Hamza Okur

The effect of depression, BDNF gene val66met polymorphism and gender on serum BDNF levels

OBJECTIVE To determine the effect of BDNF gene val66met polymorphism on serum BDNF levels in drug-free patients with major depressive disorder (MDD) and healthy subjects, that differ by gender. METHODS Sixty-six drug-free patients (19 males+47 females) with non-psychotic MDD and fifty-six healthy controls (18 males+38 females) were recruited. Three-way ANOVA was employed to analyze the effect of mental health status, met-carriage and gender on Hamilton Depression Rating Scale (HDRS) scores and serum BDNF levels, by using the MIXED Procedure (SAS). RESULTS Patients had a lower serum BDNF level than healthy subjects (22.47 vs. 27.49; p<0.0001). Met-carrier patients had a higher HDRS score than Val homozygotes (25.99 vs. 22.99, p<0.02). Serum BDNF level for met-carrier subjects (patients+controls) was lower than Val homozygote subjects (23.08 vs. 26.87; p<0.002). However, there were no effects of two-way interactions of met-carriage and mental health status on HDRS scores and serum BDNF levels. There was no gender effect on HDRS scores in the patients. Overall, male subjects (patients+controls) had a higher serum BDNF level than female subjects (26.87 vs. 23.08; p<0.002). However, there were no effects of two-way interactions of gender with mental health status and met-carriage on serum BDNF levels. CONCLUSIONS We replicated the previous findings of lower serum BDNF levels during depression and in females. In addition, we found that met-carriage had an effect in reducing serum BDNF levels, regardless of gender and depression. Further animal and human studies with a larger sample size should investigate whether BDNF val66met polymorphism could alter brain and serum BDNF levels.

ALX4 dysfunction disrupts craniofacial and epidermal development

Genetic control of craniofacial morphogenesis requires a complex interaction of numerous genes encoding factors essential for patterning and differentiation. We present two Turkish families with a new autosomal recessive frontofacial dysostosis syndrome characterized by total alopecia, a large skull defect, coronal craniosynostosis, hypertelorism, severely depressed nasal bridge and ridge, bifid nasal tip, hypogonadism, callosal body agenesis and mental retardation. Using homozygosity mapping, we mapped the entity to chromosome 11p11.2-q12.3 and subsequently identified a homozygous c.793C-->T nonsense mutation in the human ortholog of the mouse aristaless-like homeobox 4 (ALX4) gene. This mutation is predicted to result in a premature stop codon (p.R265X) of ALX4 truncating 146 amino acids of the protein including a part of the highly conserved homeodomain and the C-terminal paired tail domain. Although the RNA is stable and not degraded by nonsense-mediated RNA decay, the mutant protein is likely to be non-functional. In a skin biopsy of an affected individual, we observed a hypomorphic interfollicular epidermis with reduced suprabasal layers associated with impaired interfollicular epidermal differentiation. Hair follicle-like structures were present but showed altered differentiation. Our data indicate that ALX4 plays a critical role both in craniofacial development as in skin and hair follicle development in human.

Smaller Hippocampus Volume Is Associated with Short Variant of 5-HTTLPR Polymorphism in Medication-Free Major Depressive Disorder Patients

Aim: Serotonin is known for its importance in the pathophysiology of major depressive disorder. Although the hippocampus is one of the key regions in which neurogenesis occurs, and serotonin plays an important role in neurogenesis, results of studies that investigate effect of the 5-HTTLPR polymorphism on hippocampal volumes in major depressive disorder are inconclusive. Method: We looked for a relationship between the 5-HTTLPR polymorphism and hippocampal volumes in 44 depressed patients (mean age ± SD 33.6 ± 9.5 years) and 43 healthy controls (30.4 ± 6.7 years). Region of interest analysis was conducted on the images acquired via MRI. Results: Although hippocampal volumes were similar in healthy and patient groups, there was a significant interaction between genotype and diagnosis on hippocampus volumes. Post-hoc ANCOVA showed that hippocampal volumes of S/S homozygous depressed patients were smaller compared to healthy controls in both hemispheres. Conclusion: The 5-HTTLPR polymorphism has an effect on hippocampal volumes of depressed patients, which is apparent only in S/S genotype. It seems that decreased neurogenesis by effects of reduced serotoninergic transmission may be responsible for smaller hippocampal volumes observed in S/S homozygous depressed patients.

