Monoallelic and biallelic mutations in MAB21L2 cause a spectrum of major eye malformations.

We identified four different missense mutations in the single-exon gene MAB21L2 in eight individuals with bilateral eye malformations from five unrelated families via three independent exome sequencing projects. Three mutational events altered the same amino acid (Arg51), and two were identical de novo mutations (c.151C>T [p.Arg51Cys]) in unrelated children with bilateral anophthalmia, intellectual disability, and rhizomelic skeletal dysplasia. c.152G>A (p.Arg51His) segregated with autosomal-dominant bilateral colobomatous microphthalmia in a large multiplex family. The fourth heterozygous mutation (c.145G>A [p.Glu49Lys]) affected an amino acid within two residues of Arg51 in an adult male with bilateral colobomata. In a fifth family, a homozygous mutation (c.740G>A [p.Arg247Gln]) altering a different region of the protein was identified in two male siblings with bilateral retinal colobomata. In mouse embryos, Mab21l2 showed strong expression in the developing eye, pharyngeal arches, and limb bud. As predicted by structural homology, wild-type MAB21L2 bound single-stranded RNA, whereas this activity was lost in all altered forms of the protein. MAB21L2 had no detectable nucleotidyltransferase activity in vitro, and its function remains unknown. Induced expression of wild-type MAB21L2 in human embryonic kidney 293 cells increased phospho-ERK (pERK1/2) signaling. Compared to the wild-type and p.Arg247Gln proteins, the proteins with the Glu49 and Arg51 variants had increased stability. Abnormal persistence of pERK1/2 signaling in MAB21L2-expressing cells during development is a plausible pathogenic mechanism for the heterozygous mutations. The phenotype associated with the homozygous mutation might be a consequence of complete loss of MAB21L2 RNA binding, although the cellular function of this interaction remains unknown.

Delayed Puberty and Gonadal Failure in Patients with HAX1 Mutation.

PURPOSE: Homozygous mutations in the HAX1 gene cause an autosomal recessive form of severe congenital neutropenia (SCN). There are limited data on cases of gonadal insufficiency that involve the HAX1 gene mutation. We aimed to evaluate the pubertal development and gonadal functions of our patients with a p.Trp44X mutation in the HAX1 gene. METHOD: Pubertal development, physical and laboratory findings of one male and seven female patients with HAX1 deficiency were evaluated. RESULTS: The age of the patients was between 13 and 25 years. All female patients were diagnosed with primary ovarian insufficiency (POI) based on amenorrhea and elevated gonadotropins. The ovary volumes in female patients were determined to be smaller than normal for their age through sonographic studies. Short stature associated with gonadal insufficiency was also observed in three patients. CONCLUSION: The HAX1 gene is important for ovarian development, in which a p.Trp44X mutation may cause POI in female patients. It is crucial to follow up and evaluate the gonadal functions of female patients in such cases.

An Unusual Case of LCHAD Deficiency Presenting With a Clinical Picture of Hemophagocytic Lymphohistiocytosis: Secondary HLH or Coincidence?

There are published reports stating that some of the congenital metabolic diseases, such as lysinuric protein intolerance, multiple sulphatase deficiency, galactosemia, Gaucher disease, Pearson syndrome, and galactosialidosis, might lead to secondary hemophagocytic lymphohistiocytosis (HLH). However, to date, to our knowledge, the long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) deficiency has never been investigated among patients with HLH. Here, we report on a patient who was referred to our institution for a differential diagnosis of pancytopenia, liver failure, and rhabdomyolysis. The patient was diagnosed with HLH. Further investigation revealed an underlying diagnosis of the LCHAD deficiency. Our case was reported to contribute to the literature, as well as the HLH clinic, emphasizing the consideration of LCHAD deficiency, especially in 1 to 6 months' old infants with laboratory findings of hypoglycemia, metabolic acidosis, and elevated creatine kinase.

Association of GSTM1, GSTT1, GSTP1-ILE105VAL and ACE I/D polymorphisms with ankylosing spondylitis.

