PCDH19-clustering epilepsy, pathophysiology and clinical significance.

PCDH19 clustering epilepsy (PCDH19-CE) is an X-linked epilepsy disorder associated with intellectual disability (ID) and behavioral disturbances, which is caused by PCDH19 gene variants. PCDH19 pathogenic variant leads to epilepsy in heterozygous females, not in hemizygous males and the inheritance pattern is unusual. The hypothesis of cellular interference was described as a key pathogenic mechanism. According to that, males do not develop the disease because of the uniform expression of PCDH19 (variant or wild type) unless they have a somatic variation. We conducted a literature review on PCDH19-CE pathophysiology and concluded that other significant mechanisms could contribute to pathogenesis including: asymmetric cell division and heterochrony, female-related allopregnanolone deficiency, altered steroid gene expression, decreased Gamma-aminobutyric acid receptor A (GABAA) function, and blood-brain barrier (BBB) dysfunction. Being aware of these mechanisms helps us when we should decide which therapeutic option is more suitable for which patient.

Biallelic variants in TMEM222 cause a new autosomal recessive neurodevelopmental disorder.

PURPOSE: To elucidate the novel molecular cause in families with a new autosomal recessive neurodevelopmental disorder. METHODS: A combination of exome sequencing and gene matching tools was used to identify pathogenic variants in 17 individuals. Quantitative reverse transcription polymerase chain reaction (RT-qPCR) and subcellular localization studies were used to characterize gene expression profile and localization. RESULTS: Biallelic variants in the TMEM222 gene were identified in 17 individuals from nine unrelated families, presenting with intellectual disability and variable other features, such as aggressive behavior, shy character, body tremors, decreased muscle mass in the lower extremities, and mild hypotonia. We found relatively high TMEM222 expression levels in the human brain, especially in the parietal and occipital cortex. Additionally, subcellular localization analysis in human neurons derived from induced pluripotent stem cells (iPSCs) revealed that TMEM222 localizes to early endosomes in the synapses of mature iPSC-derived neurons. CONCLUSION: Our findings support a role for TMEM222 in brain development and function and adds variants in the gene TMEM222 as a novel underlying cause of an autosomal recessive neurodevelopmental disorder.

Potential voriconazole associated posterior reversible leukoencephalopathy in children with malignancies: Report of two cases.

INTRODUCTION: The fungal infection has become severe morbidity amongst patients with malignancy. Voriconazole, a new generation of triazole, has shown excellent results in treating invasive fungal infections. CASE REPORT: Herein, we report two cases of posterior reversible encephalopathy syndrome (PRES), which induced after voriconazole exposure.Management and outcome: Magnetic resonance imaging, and the serum level of voriconazole were investigated in both patients to assess toxicity. The role of methotrexate, as one of the possible causes of PRES, is weakened significantly through precise assessing diffusion-weighted images on magnetic resonance imaging. DISCUSSION: These unique cases emphasize that voriconazole can induce PRES even at therapeutic levels. Therefore, in the case of neurotoxicity, PRES must be considered, and voriconazole should discontinue. The prognosis seemed promising when voriconazole stopped immediately after clinical suspicion.

Role of the 820 A/G variant in the IGF-2 gene and recurrent spontaneous abortion in southern Iran: A cross-sectional study.

