CASyM winter school of Systems Medicine took place between March 29th and April 1st 2017 in Ljubljana, Slovenia and is entitled »The 3rd SysBioMed hands-on tutorial: Systems Medicine Approaches in Personalized Medicine«
Genetic testing of osteogenesis imperfecta related genes in Slovene patients with next generation sequencing
Sara Bertok1,Darja Šmigoc Schweiger1,Maruša Debeljak2,Jernej Kovač2,Tadej Battelino1,3,Katarina Trebušak Podkrajšek2,3
1Department of Paediatric Endocrinology, Diabetes and Metabolic Diseases, University Children’s Hospital, University Medical Centre Ljubljana, Ljubljana, Slovenia,2Unit of Special Laboratory Diagnostics, University Children’s Hospital, University Medical Centre Ljubljana, Ljubljana, Slovenia,3Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
Introduction. Osteogenesis imeperfecta (OI) is characterised by bone fragility frequently associated with blue/gray discoloration of the sclera and dentinogenesis imperfecta. The disease is classified in several types according to the severity of the bone fragility or genetic aetiology. OI is genetically heterogeneous disease with dominant mutations in COL1A1 and COL1A2 being the most common genetic cause. Molecular genetic testing of OI is important, as it can prompt the treatment. Materials and Methods. Fifteen subjects (3 males, 12 females) aged between 1 month and 18 years were evaluated at a tertiary paediatric outpatient clinic due to the bone fragility and referred to genetic testing with next generation sequencing (NGS). Patients 7 and 8 were sisters. Fourteen patients had clinically mild OI, one had clinically severe OI. All had blue sclera and none had additional hearing loss or dentinogenesis imperfecta. We performed targeted NGS with TruSightOne Sequencing Panel on the MiSeq platform (Illumina, USA) followed by interpretation of variants in the selected OI associated genes (ALPL, BMP1, COL1A1, COL1A2, CRTAP, FKBP10, IFITM5, LEPRE1, LRP5, PLOD2, PPIB, SERPINF1, SERPINH1, SP7) and subsequent Sanger sequencing confirmation. Novel variants were evaluated with in silico prediction tools Mutation Taster and CADD. Results. Eleven different mutations in two genes (COL1A1 and COL1A2) were detected in 11 patients (73% success rate) all in heterozygous state. Among them, five variants predicted to be causative were not previously reported in OI patients, namely COL1A1 variants c.1853delC (p.Ala618ValfsTer148), c.740C>T (p.Pro247Leu), 2606delG (p.Gly869ValfsTer239), c.3936delG (p.Trp1312CysfsTer19) and COL1A2 variant c.1704_1705insAAA (p.Gly568_Lys569ins Lys). Conclusion. NGS enables fast and reliable identification of causal mutations in several genes related to OI simultaneously. Presented subject group had mutations in genes commonly associated with OI, where each patients had his own private mutation and 5 of them have previously not been described in OI patients.
2006 - University of Ljubljana, Faculty of Medicine, Center for Functional Genomics and Bio-chips.