Ankylosing spondylitis (AS) is a chronic inflammatory disease of unknown origin. The aim of this study is to clarify the relationships between susceptibility and severity of AS and GST-mu1 (GSTM1), GST-theta1 (GSTT1), GST-pi1 (GSTP1)-Ile105Val and angiotensin-converting enzyme (ACE) I/D polymorphisms in AS patients. One hundred thirty-eight AS patients and seventy-one healthy controls were enrolled in this study. Erythrocyte sedimentation rate and C-reactive protein (CRP) levels of the AS patients were recorded. The scores of the numeric rating scale (NRS) pain, the Bath Ankylosing Spondylitis Activity Index, the Bath Ankylosing Spondylitis Metrology Index and the Bath Ankylosing Spondylitis Functional Index were calculated. The genotypes distributions and allele frequencies of GSTM1, GSTT1, GSTP1-Ile105Val and ACE I/D polymorphisms were compared between patients and healthy controls. The Multiplex polymerase chain reaction (PCR) and the PCR-restriction fragment length polymorphism methods were used to detect the polymorphisms of ACE I/D, the GSTT1 and GSTM1 genes and the GSTP1-Ile105Val polymorphism, respectively. There were significantly higher levels of the GSTT1 null and the ACE II genotypes in AS patients compared to those in healthy controls (p = 0.002 and 0.005, respectively). We found significantly higher levels of CRP and the NRS pain scores in the patients with ACE ID or DD genotypes compared to those in the patients with ACE II genotypes (p = 0.005 and 0.035, respectively). The present results showed that genes involved in protection from oxidative stress and ACE gene may influence disease development and course in AS.

Reanalysis of human blastocysts with different molecular genetic screening platforms reveals significant discordance in ploidy status.

OBJECTIVE: The objective of this study is to determine mosaicism and its effect on blastocysts; abnormal blastocysts determined by molecular testing were sequentially biopsied and retested. MATERIAL AND METHOD: We re-biopsied 37 blastocyst-stage abnormal embryos from eight patients, which were reanalyzed to determine the level of concordance between biopsies and inter-laboratory congruence between reputable commercial PGS laboratories. RESULTS: The main outcome measures were intra-embryo variation between sequential embryo biopsies and inter-laboratory variation between two PGS laboratories. The compatibility between both aCGH and NGS was found to be 11 % (3/27). Importantly, 9/27 (33 %) of embryos originally reported to be aneuploid, upon repeat assessment, were found to be euploid. The concurrence for SNP array and NGS was 50 % (3/6), and 17 % (1/6) of these abnormal embryos tested normal upon re-evaluation with NGS. NGS resulted 41 % (11/27) normal results when 27 of CGH abnormal embryos were retested. Concordance between aCGH and NGS was 4 % (1/27) whereas in three instances, gender discrepancy was observed with NGS when aCGH abnormal embryos were reanalyzed. CONCLUSIONS: The results of these studies reinforce the prevalence of inconsistencies during PGS evaluation of trophectoderm biopsies possibly due to variations in platform sensitivity and heightening concerns over the clinical tractability of such technology in human ARTs..

Glutathione S-Transferase M1 and T1 Gene Polymorphisms in Patients with Chronic Plaque-Type Psoriasis: A Case-Control Study.

OBJECTIVE: To determine the role of glutathione S-transferase (GST) isoenzyme polymorphisms as susceptibility factors in patients with psoriasis in a Turkish cohort. SUBJECTS AND METHODS: In this case-control study, 105 patients with plaque-type psoriasis and 102 healthy controls were recruited from the dermatology outpatient clinics of two university hospitals. Genomic DNA was extracted from whole blood using a DZ DNA isolation kit. Multiplex PCR was used to determine GSTM1 and GSTT1 polymorphisms in the isolated DNAs. RESULTS: Of the 150 patients with psoriasis, 83 (79%) were identified with the GSTT1 genotype and 22 (21%) with the null genotype. Of the 102 patients in the control group, 69 (67.6%) subjects were identified with the GSTT1 genotype and 33 (32.4%) with the null genotype. There was no significant difference between the patient and control groups (p = 0.063). Regarding the GSTM1 polymorphism, 54 (51.4%) patients were identified with this genotype and 51 (48.6%) with the null genotype; in the control group, 50 (49%) were identified with this genotype and 52 (51%) with the null genotype. Again there was no statistically significant difference between the groups (p = 0.957). CONCLUSION: In this Turkish cohort of patients with psoriasis, neither GSTT1 nor GSTM1 polymorphisms were associated with disease susceptibility. Larger studies with a wider range of GST isoenzyme are needed.

