Clinical and Functional Characterization of a Patient Carrying a Compound Heterozygous Pericentrin Mutation and a Heterozygous IGF1 Receptor Mutation

Intrauterine and postnatal longitudinal growth is controlled by a strong genetic component that regulates a complex network of endocrine factors integrating them with cellular proliferation, differentiation and apoptotic processes in target tissues, particularly the growth centers of the long bones. Here we report on a patient born small for gestational age (SGA) with severe, proportionate postnatal growth retardation, discreet signs of skeletal dysplasia, microcephaly and moyamoya disease. Initial genetic evaluation revealed a novel heterozygous IGF1R p.Leu1361Arg mutation affecting a highly conserved residue with the insulin-like growth factor type 1 receptor suggestive for a disturbance within the somatotropic axis. However, because the mutation did not co-segregate with the phenotype and functional characterization did not reveal an obvious impairment of the ligand depending major IGF1R signaling capabilities a second-site mutation was assumed. Mutational screening of components of the somatotropic axis, constituents of the IGF signaling system and factors involved in cellular proliferation, which are described or suggested to provoke syndromic dwarfism phenotypes, was performed. Two compound heterozygous PCNT mutations (p.[Arg585X];[Glu1774X]) were identified leading to the specification of the diagnosis to MOPD II. These investigations underline the need for careful assessment of all available information to derive a firm diagnosis from a sequence aberration

Guidance to bone morbidity in children and adolescents undergoing allogeneic hematopoietic stem cell transplantation

Abstract Allogeneic hematopoietic stem cell transplantation (HSCT) is widely performed in children and adolescents with hematologic diseases, including very high-risk leukemia. With increasing success and survival rates, the long-term sequelae of HSCT have become important. Here, we provide guidance to the prevention and treatment of the most common bone morbidities—osteoporosis and osteonecrosis—emerging in the context of HSCT in children and adolescents. We give an overview on definitions, symptoms, and diagnostics and propose an algorithm for clinical practice based on discussions within the International Berlin Frankfurt Münster (BFM) Stem Cell Transplantation Committee and the Pediatric Disease Working Party of the European Society for Blood and Marrow Transplantation, our expert knowledge, and a literature review