Deniz Torun

Molecular etiology of arthrogryposis in multiple families of mostly Turkish origin

BACKGROUND Arthrogryposis, defined as congenital joint contractures in 2 or more body areas, is a clinical sign rather than a specific disease diagnosis. To date, more than 400 different disorders have been described that present with arthrogryposis, and variants of more than 220 genes have been associated with these disorders; however, the underlying molecular etiology remains unknown in the considerable majority of these cases. METHODS We performed whole exome sequencing (WES) of 52 patients with clinical presentation of arthrogryposis from 48 different families. RESULTS Affected individuals from 17 families (35.4%) had variants in known arthrogryposis-associated genes, including homozygous variants of cholinergic γ nicotinic receptor (CHRNG, 6 subjects) and endothelin converting enzyme-like 1 (ECEL1, 4 subjects). Deleterious variants in candidate arthrogryposis-causing genes (fibrillin 3 [FBN3], myosin IXA [MYO9A], and pleckstrin and Sec7 domain containing 3 [PSD3]) were identified in 3 families (6.2%). Moreover, in 8 families with a homozygous mutation in an arthrogryposis-associated gene, we identified a second locus with either a homozygous or compound heterozygous variant in a candidate gene (myosin binding protein C, fast type [MYBPC2] and vacuolar protein sorting 8 [VPS8], 2 families, 4.2%) or in another disease-associated genes (6 families, 12.5%), indicating a potential mutational burden contributing to disease expression. CONCLUSION In 58.3% of families, the arthrogryposis manifestation could be explained by a molecular diagnosis; however, the molecular etiology in subjects from 20 families remained unsolved by WES. Only 5 of these 20 unrelated subjects had a clinical presentation consistent with amyoplasia; a phenotype not thought to be of genetic origin. Our results indicate that increased use of genome-wide technologies will provide opportunities to better understand genetic models for diseases and molecular mechanisms of genetically heterogeneous disorders, such as arthrogryposis. FUNDING This work was supported in part by US National Human Genome Research Institute (NHGRI)/National Heart, Lung, and Blood Institute (NHLBI) grant U54HG006542 to the Baylor-Hopkins Center for Mendelian Genomics, and US National Institute of Neurological Disorders and Stroke (NINDS) grant R01NS058529 to J.R. Lupski.

The phenotypic and molecular genetic spectrum of Alström syndrome in 44 Turkish kindreds and a literature review of Alström syndrome in Turkey.

Correction to: Journal of Human Genetics (2015) 60, 1–9; doi:10.1038/jhg.2014.85; published online 9 October 2014 Since the advance online publication of this article, the authors of the above paper have noticed errors in the list of authors and affiliations. Article with correct authors informationnow appears in this issue.

Mitochondrial complex I and III gene mRNA levels in schizophrenia, and their relationship with clinical features.

BackgroundThe etiology of schizophrenia is not precisely known; however, mitochondrial function and cerebral energy metabolism abnormalities were determined to be possible factors associated with the etiology of schizophrenia. Impaired mitochondrial function negatively affects neuronal plasticity, and can cause cognitive deficits and behavioral abnormalities observed during the clinical course of schizophrenia. The present study aimed to investigate the relationship between the clinical features of schizophrenia, and mitochondrial complex activation, based on measurement of mRNA levels in the NDUFV1, NDUFV2, NDUFS1, and UQCR10 genes involved in the peripheral mitochondrial complex.MethodsThe study included 138 schizophrenia patients and 42 healthy controls. The schizophrenia group was divided into a chronic schizophrenia subgroup (n = 84) and a first-episode schizophrenia subgroup (n = 54). The symptoms profile and severity of disorder were evaluated using the Scale for the Assessment of Negative Symptoms (SANS), Scale for the Assessment of Positive Symptoms (SAPS), and Brief Psychiatric Rating Scale (BPRS).ResultsThe level of mRNA expression of NDUFV1, NDUFV2, and NDUFS1 was significantly higher in the schizophrenia group than in the control group. The mRNA level of NDUFV2 was positively correlated with BPRS and SAPS scores in the first-episode schizophrenia subgroup.ConclusionThe findings showed that there was a positive correlation between gene mRNA levels and psychotic symptomatology, especially positive symptoms. Our results suggest that mRNA levels of the NDUFV1, NUDFV2, and NDUFS1 genes of complex I of the mitochondrial electron transport chain might become a possible peripheral marker for the diagnosis of schizophrenia.