Oxytocin system social function impacts in children with attention-deficit/hyperactivity disorder.

To investigate relationships between the polymorphisms and social functioning of children with Attention Deficit/Hyperactivity Disorder (ADHD), according to the polymorphism of three oxytocin receptor (OXTR) genes (rs53576, rs13316193, and and rs2268493). A total of 198 children-studying in the same primary and secondary school and matched in terms of age and gender (99 ADHD, 99 control)-were included in this study. The Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime Version was administered to establish the clinical diagnosis. The Social Reciprocity Scale (SRS) was applied to evaluate social functioning. The total genomic DNA was isolated from buccal mucosa samples. No significant differences were determined between the ADHD and control groups in terms of rs2268493, rs13316193, and rs53576 genotype distribution (P = 0.078, P = 0.330, and P = 0.149, respectively). However, the control group T allele frequency in the OXTR Single Nucleotide Polymorphism (SNP) rs2268493 was significantly higher than the ADHD group (P = 0.024). Compared to the control group, the ADHD group had a higher score on the SRS scale (SRS total; Z = -21,135, P < 0.001). No significant difference existed in the SRS scale scores between the children with the T/T genotype and the C allele in the ADHD group (SRS total; Z = -0.543, P = 0.587). The allele distribution of the OXTR gene SNP rs2268493 was significantly different in the ADHD group, compared to the control group. This observation is important in understanding the underlying biological infrastructure in ADHD and developing treatment modalities.

The prevalence of 4G/5G polymorphism of plasminogen activator inhibitor-1 (PAI-1) gene in central serous chorioretinopathy and its association with plasma PAI-1 levels.

CONTEXT: Central serous chorioretinopathy (CSCR) is a poorly understood disease and the choroidal circulation abnormality induced by the plasminogen activator inhibitor type 1 (PAI-1) seems to be associated with the pathogenesis. There are many reports indicating that 4 G/5 G polymorphism of the PAI-1 gene is a risk factor for several diseases related to the elevated serum levels of PAI-1. OBJECTIVE: To evaluate the 4 G/5 G polymorphism of the PAI-1 gene and its association with serum levels of PAI-1 in acute CSCR patients. MATERIALS AND METHODS: Sixty CSCR patients and 50 healthy control patients were included. The PAI-1 4 G/5 G was genotyped using the polymerase chain reaction-restriction technique. Serum PAI-1 level was measured using enzyme-linked immunosorbent assay. Demographic data consisting of age, sex, body mass index (BMI) as well as genotype disturbances and serum PAI-1 levels were compared between the groups. Statistical significance for differences in the serum PAI-1 levels of each group with different genotypes was also analyzed. RESULTS: The CSCR group consisted of 40 male (66.7%) and 20 female (33.3%) patients with a mean age of 46.7 ± 8.39 years. The control group consisted of 32 male (64%) and 18 female (36%) healthy subjects with a mean age of 45.8 ± 8.39 years. There was no statistically significant difference between the groups in terms of age, sex and BMI. In the CSCR group the genotype frequencies were 4 G/4G: 30% (n = 18), 4G/5 G: 50% (n = 30), 5 G/5G: 20% (n = 12) and in the control group genotype frequencies were 34% (n = 17), 42% (n = 21) and 24% (n = 12), respectively. There was no statistically significant difference in the distribution of genotypes among the groups (chi-squared, p = 0.70). The CSCR group had a significantly higher serum PAI-1 concentration than the control group (p = 0.001). In both groups the mean plasma PAI-1 concentration did not vary significantly among the different genotypes (p > 0.05). DISCUSSION AND CONCLUSION: Although our results demonstrated that the patients with acute CSCR have higher serum PAI-1 concentrations than the controls, no significant difference was found in the genotype disturbances of the PAI-1 gene between the groups. The current study indicates that 4 G/5 G polymorphism in the promoter of the PAI-1 gene cannot be considered a risk factor for the elevated serum PAI-1 levels and consequent development of CSCR.

