TY - JOUR T1 - A familial disorder of altered DNA-methylation JF - Journal of Medical Genetics JO - J Med Genet SP - 407 LP - 412 DO - 10.1136/jmedgenet-2013-102149 VL - 51 IS - 6 AU - Almuth Caliebe AU - Julia Richter AU - Ole Ammerpohl AU - Deniz Kanber AU - Jasmin Beygo AU - Susanne Bens AU - Andrea Haake AU - Eva Jüttner AU - Bernhard Korn AU - Deborah J G Mackay AU - José I Martin-Subero AU - Inga Nagel AU - Neil J Sebire AU - Larissa Seidmann AU - Inga Vater AU - Constantin Sylvius von Kaisenberg AU - I Karen Temple AU - Bernhard Horsthemke AU - Karin Buiting AU - Reiner Siebert Y1 - 2014/06/01 UR - http://jmg.bmj.com/content/51/6/407.abstract N2 - Background In a subset of imprinting disorders caused by epimutations, multiple imprinted loci are affected. Familial occurrence of multilocus imprinting disorders is rare. Purpose/objective We have investigated the clinical and molecular features of a familial DNA-methylation disorder. Methods Tissues of affected individuals and blood samples of family members were investigated by conventional and molecular karyotyping. Sanger sequencing and RT-PCR of imprinting-associated genes (NLRP2, NLRP7, ZFP57, KHDC3L, DNMT1o), exome sequencing and locus-specific, array-based and genome-wide technologies to determine DNA-methylation were performed. Results In three offspring of a healthy couple, we observed prenatal onset of severe growth retardation and dysmorphism associated with altered DNA-methylation at paternally and maternally imprinted loci. Array-based analyses in various tissues of the offspring identified the DNA-methylation of 2.1% of the genes in the genome to be recurrently altered. Despite significant enrichment of imprinted genes (OR 9.49), altered DNA-methylation predominately (90.2%) affected genes not known to be imprinted. Sequencing of genes known to cause comparable conditions and exome sequencing in affected individuals and their ancestors did not unambiguously point to a causative gene. Conclusions The family presented herein suggests the existence of a familial disorder of DNA-methylation affecting imprinted but also not imprinted gene loci potentially caused by a maternal effect mutation in a hitherto not identified gene. ER -