BACKGROUND: Insulin-like growth factor-2 (IGF-2) is a polypeptide growth factor and one of the first genes expressed prior to the implantation of the embryo, with its highest expression in the placental cells. Its activity strongly depends on the genomic imprinting, and the result of the loss of genetic imprinting is the termination of the early stages of embryonic development, which can lead to recurrent spontaneous abortion. OBJECTIVE: This cross-sectional study aimed to investigate the role of 820A/G variant of the IGF-2 gene and the probability to recurrent spontaneous abortion (RSA) in southern Iran. MATERIALS AND METHODS: In this study, 50 aborted fetuses tissue for the study group and blood samples umbilical-cord from newborns as control group (n = 50) were collected from Shiraz-Iran (2017). The genotyping of the target point in the IGF-2 gene was performed by Real-time Polymerase Chain Reaction and analyzed through high-resolution melting (HRM) curve. RESULTS: Based on the collected data (AA genotype = reference), allele "A" frequency in aborted fetus was 51% and control 68% as well as allele G 49% and 32%, respectively. Moreover, 27 aborted embryos (54%) were heterozygous (A/G) (OR = 3.274, 95% CI = 1.015-10.561, p = 0.04), while 18 cases (36%) in control sample showed heterozygosity. Considering the phenotypic status, the G allele had a dominant effect on the incidence of RSA (p = 0.008, OR = 3.167). CONCLUSION: Based on the present study, the risk of abortion due to loss of heterozygosity or quantitative decline of the IGF-2 is about three-fold in the southern Iran.

A novel stop-gain mutation in DPYS gene causing Dihidropyrimidinase deficiency, a case report.

BACKGROUND: Dihidropyrimidinase (DHP) deficiency is an inherited inborn error of pyrimidine metabolism with a variable clinical presentation and even asymptomatic subjects. Dihydropyrimidinase is encoded by the DPYS gene, thus pathogenic mutations in this gene can cause DHP deficiency. To date, several variations in the DPYS gene have been reported but only 23 of them have been confirmed to be pathogenic. Therefore, the biochemical, clinical and genetic aspects of this disease are still unclear. CASE PRESENTATION: Here, we report a 22-year-old woman with DHP deficiency. To identify the genetic cause of DHP deficiency in this patient, Whole Exome Sequencing (WES) was performed, which revealed a novel homozygote stop gain mutation (NM_001385: Exon 9, c.1501 A > T, p.K501X) in the DPYS gene. Sanger sequencing was carried out on proband and other family members in order to confirm the identified mutation. According to the homozygote genotype of the patient and heterozygote genotype of her parents, the autosomal recessive pattern of inheritance was confirmed. In addition, bioinformatics analysis of the identified variant using Mutation Taster and T-Coffee Multiple Sequence Alignment showed the pathogenicity of mutation. Moreover, mRNA expression level of DPYS gene in the proband's liver biopsy showed about 6-fold reduction compared to control, which strongly suggested the pathogenicity of the identified mutation. CONCLUSIONS: This study identified a novel pathogenic stop gain mutation in DPYS gene in a DHP deficient patient. Our findings can improve the knowledge about the genetic basis of the disease and also provide information for accurate genetic counseling for the families at risk of these types of disorders.

Clinical and molecular characterization of a patient with mitochondrial Neurogastrointestinal Encephalomyopathy.

BACKGROUND: Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) is a rare autosomal recessive disorder caused by mutations in TYMP gene, encoding nuclear thymidine phosphorylase (TP). MNGIE mainly presents with gastrointestinal symptoms and is mostly misdiagnosed in many patients as malabsorption syndrome, inflammatory bowel disease, anorexia nervosa, and intestinal pseudo-obstruction. Up to date, more than 80 pathogenic and likely pathogenic mutations associated with the disease have been reported in patients from a wide range of ethnicities. The objective of this study was to investigate the underlying genetic abnormalities in a 25-year-old woman affected with MNGIE. CASE PRESENTATION: The patient was a 25-year-old female referred to our center with the chief complaint of severe abdominal pain and diarrhea for 2 years that had worsened from 2 months prior to admission. The clinical and para-clinical findings were in favor of mitochondrial neurogastrointestinal encephalomyopathy syndrome. Subsequent genetic studies revealed a novel, private, homozygous nonsense mutation in TYMP gene (c. 1013 C > A, p.S338X). Sanger sequencing confirmed the new mutation in the proband. Multiple sequence alignment showed high conservation of amino acids of this protein across different species. CONCLUSION: The detected new nonsense mutation in the TYMP gene would be very important for genetic counseling and subsequent early diagnosis and initiation of proper therapy. This novel pathogenic variant would help us establish future genotype-phenotype correlations and identify different pathways related to this disorder.