Diffuse Leptomeningeal Glioneuronal Tumors: A Case Series of Five Patients with Parenchymal Forms and an Analysis of the Diagnostic Challenges, Treatment Options and Outcomes.

BACKGROUND: Diffuse leptomeningeal glioneuronal tumors (DL-GNT) are rare glioneuronal neoplasms with oligodendroglioma-like cells. These tumors can present as a dominant intracranial mass or as a solitary spinal cord mass without leptomeningeal involvement. In this study, we aimed to determine the magnetic resonance imaging and histopathological features, treatment modalities, and clinical outcomes of the parenchymal forms of DL-GNTs. METHODS: This is a retrospective three-center case series study of 5 patients with a confirmed parenchymal form of DLGTs, out of which 4 patients were adults. Brain and spinal cord MR imaging were performed in all patients at either 1.5 or 3T. The patients' age ranged from 5 years to 50 years with a mean age of 27.6 years at presentation. RESULTS: Four of the tumors were located in the frontal lobe, and one in the tectum. They were usually solid-cystic enhancing tumors as the other mixed neuronal-glial tumors. All of the tumors had an extension to the superficial surface of a cerebral hemisphere. One had systemic bone metastases. The clinical signs and symptoms of the parenchymal form varied based on the location of the mass, in contrast to the leptomeningeal form associated with hydrocephalus. In one case, the tumor's initial grade was defined as intermediate. The initial histopathology of the two cases was low-grade and no upgrade occurred in the follow-up period. In two cases, although the tumors were low grade initially, they progressed to an anaplastic form in the follow-up period. CONCLUSION: The parenchymal form of DL-GNTs is common in adults. Extension to the superficial surface of a cerebral hemisphere is a distinctive imaging feature. Systemic osseous metastasis may occur. Due to the presence of common histopathological features, including the biphasic composition of glial and neuronal cell elements and oligodendroglioma-like cells, a proposed classification approach might be more beneficial for the histopathological and imaging description, and management of the glioneuronal tumors with oligodendroglioma-like features.

Comparison of aneuploidy frequencies between in vitro matured and unstimulated cycles oocytes by metaphase comparative genomic hybridization (mCGH).

A common observation after in vitro matured oocyte is that they yield poorer embryo quality compared to their in vivo counterparts. This study was designed to assess chromosomal status with metaphase comparative genomic hybridization after in vitro maturation (IVM) in unstimulated cycles and compare the results with those obtained after in vivo maturation. Patients without any obstetrical or gynecological pathology were admitted into the study. IVM oocytes were collected 36 h post hCG and matured in vitro at 37°C in 5% O(2), 6% CO(2), and 89% air for 36 h. All matured (metaphase II) oocytes were subject to polar body 1 (PB-1) biopsy and vitrified individually. PB-1 samples were transferred into 0.25 cc PCR tubes containing 2.5 µl of PBS. PB-1 samples from 12 IVM patients were studied. Twenty-six out of 63 PB-1 samples (41%) were determined as euploid and 37 samples (59%) were aneuploid, whereas these values were 42% euploid and 58% aneuploid in the control group (in vivo matured oocytes). No statistical differences were found between the IVM and the control groups for euploid-aneuploid samples (P = 0.900). More aneuploidy was observed on chromosomes 11, 13, 15, 21, and 22 after IVM. Results show a non-significant rate of abnormal PB-1 formation after IVM compared to in vivo maturation. More aneuploidy was observed in chromosomes 11, 13, 15, 21, and 22 in the IVM group.

Evaluation of the JAK2-V617F gene mutation in Turkish patients with essential thrombocythemia and polycythemia vera.

