogenesis imperfecta (OI) is basically divided into four clinical types, I-IV. Type IV clearly represents a heterogeneous group of disorders. Here we describe two OI patients in the same family. They would typically be classified as having type IV, but are distinguishable from other OI type IV patients by the improving and resolving course of their disease. Mutation screening did not identify mutations affecting glycine codons or splice sites in the coding regions of the two collagen I genes. Genome-wide screening of DNA samples from the two homozygous patients identified one region of high concordance of homozygosity on chromosome 11 on the long arm (11q23.3-11q24.1).
2008 Wiley-Liss, Inc.