Generalized exfoliative skin rash as an early predictor of supratherapeutic voriconazole trough levels in a leukemic child: A case report.

BACKGROUND AND PURPOSE: Skin rashes, mostly seen in children and adolescents, are considered among the most common side effects of azole antifungals. Although therapeutic concentrations of voriconazole (VCZ) have been documented for infected skin, there is no evidence specifying whether specific dermatologic side effects could predict high VCZ serum concentration, especially in high-risk leukemic children. CASE REPORT: Herein, we report a unique skin side effect of VCZ in a 5-year-old boy with T-cell acute lymphoblastic leukemia (ALL) referred to Amir Medical Oncology Center in Shiraz, Iran. The patient experienced erythroderma and macular rashes shortly after VCZ consumption, leading to generalized exfoliative skin rashes. Concurrent to these skin manifestations, VCZ serum concentration reached the supratherapeutic levels despite the recommended VCZ doses. As a result, VCZ was withheld, and the patient was treated with caspofungin. The lesions were resolved gradually within 2 weeks, and the patient successfully completed his treatment course with caspofungin. CONCLUSION: The unique case presented in this study emphasizes the need for a high index of suspicion for VCZ toxicity in any patient with atypical dermatologic manifestations, especially generalized exfoliative skin rashes. Based on this report, VCZ supratherapeutic concentration could be predicted early in the course of treatment. Additional therapeutic dose monitoring should be considered to establish a confirmatory diagnosis. It is required to further investigate the toxic effect of high VCZ concentration on the skin epithelium.

A Novel TTC19 Mutation in a Patient With Neurological, Psychological, and Gastrointestinal Impairment.

Mitochondrial complex III deficiency nuclear type 2 is an autosomal-recessive disorder caused by mutations in TTC19 gene. TTC19 is involved in the preservation of mitochondrial complex III, which is responsible for transfer of electrons from reduced coenzyme Q to cytochrome C and thus, contributes to the formation of electrochemical potential and subsequent ATP generation. Mutations in TTC19 have been found to be associated with a wide range of neurological and psychological manifestations. Herein, we report on a 15-year-old boy born from first-degree cousin parents, who initially presented with psychiatric symptoms. He subsequently developed progressive ataxia, spastic paraparesis with involvement of caudate bodies and lentiform nuclei with cerebellar atrophy. Eventually, the patient developed gastrointestinal involvement. Using whole-exome sequencing (WES), we identified a novel homozygous frameshift mutation in the TTC19 gene in the patient (NM_017775.3, c.581delG: p.Arg194Asnfs*16). Advanced genetic sequencing technologies developed in recent years have not only facilitated identification of novel disease genes, but also allowed revelations about novel phenotypes associated with mutations in the genes already linked with other clinical features. Our findings expanded the clinical features of TTC19 mutation to potentially include gastrointestinal involvement. Further functional studies are needed to elucidate the underlying pathophysiological mechanisms.

The association of Q472H variant in the KDR gene with recurrent pregnancy loss in Southern Iran: A case-control study.

BACKGROUND: Recurrent spontaneous abortion (RSA) often remains unclear and can be burden for the patient and time consuming for clinician. RSA may initiates from a genetic or non-genetic factors. It is well known that the quality of placental circulation is critical for implantation and embryo development. Because of angiogenic effects of VEGF-KDR pathway on placenta, the genes involved in this pathway (the KDR or VEGFR genes) are thought to be linked with RSA. OBJECTIVE: The aim of this study was to investigate the relationship between Gln472His (A/T) polymorphism of the KDR gene with RSAs in southern Iran. MATERIALS AND METHODS: In this case-control study, 50 aborted embryonic tissue obtained from fetuses and 50 umbilical cord blood of newborn babies were studied. Fetal sample from mothers with history of at least two consecutive miscarriages and controls from mothers who had at least one full-term infants born were taken. Genomic DNA was extracted by using PureLink genomic DNA kit (Life Technologies, CA). The Rotor-Gene Q real-Time PCR machine and High-resolution melting curve analysis (HRM) technique were used for genotyping. RESULTS: Based on the AA genotype as reference, it is shown that the T allele (OR = 2.447, 95% CI = 1.095-5.468, p = 0.029) as well as AT heterozygote genotype was significantly associated with an increased risk of miscarriage (OR = 2.824, 95% CI = 1.210-6.673, p = 0.016). CONCLUSION: A positive correlation between Q472H polymorphism of the KDR gene and RSA may be the cause in southern Iran.