An activating mutation of Janus kinase 2 (JAK2-V617F) was previously described in chronic myeloproliferative disorders (MPD). In previously published studies, the frequency of the JAK2-V617F mutation was determined to be 80-90 % for patients with polycythemia vera (PV) and 40-70 % for essential thrombocythemia (ET). In this study, we analyzed the relationship between the JAK2-V617F mutation and clinical-hematological parameters in Turkish patients with MPD and compared these findings with published studies from other geographic regions. A total of 148 patients were studied; of which, 70 were diagnosed with PV and 78 with ET. The mutation status of JAK2 was determined using a tetra-primer polymerase chain reaction. We found that 80 % of the PV group and 42 % of the ET group were positive for the JAK2-V617F mutation. When all patients were analyzed, the levels of white blood cells, hemoglobin and splenomegaly were significantly different in patients with the JAK2-V617F mutation (p < 0.05). To our knowledge, this study is the first to evaluate the relationship between MPD and JAK2-V617F in Turkish patients. The JAK2-V617F mutation is frequently detected in the Turkish patients with MPD, and especially in patients with PV. Hence, it would be useful to include JAK2 mutation screening in the initial evaluation of patients suspected to have MPD.

ACE gene I/D polymorphism and risk of sarcoidosis development in Turkish patients.

INTRODUCTION: Etiology of sarcoidosis is unknown but the prevalence of disease in different ethnic groups and identical twins, family characteristics indicate that genetic predisposition is a possible factor. The angiotensin-converting enzyme (ACE) has been implicated in the pahophysiology of sarcoidosis. The aim of this study is to investigate the influence of a polymorphism in I/D (Insertion/Deletion) of the ACE gene on the susceptibility to sarcoidosis. PATIENTS AND METHODS: Our study included 70 Turkish patients who had histopathological diagnosis of sarcoidosis and 69 healthy age and sex matched control subjects. Polymerase chain reaction was used for analysing an I/D polymorphism in the gene coding for ACE. Genotyping was done according to bands that were formed on the agarose gel electrophoresis. Chi-square test was used for statistical analysis and p< 0.05 was accepted as significance. RESULTS: Although the D allele was more frequent in the sarcoidosis patients group, the frequency of the D allele was 67% and 54% respectively in the sarcoidosis and the control group. No significant difference in allele frequencies of I/I, I/D, D/D polymorphisms was observed between the sarcoidosis and control group (p> 0.05). Similarly allele frequencies of I/I, I/D, D/D polymorphisms was not different between sarcoidosis patients with extrapulmonary involvement and sarcoidosis patients without extrapulmonary involvement (p> 0.05). CONCLUSION: Our findings have showed that contribution of ACE gene polymorphisms to susceptibility of disease development in Turkish sarcoidosis patients is not different from the healthy control subjects.

Novel TSHR mutations in consanguineous families with congenital nongoitrous hypothyroidism.

OBJECTIVE: Nonsyndromic autosomal recessively inherited nongoitrous congenital hypothyroidism (CHNG) can be caused by mutations in TSHR, PAX8, TSHB and NKX2-5. We aimed to investigate mutational frequencies of these genes and genotype/phenotype correlations in consanguineous families with CHNG. DESIGN: Because consanguinity in individuals with a presumptive genetic condition is often an indicator of an autosomal recessive inheritance and allows firmer correlations to be established between genotype and phenotype, we planned to execute our study in consanguineous families. PATIENTS: Hundred and thirty-nine children with CHNG phenotype born to consanguineous families. MEASUREMENTS: First, we investigated cases for evidence of linkage to the four known CHNG genes by microsatellite marker analysis. Mutation analysis by direct sequencing was then performed in those cases in whom linkage to the relevant candidate gene could not be excluded. In addition, in silico analysis of the predicted structural effects of TSHR mutations was performed and related to the mutation-specific disease phenotype. RESULTS: Homozygous germline TSHR mutations were detected in six families (5%), but no mutations were detected in PAX8, TSHB and NKX2-5. Four of TSHR mutations had not previously been described. Genotype-phenotype correlations were established and found to be related to the predicted structural effects of the mutations. CONCLUSIONS: Known causative genes account for the development of CHNG only in a minority of cases, and our cohort should provide a powerful resource to identify novel causative genes and to delineate the extent of locus heterogeneity in autosomal recessively inherited CHNG.

Sudden blastic crisis and additional chromosomal abnormalities during chronic myeloid leukemia in the imatinib era.

