Oxytocin receptor gene methylation in male and female PTSD patients and trauma-exposed controls.

Oxytocin receptor gene (OXTR) DNA-methylation levels have been associated with trauma-exposure, mood- and anxiety disorders, and social processes relevant to posttraumatic stress disorder (PTSD). We hypothesized that OXTR methylation may play a role in the neurobiological underpinnings of PTSD. In the current study, we compared OXTR methylation between PTSD patients (n = 31, 14 females) and trauma-exposed controls (n = 36, 19 females). Additionally, the association between OXTR methylation and PTSD symptom severity and amygdala reactivity to an emotional faces task was assessed, as a neural hallmark of PTSD. DNA-methylation was investigated in the CpG island located at exon 3 of the OXTR, previously associated with OXTR expression. We observed a significant interaction between PTSD-status, sex and CpG-position on methylation levels. Post-hoc testing revealed that methylation levels at two specific CpG-sites were significantly higher in PTSD females compared to female trauma-exposed controls and PTSD males (CpGs Chr3:8809437, Chr3:8809413). No significant differences in methylation were observed between male PTSD patients and controls. Furthermore, within PTSD females, methylation in these CpG-sites was positively associated with anhedonia symptoms and with left amygdala responses to negative emotional faces, although this was no longer significant after stringent correction for multiple-comparisons. Though the modest size of the current sample is an important limitation, we are the first to report on OXTR methylation in PTSD, replicating previously observed (sex-specific) associations of OXTR methylation with other psychiatric disorders.

Genome-wide methylation profiling of Beckwith-Wiedemann syndrome patients without molecular confirmation after routine diagnostics.

Beckwith-Wiedemann syndrome (BWS) is caused due to the disturbance of imprinted genes at chromosome 11p15. The molecular confirmation of this syndrome is possible in approximately 85% of the cases, whereas in the remaining 15% of the cases, the underlying defect remains unclear. The goal of our research was to identify new epigenetic loci related to BWS. We studied a group of 25 patients clinically diagnosed with BWS but without molecular conformation after DNA diagnostics and performed a whole genome methylation analysis using the HumanMethylation450 Array (Illumina).We found hypermethylation throughout the methylome in two BWS patients. The hypermethylated sites in these patients overlapped and included both non-imprinted and imprinted regions. This finding was not previously described in any BWS-diagnosed patient.Furthermore, one BWS patient exhibited aberrant methylation in four maternally methylated regions-IGF1R, NHP2L1, L3MBTL, and ZDBF2-that overlapped with the differentially methylated regions found in BWS patients with multi-locus imprinting disturbance (MLID). This finding suggests that the BWS phenotype can result from MLID without detectable methylation defects in the primarily disease-associated loci (11p15). Another patient manifested small but significant aberrant methylation in disease-associated loci at 11p near H19, possibly confirming the diagnosis in this patient.

Changes in mRNA expression profile underlie phenotypic adaptations in creatine kinase-deficient muscles.

We have studied the mechanisms that regulate the remodeling of the glycolytic, mitochondrial and structural network of muscles of creatine kinase M (M-CK)/sarcomeric mitochondrial creatine kinase (ScCKmit) knockout mice by comparison of wild-type and mutant mRNA profiles on cDNA arrays. The magnitudes of changes in mRNA levels were most prominent in M-CK/ScCKmit (CK(-/-)) double mutants but did never exceed those of previously observed changes in protein level for any protein examined. In gastrocnemius of CK(-/-) mice we measured a 2.5-fold increase in mRNA level for mitochondrial encoded cytochrome c oxidase (COX)-III which corresponds to the increase in protein content. The level of the nuclear encoded mRNAs for COX-IV, H(+)-ATP synthase-C, adenine nucleotide translocator-1 and insulin-regulatable glucose transporter-4 showed a 1.5-fold increase, also in agreement with protein data. In contrast, no concomitant up-regulation in mRNA and protein content was detected for the mitochondrial inorganic phosphate-carrier, voltage-dependent anion channel and certain glycolytic enzymes. Our results reveal that regulation of transcript level plays an important role, but it is not the only principle involved in the remodeling of mitochondrial and cytosolic design of CK(-/-) muscles.

Dihydropyrimidine dehydrogenase deficiency caused by a novel genomic deletion c.505_513del of DPYD.

Dihydropyrimidine dehydrogenase (DPD) deficiency is an autosomal recessive disorder of the pyrimidine degradation pathway. In a patient presenting with convulsions, psychomotor retardation and Reye like syndrome, strongly elevated levels of uracil and thymine were detected in urine. No DPD activity could be detected in peripheral blood mononuclear cells. Analysis of the gene encoding DPD (DPYD) showed that the patient was homozygous for a novel c.505_513del (p.169_171del) mutation in exon 6 of DPYD.