Truncating Mutations in UBAP1 Cause Hereditary Spastic Paraplegia.

The diagnostic gap for rare neurodegenerative diseases is still considerable, despite continuous advances in gene identification. Many novel Mendelian genes have only been identified in a few families worldwide. Here we report the identification of an autosomal-dominant gene for hereditary spastic paraplegia (HSP) in 10 families that are of diverse geographic origin and whose affected members all carry unique truncating changes in a circumscript region of UBAP1 (ubiquitin-associated protein 1). HSP is a neurodegenerative disease characterized by progressive lower-limb spasticity and weakness, as well as frequent bladder dysfunction. At least 40% of affected persons are currently undiagnosed after exome sequencing. We identified pathological truncating variants in UBAP1 in affected persons from Iran, USA, Germany, Canada, Spain, and Bulgarian Roma. The genetic support ranges from linkage in the largest family (LOD = 8.3) to three confirmed de novo mutations. We show that mRNA in the fibroblasts of affected individuals escapes nonsense-mediated decay and thus leads to the expression of truncated proteins; in addition, concentrations of the full-length protein are reduced in comparison to those in controls. This suggests either a dominant-negative effect or haploinsufficiency. UBAP1 links endosomal trafficking to the ubiquitination machinery pathways that have been previously implicated in HSPs, and UBAP1 provides a bridge toward a more unified pathophysiology.

The toxicity and therapeutic effects of single-and multi-wall carbon nanotubes on mice breast cancer.

Herein, we have investigated the toxicity of SWCNTs and MWCNTs in vitro and in vivo, and assessed their therapeutic effects on a typical animal model of breast cancer in order to obtain: first, the cytotoxicity effects of CNTs on MC4L2 cell and mice, second the impact of CNTs on ablation of breast tumor. CNTs especially SWCNTs were toxic to organs and induced death at high dosages. In this case, some of the liver cells showed a relative shrinkage which was also confirmed by Annexin test in MC4L2 cells. Moreover, CNTs decreased the tumor volume. BCL2 gene was down-regulated, and BAX and Caspase-3 were also up-regulated in the treated groups with CNTs. As a result, CNTs especially MWCNT in lower dosages can be used as a promising drug delivery vehicle for targeted therapy of abnormal cells in breast cancer.

Pharmacogenetic variation of SLC47A1 gene and metformin response in type2 diabetes patients.

Type 2 diabetes mellitus is a worldwide epidemic disorder with considerable health and economic consequences. Metformin is one of the most commonly prescribed oral antidiabetic drugs. Pharmacogenetic studies showed that variants in genes related to the pharmacokinetics of metformin were associated with glucose-lowering effect of metformin. The aim of this study was to evaluate pharmacogenetic variation in SLC47A1 (rs2289669) and metformin response in type 2 diabetes patients. Seventy one patients with type 2 diabetes were included in the study. The genotypes were determined by Tetra-ARMS-PCR method. There was a significant association between the study polymorphism and the response to metformin treatment with the highest HbA1C reduction in AG genotype. In the dominant model for A allele (AA+AG vs GG), patients with A allele had highest HbA1C reduction in response to metformin.

MRI Phenotyping of COL9A2/Trp2 and COL9A3/Trp3 Alleles in Lumbar Disc Disease: A Case-control Study in South-Western Iranian Population Reveals a Significant Trp3-Disease Association in Males.