Imatinib has shown significant clinical and cytogenetic success in the treatment of chronic myeloid leukemia. Although resistance has been observed in a proportion of patients, sudden blastic crisis is a rare event during imatinib therapy. We describe a 24-year-old male patient with Philadelphia chromosome-positive chronic myeloid leukemia in chronic phase who developed sudden blastic crisis in the 24th month of imatinib therapy, with loss of complete cytogenetic response. At this time, the patient had splenomegaly, severe anemia, thrombocytopenia, and leukocytosis. Bone marrow aspirate revealed the presence of massive blastic infiltration with myeloid morphology. Flow cytometric analysis of the bone marrow cells showed positivity for CD45, CD34, CD13, CD33, CD19, CD41, CD61, and glycophorin-A. Trephine biopsy specimens showed 100% cellular marrow with diffuse infiltrate by blasts. A reticulin stain of the bone marrow biopsy section demonstrated severe diffuse fibrosis. Cytogenetic analysis by fluorescence in situ hybridization (FISH) revealed that 92% of the cells were positive for the BCR/ABL fusion signal and had increased copy numbers for chromosomes 8, 13, 19, and 21. The patient's prognosis was unfavorable. In conclusion, chronic myeloid leukemia remains complex and includes unanswered questions. The presented case with a rare event during imatinib therapy highlights the need for the continued monitoring of residual disease and the development of strategies to eliminate residual leukemia cells in patients showing a complete cytogenetic response.

AML1 amplification and 17q25 deletion in a case of childhood acute lymphoblastic leukemia.

We report a case of childhood acute lymphoblastic leukemia (ALL) with both acute myeloid leukemia 1 (AML1) amplification and 17q25 deletion. AML1 gene is located on 21q22 and encodes a transcription factor. AML1 amplification is a common finding in childhood ALL, and itis observed as an increase in gene copy number by the FISH analysis. The mechanism of AML1 amplification is not associated with AML1 gene mutations. The 17q25 is a gene-rich chromosomal location and distinct abnormalities of this region have been observed in previous cases of different kinds of leukemia. Deletion of the 17q25 region has been reported in two leukemia patients. Septin 9 (SEPT9) and survivin genes are located on 17q25. High expression of these genes and AML1 amplification are regarded as markers in tumorigenesis and disease progression; however, more data are needed for accurate prognostic evaluation.

Pantothenate kinase-associated neurodegeneration (PKAN): molecular confirmation of a Turkish patient with a rare frameshift mutation in the coding region of the PANK2 gene.

Here we report the clinical, neuroimaging, and molecular findings of a classic pantothenate kinase-associated neurodegeneration (PKAN) patient of Turkish origin. Our patient is the first reported case of PKAN in Turkey with molecular genetic confirmation of the diagnosis. The frameshift mutation c.821_822delCT of the PANK2 gene detected in our patient has only been described in such classic patients to date, and our case provides further evidence of the association of this mutation with the classic PKAN phenotype. Since this mutation is a rare disease-causing mutation in other populations, further studies of more Turkish PKAN patients will show if it is the result of a founder effect in this population. In our case, molecular diagnosis allowed accurate prenatal genetic testing and counseling for this family. This case report highlights the importance of magnetic resonance imaging and molecular investigation in children who have progressive neurodegenerative symptoms of parkinsonism, dystonia, pyramidal features, and dementia.

The potential utility of real-time PCR of the 16S-rRNA gene in the diagnosis of neonatal sepsis.