The rate of MEFV gene mutations in hematolymphoid neoplasms

The aim of this study was to determine the rate of MEFV gene mutations, the gene responsible for familial Mediterranean fever (FMF), in patients with hematolymphoid neoplasm. The rate of the five most common MEFV gene mutations (M694V, M680I, V726A, M694I and E148Q) was determined in 46 patients with hematolymphoid neoplasm. We found a high frequency of carriers in patients with multiple myeloma (60%) and acute lymphocytic leukaemia (33.3%), whereas patients with chronic lymphocytic leukaemia (9%) and non‐Hodgkin lymphoma (5%) had a low mutation carrier rate. There is no MEFV gene mutation in patients with Hodgkin lymphoma. Furthermore, the statistically significant predominance of strong heterozygous mutations such as M694V and M680I in patients with hematolymphoid neoplasm; none had own and/or family history compatible with FMF, is interesting. In conclusion, we found a high frequency of carriers for MEFV gene in patients with multiple myeloma and acute lymphocytic leukaemia. The data of our study may provide some new insights in understanding of individual genetic differences in susceptibility to these neoplasms.

High frequency of MEFV gene mutations in patients with myeloid neoplasm

We aimed to investigate the rate of MEFV, the gene mutated in familial Mediterranean fever, mutations in patients with myeloid neoplasm and to determine if known mutations of MEFV cause a tendency for myeloid neoplasms. The frequency of the five most common MEFV gene mutations (M694V, M680I, V726A, E148Q and M694I) was determined in 26 patients with myeloid neoplasm. We identified 1 homozygous (E148Q/E148Q), 1 compound heterozygous (M694V/E148Q) and 5 heterozygous MEFV gene mutations; none had their own and/or family history compatible with familial Mediterranean fever. The mean overall mutation rate was 0.269. We found a high frequency of carriers in patients with myelodysplastic syndrome (66.6%), polycythemia vera (33.3%) and acute myeloid leukemia (28.6%). However, there was no MEFV gene mutation in patients with chronic myeloid leukemia. In conclusion, this study reports for the first time a possibly high prevalence of MEFV gene mutations in patients with myeloid neoplasm, especially myelodysplastic syndrome, polycythemia vera and acute myeloid leukemia. Our findings could open new perspectives for MEFV gene mutations in myeloid neoplasms and its association with tumor promotion. Further research is needed to determine the actual role of MEFV gene mutations in these malignancies.

Mitochondrial complex I and III mRNA levels in bipolar disorder

BACKGROUND Studies that have focused on the mitochondrial electron transport chain indicate that bipolar disorder (BD) is associated with pathology in mitochondrial function. These pathological processes occur in the brain circuits that regulate affective functions, emotions, and motor behaviors. The present study aimed to determine the relationship between mitochondrial complex dysfunction and BD. METHODS The BD group included 32 male patients diagnosed with first-episode manic BD. The control group included 35 sociodemographically matched healthy males. Messenger ribonucleic acid (mRNA) was isolated from peripheral blood samples obtained from the patients and control group, and the mRNA levels of the NDUFV1, NDUFV2, and NDUFS1 genes of mitochondrial complex I and the UQCR10 gene of mitochondrial complex III were investigated. RESULTS Significant differences were identified in complex I gene mRNA levels between the BD group (n = 32) and the control group (n = 35) for the following genes: NDUFV1 (P = 0.01), NDUFV2 (P < 0.01), and NDUFS1 (P = 0.02). The UQCR10 gene (complex III) mRNA level did not differ between the groups (P = 0.1). The mRNA levels of the four genes studied were lower at the 3-month follow-up; however, these differences were not significant (P > 0.05). LIMITATIONS All of the BD patients were in manic episodes; thus, we were unable to separately compare these levels with those during depressive and euthymic episodes. CONCLUSIONS The mRNA levels of all of the genes representing the subunits of mitochondrial complex I (NDUFV1, NDUFV2, and NDUFS1) were significantly higher in the present studys BD patients during manic episodes than in the controls. With the data obtained from further research, biomarkers that could be used for the diagnosis and follow-up of neuropsychiatric disorders may be discovered.