STUDY DESIGN: A case-control study of the Trp2/3 alleles of COL9A2/3 genes and their correlation with occurrence of Lumbar disc disease (DDD) as phenotyped by magnetic resonance imaging. OBJECTIVE: To establish a better understanding of relationship between presence of said alleles and occurrence of DDD in South-Western Iranian population. SUMMARY OF BACKGROUND DATA: A number of genetic predisposing factors have been identified in elevating the risk of developing DDD. Specifically, the Trp2 and Trp3 alleles of COL9A2 and COL9A3 genes have been suggested as DDD risk variants. METHODS: A total of 108 patients (mean age = 41±11.8 yrs, range = 20-66 yrs) with 57 controls (mean age = 35±10.0 yrs, range = 20-58 yrs) participated in the study. The frequency of G/A polymorphism in COL9A2 gene on location 326 on chromosome 1 and G/A/C/ or T polymorphism in 103 location of COL9A3 gene on chromosome 20 was assessed using a PCR short-primer technique. Outcome measure was defined as presence of DDD on MRI. Odds ratios (OR) and 95% confidence intervals (CI) were used to assess the likelihood of DDD given occurrence of Trp2(3). RESULTS: Each allele was present in both patients and controls. The Trp2 allele was positive in 28.5% of individuals (31.5% of patients; 22.8% of controls), OR 1.55 (0.71-3.56). The Trp3 allele, the frequency was 23.6% in all patients (26.9% patients; 17.5% controls), OR 1.72 (0.73-4.33). We observed a 5.8-fold increase in the odds of DDD in males when the Trp3 allele was present, OR 5.83 (1.09-9.98), P = 0.0273. CONCLUSION: Both Trp2 and Trp3 alleles occurred more frequently compared with other studied ethnicities. The sampled Iranian population exhibited a similar Trp2 frequency to a Southern Chinese population, and Trp3 occurrence to Finnish and Greek population. We found that male patient were much more likely to develop DDD when Trp 3 was present. LEVEL OF EVIDENCE: N/A.

NPHS2 gene in steroid-resistant nephrotic syndrome: prevalence, clinical course, and mutational spectrum in South-West Iranian children.

INTRODUCTION: Mutations in podocin (NPHS2) gene have the key role in the pathogenesis of steroid-resistant nephrotic syndrome (SRNS) in children, but data is scarce regarding their prevalence and natural course among different all ethnic groups. This study was aimed to demonstrate the spectrum of NPHS2 mutations in children with SRNS and to compare the clinical course of disease in patients with and without mutation. MATERIALS AND METHODS: All 8 exons of NPHS2 were sequenced in 99 children, including 49 with SRNS and 50 with steroid-sensitive nephrotic syndrome (control group) by DNA sequencing. RESULTS: The prevalence rates of NPHS2 gene mutation among children with SRNS and SSNS were 31% and 4%, respectively. The prevalence rates of mutation among familial and sporadic forms were 57% and 26%, respectively. Thirty-three percent of the children experienced recurrence of primary disease after kidney transplantation, none of whom had a mutation. The clinical response to treatment was poorer in children with mutation in comparison with patients without mutation (12% versus 32%, respectively; odds ratio, 3.29, 95% confidence interval, 0.40 to 25.64). Patients with and without mutation could not be differentiated by demographic and histological features, glomerular filtration rate at onset, hypertension, progression to end-stage renal disease, and proteinuria. CONCLUSIONS: Mutations of NPHS2 gene are frequent among Iranian children with SRNS. Regarding similar clinical features in patients with and without mutation and poor response to pharmacotherapy in patients with mutation, a molecular approach might be necessary for different treatment plans and prediction of prognosis.

An MTHFR variant, plasma homocysteine levels and late-onset coronary artery disease in subjects from southern Iran.