Istanbullu K, Köksal N, Çetinkaya M, Özkan H, Yakut T, Karkucak M, Dogan H. The potential utility of real-time PCR of the 16S-rRNA gene in the diagnosis of neonatal sepsis. Turk J Pediatr 2019; 61: 493-499. The purpose of this study was to evaluate the efficacy of real-time polymerase chain reaction (PCR) of the 16S rRNA gene in diagnosis of neonatal sepsis and compare it with conventional blood culture. A total of 150 infants were enrolled in this prospective study. The infants were classified into two groups: sepsis group (n=100) and control group (n=50). Blood samples for complete blood count, C-reactive protein, procalcitonin, serum-amyloid A, blood culture and PCR were obtained before initiating antibiotic treatment. Eight specific probes were used to perform PCR analysis for detection of 8 different microorganisms. The positivity rates of blood culture and PCR were found as 11% and 3%, respectively. The diagnosis of neonatal sepsis by PCR revealed a 16.6 % sensitivity, 97.8 % specificity, 33.3% positive predictive value and 94.8% negative predictive value compared with the blood culture. This study showed a low sensitivity of PCR of the 16S rRNA gene in the diagnosis of neonatal sepsis. This may be associated with the identification of rare microorganisms in the blood culture that were not included to PCR analysis. Implementation of all suspectible microorganisms into PCR assay may increase the sensitivity of 16S rRNA gene PCR in diagnosis of neonatal sepsis.

Correlation of chromosomal imbalances by comparative genomic hybridization and expression of EGFR, PTEN, p53, and MIB-1 in diffuse gliomas.

The histological subclassification of gliomas is increasingly assisted by the underlying molecular genetics which has major importance in guiding clinical management of the disease. However, the assessment of several molecular events for improving clinical care remains a challenge. Herein, we report on comparative genomic hybridization (CGH) and immunohistochemical (IHC) assessment of EGFR, PTEN, p53, and MIB-1 expression in 13 oligodendrogliomas (10 WHO grade II, 3 WHO grade III), one oligoastrocytoma (WHO grade III) and 23 high-grade astrocytomas (3 WHO grade III, 20 glioblastoma multiforme). The most frequent imbalances in oligodendroglial tumors including the oligoastrocytic case were, in decreasing order of frequency, +7q, -1p, and -4q and in astrocytomas +7q, -10q, +7p, -9p, -10p, +20q, and +20p. Some individual imbalances were associated with increasing numbers of chromosomal changes, that were +7q in both oligodendrogliomas and astrocytomas, and -9p, -10q, +20p, and +20q in astrocytomas. The markers p53 and MIB-1 were significantly higher expressed in astrocytomas than in oligodendrogliomas and expression levels of p53 and EGFR were inversely associated within the astrocytic group. In addition, p53 overexpression correlated positively with +7q and negatively with -1p in the oligodendroglial group whereas EGFR overexpression correlated positively with -1p in the oligodendroglial and positively with +7p and -10p in the astrocytic group. Short overall survival was significantly associated with +7p and -10q in astrocytomas. Collectively, these results contribute to the increasing clinical relevance of assessing tumor biological markers in gliomas.

Low frequency of p53 and k-ras codon 12 mutations in non-small cell lung carcinoma (NSCLC) tumors and surgical margins.

AIMS AND BACKGROUND: Lung cancer is one of the most common cancers and has became a predominant cause of cancer-related death throughout the world. The k-ras codon 12 mutation, which is the most common lung cancer mutation, is found in 15 to 30% of all lung cancers. Furthermore, the p53 gene has a very important role in the biological properties of tumor cells, and it is mutated in about 50% of non-small cell lung cancers. Residual tumor cells remain in surgical margins diagnosed as tumor free by histopathological techniques, and they can play a role in forming any local recurrence. Molecular methods may be exploited that are sensitive enough to detect small numbers of tumor cells. METHODS: In the present study, we examined p53 gene mutations and k-ras codon 12 mutations from the tumor samples and surgical margins of 34 non-small-cell lung cancer patients. P53 gene mutations were analyzed by single strand conformational polymorphism analysis, heterodublex analysis and DNA sequencing. K-ras codon 12 mutations were analyzed by the mutagenic PCR-restricted fragment length polymorphism method. RESULTS: A p53 mutation was detected only in primary tumors of 3 out of 34 patients (8.82%). These mutations were clustered in exon 5. Moreover, a k-ras codon 12 mutation was detected in both the primary tumor and the surgical margin tissues of 2 out of 34 patients (5.88%). CONCLUSIONS: The detected mutation rate was low, in the range given in the literature. We think that different mechanisms related to other genes and individual genetic differences might play a role in cancer formation in our study group. We believe that molecular studies are necessary to identify biomarkers and to determine genetic alterations in histopathologically normal surgical margins.