Effects of "iRoot BP" and "white mineral trioxide aggregate" on cell viability and the expression of genes associated with mineralization

AIM To evaluate the cytotoxicity and mineralization effects of iRoot BP in human dental pulp cells (hDPCs) and to compare them with those of white mineral trioxide aggregate (WMTA). METHODOLOGY hDPCs were exposed to prepared dilutions (1 : 1-1 : 10) of the test materials. Cell viability was evaluated using the XTT assay after incubation periods of 24, 48 or 72 h. The expression of mineralization-related genes (bone morphogenic protein, osteonectin, bone sialoprotein, osteopontin, dentine sialophosphoprotein and collagen type 1) and heme oxygenase 1 was measured by quantitative real-time polymerase chain reaction (qRT-PCR) at 24 and 72 h. Statistical differences between test materials were analysed with the Mann-Whitney test. RESULTS The 1 : 1 and 1 : 2 dilutions of iRoot BP were associated with higher cell viability after 24 h (P < 0.05). Only the 1 : 1 dilution of iRoot BP had higher cell viability after 48 h (P < 0.05), and there was no difference between iRoot BP and WMTA after 72 h (P > 0.05). Although somewhat variable, according to the gene expression results, iRoot BP had a mineralization potential similar to that of WMTA. WMTA revealed a higher heme oxygenase 1 (HO-1) mRNA level than iRoot BP (P < 0.001). CONCLUSIONS iRoot BP and WMTA were biocompatible and facilitated odontoblastic differentiation of hDPCs.

Gorlin-Chaudhry-Moss syndrome revisited: expanding the phenotype.

Gorlin–Chaudhry–Moss syndrome (OMIM 233500) is a rare congenital malformation syndrome with the cardinal manifestations of craniofacial dysostosis, hypertrichosis, underdeveloped genitalia, ocular, and dental anomalies. Since 1960, only six affected individuals have been reported. We report a 4‐year and 6‐month‐old female patient with this phenotype and review the clinical presentation of all patients known so far. Previously unreported malformations of the extremities, larynx, and nose are also described, expanding the phenotype of this rare syndrome. Array‐CGH analysis did not show pathological deletions or duplications.

Hypoxia inhibits mineralization ability of human dental pulp cells treated with TEGDMA but increases cell survival in accordance with the culture time.

OBJECTIVE To evaluate the cytotoxicity and mineralization effects of TEGDMA in human dental pulp cells (hDPCs) under hypoxic and normoxic culture conditions. DESIGN Cell viability was evaluated using XTT assay after incubation periods of 24, 48, or 72h. The expression of mineralization-related genes (osteonectin, osteopontin, dentin sialophosphoprotein, collagen type 1) and heme oxygenase 1 (HO-1) was assessed by quantitative real-time polymerase chain reaction at 24 and 72h. RESULTS In XTT assay, viability was higher in 0.3, 1, 2, 4, and 5mM groups in the presence of 21% O2 after 24h (p<0.05). Additionally, while 0.3, 1, 2mM groups had higher cell viability in the presence of 21% O2 after 48h (p<0.05), in 3mM groups cell viability was higher under 3% O2 than 21% O2 after both 24 and 48h (p<0.05). 1-3mM groups had higher cell viability under 3% O2 after 72h (p<0.05). There was no difference between 4 and 5mM groups with regards to cell viability after 48 or 72h (p>0.05). In the gene expression study, TEGDMA-treated hDPCs showed lower mineralization potential in the presence of 3% than with 21% O2 (p<0.05). hDPCs revealed higher HO 1 expression in 0.3 and 1mM groups under hypoxic than under normoxic conditions after a 72-h time period (p<0.001). CONCLUSIONS Hypoxic conditions increased cell survival in accordance with the culture period but inhibited the odontoblastic differentiation of hDPCs treated with TEGDMA.

Methylation of SOCS3 in Myeloproliferative Neoplasms and Secondary Erythrocytosis/Thrombocythemia

Objective: Myeloproliferative neoplasms (MPNs) like essential thrombocythemia (ET), polycythemia vera (PV), and primary myelofibrosis (PMF) are acquired clonal hematopoietic stem cell disorders and originate from a multipotent hematopoietic stem cell. The SOCS1 and SOCS3 genes are negative regulators of the JAK/STAT signal pathway. In this study we investigate the promoter methylation of these genes in the pathogenesis of MPNs and secondary erythrocytosis/thrombocythemia. Materials and Methods: Promoter methylation of SOCS1 and SOCS3 genes was analyzed with methylation-specific PCR. PCR products were analyzed by agarose gel electrophoresis. Results: No disease-specific CpG island methylation of SOCS1 was observed. Hypermethylation of the SOCS3 promoter was identified in 5 out of 19 (26.3%) PV cases, 2 out of 21 (9.5%) ET cases, 1 out of 5 (20%) PMF cases, and 9 out of 42 (21.4%) cases of secondary erythrocytosis/thrombocythemia. Conclusion: The results revealed that promoter methylation of the SOCS3 gene suggests a possible role for SOCS3 methylation in the pathogenesis of MPNs and secondary erythrocytosis/thrombocythemia. Conflict of interest:None declared.