There have been many controversial debates on the role of Hyperhomocysteinaemia (HHcy) as an independent risk factor for Coronary Artery Disease (CAD) during recent years. Furthermore, an alanine/valine (Ala/Val) gene polymorphism at 222nd amino acid of 5,10-methylenetetrahydrofolate reductase (MTHFR) has been considered as a factor that could render this enzyme thermolabile and less active which in turn may yield a subsequent increase in plasma total homocysteine (tHcy) levels. To assess whether this polymorphism is associated with increased risk of CAD and plasma levels of tHcy in a population from southern Iran, a total of 457 patients with angiographically documented multi-vessel CAD were compared with a control group comprised of 371 subjects with <30% stenosis in all major vessels. Nevertheless our results failed to admit a significant difference between CAD individuals and control subjects for Ala/Val polymorphism and plasma Hcy concentrations. However, plasma Hcy concentrations were significantly higher in individuals with Val/Val genotype than subjects with Ala/Ala genotype, but it didn't show a significant association with CAD in our population. Moreover, as the multiple linear regression analysis indicated, smoking habit, folate levels and the MTHFR Val/Val genotype were the only major predictors of tHcy concentrations in the current investigation.

5,10-methylene tetrahydrofolate reductase C677T gene polymorphism, homocysteine concentration and the extent of premature coronary artery disease in southern Iran.

Elevated level of plasma homocysteine (Hcy) has been identified as an independent risk factor for coronary artery disease (CAD). Furthermore, numerous studies have documented the influences of a common polymorphism (C677T) of methylenetetrahydrofolate reductase (MTHFR) on homocysteine levels. However the relationship between this mutation and cardiovascular diseases (CVD) has remained as a controversial issue. The present study was undertaken to investigate the relationship between C677T polymorphism of MTHFR gene, plasma total Hcy levels and the number of affected vessels as a criterion for the extent of CAD. MTHFR genotypes and plasma homocysteine (HCY) concentrations were examined in 231 patients and 300 healthy subjects who underwent diagnostic coronary angiography. A multiple linear regression analysis was performed to identify the predictors of Hcy levels whereas logistic regression model was built to determine the association of Hcy quartiles with the risk of CAD adjusted for risk factors. The prevalence of MTHFR genotypes was similar between CAD patients and non-CAD individuals while the geometric mean of Hcy values was significantly higher in patient group (14.13 ± 4.11 µmol/l) than in control group (10.19 ± 3.52 µmol/l) (P < 0.001). Moreover, unlike the MTHFR polymorphism, Hcy concentration increased with increasing number of stenosed vessels and the CAD risk increased about 2 folds in the top two Hcy quartiles (≥ 17.03 and 13.20-17.02 µmol/l) compared with the lowest quartile (≤ 9.92 µmol/l) after controlling for conventional risk factors (P<0.001 for both). Our data suggest that hyperhomocysteinaemia (HHcy) is significantly associated to CAD risk increase as well as to the extent of coronary atherosclerosis.

Lack of association between Ser(413)/Cys polymorphism of plasminogen activator inhibitor type 2 (PAI-2) and premature coronary atherosclerotic disease.

Plasminogen activator inhibitor type-2 (PAI-2) is a serine protease inhibitor of the fibrinolytic system produced predominantly by the macrophages and monocytes. It has been demonstrated that fibrinolysis regulation has a great importance in the pathogenesis of atherosclerotic plaques. Thus in the current investigation, we sought to determine whether Ser(413)/Cys polymorphism (rs6104) of PAI-2 gene could be associated with atherosclerosis and cardiovascular risk factors. Ser(413)/Cys polymorphism was determined by PCR-RFLP technique using Mwo I restriction enzyme for 184 men under 50 years of age and 216 women less than 55 years of age who underwent diagnostic coronary angiography. Data on the history of familial myocardial infarction or other heart diseases, hypertension, and smoking habit were collected by a simple questionnaire. Fasting levels of blood sugar, triglycerides, total cholesterol, low-density lipoprotein and high-density lipoprotein cholesterol levels were also measured by enzymatic methods. Frequencies of the Ser(413) and Cys(413) alleles were 0.760 and 0.240 in the whole population, respectively. The PAI-2 gene variant analyzed was not significantly associated with either the prevalence of premature CAD or the classical risk factors of CAD development such as diabetes, serum cholesterol, triglycerides, low-density lipoprotein and high-density lipoprotein cholesterol, body mass index, hypertension, familial history of heart dysfunction or smoking.