Clinical and molecular aspects of Turkish familial hemophagocytic lymphohistiocytosis patients with perforin mutations

The aim of this study was to elucidate the pathologic sequence changes and associated clinical phenotypes in 9 new patients showing homozygosity for perforin gene among a total of 37 (24%) Turkish FHL families studied by linkage analysis. These 9 unrelated patients (5M/4F) were coming from consanguineous families and their presentation ages of systemic symptoms were ranged from birth to 15 years. Direct sequencing of coding exons of the perforin gene led to the identification of five different homozygous alterations. The nonsense W374X mutation was identified in three patients while four different missense mutations namely G149S, V50M, A91V and novel A523D were detected in the rest six patients.

Is vitamin D hypothesis for schizophrenia valid? Independent segregation of psychosis in a family with vitamin-D-dependent rickets type IIA.

The vitamin D hypothesis of schizophrenia is a recent concept bringing together old observations on environmental risk factors and new findings on the neurodevelopmental effects of vitamin D. Candidate genes related to the vitamin D endocrine system have not yet been fully explored for this purpose. The coexistence of vitamin-D-dependent-rickets type II with alopecia (VDDR IIA) and different forms of psychosis in the same inbred family has provided us with an opportunity to investigate the presumed relationship between vitamin D deficiency and psychosis. Psychiatric examination and molecular genetic studies were performed in this family overloaded with psychotic disorders and VDDR IIA. Forty members were evaluated in order to describe their phenotypic features. The family was tested for a linkage to the chromosome 12q12-q14 region where the vitamin D receptor (VDR) gene is located. Psychosis was the common phenotype in the 18 psychiatrically affected members. Pedigree analysis did not show a cosegregation of psychosis and rickets. Lod scores were not significant to prove a linkage between psychosis and VDR locus. The authors concluded that (1) the neurodevelopmental consequences of vitamin D deficiency do not play a causative role in psychotic disorders, (2) these two syndromes are inherited independently, and (3) vitamin D deficiency does not act as a risk factor in subjects susceptible to psychosis.

Effects of methylprednisolone on human myeloid leukemic cells in vitro

We have demonstrated previously that high‐dose methylprednisolone treatment induces differentiation and apoptosis of leukemic cells in patients with different morphological subtypes of acute myeloblastic leukemia (AML) in vivo. In the present study, we investigated the in vitro effects of high (10−3 M) and low (10−6 M) concentrations of methylprednisolone (MP) on freshly isolated bone marrow leukemic cells from nine newly diagnosed patients with AML by light and electron microscopy (EM) and agarose gel electrophoresis. A marked increase in MP‐induced apoptosis of leukemic cells, with a maximum effect at 24 hr of exposure to both low and high concentrations of MP (10−6 M and 10−3 M), was demonstrated by light microscopy in cultures of four (three with AML‐M1 and one with AML‐M7) of the nine patients. In three cases, the increase in the number of apoptotic cells induced by high‐concentration MP was approximately twice that observed when the lower concentration was used. A few apoptotic cells were detected in the cultures from the other five patients. However, a typical DNA ladder pattern of apoptosis was observed on gel electrophoresis of MP‐treated leukemic cells from one patient (AML‐M1) after 2 hr of incubation with both high‐ and low‐MP concentrations. In two patients, a nonspecific DNA smear was observed only when high‐concentration MP was used. The increase in differentiated leukemic cells induced by MP was also dose dependent, and was observed in cultures from all but one patient. Morphological features of apoptosis and differentiation were also confirmed by EM studies. The results of the present study, together with our previous clinical experience, suggest that MP, especially at high doses, could have a significant role in the treatment of some AML patients by inducing apoptosis and differentiation of leukemic cells. Am. J. Hematol. 60:255–259, 1999.

Neonatal primary hemophagocytic lymphohistiocytosis in Turkish children.

Although the data on hemophagocytic lymphohistiocytosis (HLH) has gradually increased, the neonatal-onset HLH patients have usually been reported as case reports or together with other age groups of patients. The aim of this study was to draw attention to the clinical and laboratory characteristics of neonatal HLH cases. Herein, the data of 8 primary, neonatal-onset HLH patients are reported. Mutational analyses were performed in 7 of the patients and mutations in UNC13D gene were detected in 3 of the patients, whereas 2 patients were found to have perforin gene mutation. Four of the patients were symptomatic within the initial 10 days of life. One patient with perforin mutation (1122 G>A) had a very severe clinical course and died on the seventh day of life before receiving any specific treatment. Another patient with UNC13D 2783 G>C, who became symptomatic on the sixth day of life, underwent early hematopoietic stem cell transplantation and is currently alive at 8 years of age. Two of these 4 patients had extensively high serum ferritin levels mimicking neonatal hemochromatosis. Of the 4 patients who became symptomatic after 20th day of newborn period, 1 was found to have perforin gene mutation (445 G>A) and 2 siblings were detected to have a missense mutation in UNC13D (640 C>T) gene. The latter patients with UNC13D mutations could survive 3 and 4 months, although their parents ceased therapy. The patient with perforin mutation survived 11 months.

Prothrombin G20210A mutation in Turkish children with thrombosis and the frequency of prothrombin C20209T.

The prothrombin G20210A mutation has been described as the second most common genetic risk factor in thrombotic patients. Recently a new prothrombin gene variant namely prothrombin C20209T has also been found to be associated with thrombosis. In the present study the frequency of these two thrombin variants have been searched in two different groups. Group 1: A total of 377 children with thrombosis were analyzed during 7 years between January 1997 and 2004 and screened for prothrombin G20210A mutation. Twenty-four of 387 children (6.3%) with thrombosis were diagnosed as having PT G20210A mutation. The mean age of the patients was 6.1 years (median: 6 years, range: 4 months to 17 years, 15 male, 9 female). Six of 24 children were below 2 years of age (25%). Fifteen of 24 children (62.5%) had arterial thrombosis, most of whom (93.3%) had cerebral infarct. Group 2: The prothrombin C20209T variant has been analyzed in 200 thrombotic patients and in 200 healthy subjects. None of the thrombotic patients and healthy individuals carried the prothrombin C20209T variant. In conclusion, arterial thrombosis as the cerebral infarct is the most prominent type of thrombosis in children with prothrombin G20210A mutation. It seems that the prothrombin C20209T variant is not an important risk factor for the population studied.

Assessment of clinical and laboratory presentations of familial hemophagocytic lymphohistiocytosis patients with homozygous W374X mutation

Homozygous W374X mutation was identified in unrelated 13 patients (6M/7F) from consanguineous families, 62% of which had history of deceased sibling. Haplotype analysis provided evidence for the probable existence of a founder effect. Age at disease onset ranged from 1 day to 5.5 months (median 2 months). Hepatic dysfunction was observed in 69%, ascite 62%, hypertriglyceridemia 77%, each hyperferritinemia and hypofibrinogenemia 85%, CNS involvement 46% of patients while birth weights were in normal range. Those with very high ferritin (>20,000ng/ml) had extremely low fibrinogen levels. Two-thirds of patients receiving HLH protocol died within 20 days of therapy.

ORIGINAL ARTICLE: Placental Fas/Fas Ligand Expression in Early Pregnancy Losses

Problem  The aim of this study was to compare the expression levels of Fas and Fas ligand (FasL) in first‐trimester placentas obtained from spontaneous abortions in patients with antiphospholipid antibody syndrome (APS) or factor V (FV) Leiden mutation, compared with values in placentas from induced abortions in patients negative for these conditions.