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.

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.

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.

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.

Detection of Hb Setif in north Iran and the question of its origin: Iranian or multiethnic?

Hb Setif is a rare type of hemoglobinopathy resulting from an aspartic acid to tyrosine substitution at codon 94 (GAC>TAC) of the α2-globin gene. In manual and automated hemoglobin (Hb) electrophoresis examination of the case, an unusual band was detected and the result of subsequent capillary electrophoresis suggested that to be Hb Setif. Carrying out polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and DNA sequencing, a typical Hb Setif mutation (GAC>TAC) was identified. The haplotype of the α cluster was + + - M PZ + - - - -. This is the first report of such a hemoglobinopathy in North Iran. Various reports of such Hb variants in Iran and countries in the Mediterranean region and North Africa, suggest that the mutation may have occurred around 6,000 years ago, prior to colonization of Aryans on the Iranian plateau.

Non-hodgkin lymphoma in a child with schimke immuno-osseous dysplasia.

Schimke immuno-osseous dysplasia is a rare autosomal recessive multisystem disorder characterized by steroid-resistant nephrotic syndrome, immunodeficiency, and spondyloepiphyseal dysplasia. Mutations in SWI/SNF2 related, matrix associated, actin dependent regulator of chromatin, subfamily a-like 1 (SMARCAL1) gene are responsible for the disease. The present report describes, for the first time, a Schimke immuno-osseous dysplasia child with SMARCAL1 missense mutation (R561H) and manifestations of intussusception secondary to Epstein-Barr virus-negative non-Hodgkin lymphoma, who expired due to septicemia following chemotherapy. The report emphasizes the necessity of more limited immunosuppressive protocols in Schimke immuno-osseous dysplasia patients with lymphoproliferative disorders.

Lower lip pits in a patient with van der Woude syndrome.

van der Woude syndrome (VWS) is a congenital malformation characterized by lower lip pits with or without cleft lip or cleft palate. It is an autosomal-dominant inherited disorder with variable expression in clinical manifestation. Microdeletion in chromosome bands 1q32-q41 and recently identified mutation in interferon regulatory factor 6 gene (IRF6) have been reported to cause VWS. We report a case of VWS with lower lip pits as its main clinical manifestation without associated cleft in lip or palate. No mutation or deletion was found in the IRF6 gene or promoter site, indicating the heterogeneity of this defect.

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.

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.

Multi centric origin of Hb D-Punjab [beta121(GH4)Glu-->Gln, GAA>CAA].

Hb D-Punjab [beta121(GH4)Glu-->Gln, GAA>CAA], common in the northern Indian province, is often unexpectedly found in other populations. To study the multi centric origin of this variant which is causing sickle cell disease in association with Hb S [beta6(A3)Glu-->Val, GAG>GTG], we have examined the haplotype of the Hb D allele in different populations. We studied 43 alleles from south Iran (Hormozgan and Fars provinces) and 14 from Holland and Belgium using high performance liquid chromatography (HPLC), capillary electrophoresis, direct sequencing and/or restriction enzyme analysis. In Iranians, four haplotypes were observed at different frequencies: haplotype I [+ - - - -,+ +] at 67.5%, subhaplotype I' [+ - - - -,- +] at 17.5%, haplotype V [- + - - +,+ +] at 10.0% and haplotype III [- + - + +,+ +] at 5.0%. All European cases were on haplotype I. The occurrence of high Hb D frequencies on a single haplotype in specific regions can be expected if we consider founder effect and genetic drift mechanisms. However, considering that haplotype I is the most common haplotype worldwide, that Hb D-Punjab is reported in different populations on different haplotypes, and that codon beta121 is a site on which six different mutations are reported, we may expect to observe Hb D-Punjab in different populations, possibly because of a relatively higher occurrence of de novo mutations, generating unexpected risk from mixtures of allochtonous Hb S and indigenous Hb D-Punjab or vice versa.

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.

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.

Prevalence of beta-thalassemia trait and glucose-6-phosphate dehydrogenase deficiency in Iranian Jews.

BACKGROUND: beta-thalassemia is the most common inherited single gene disorder worldwide, and glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common human enzyme deficiency. The goal of this study was to compare the frequency of beta-thalassemia trait and G6PD among the Moslem and Jewish populations in Shiraz, southern Iran. METHODS: We examined 201 Moslems and 187 Jewish subjects who were selected by random sampling. For diagnosis of thalassemia, complete blood count and hemoglobin electrophoresis were carried out and for G6PD deficiency, fluorescent spot test methods were used as a screening test. RESULTS: Among Moslem subjects, 14 cases (7.0%) were diagnosed as carriers of beta-thalassemia minor, whereas no carriers were detected among Jewish subjects. Seven Moslems (7%) and eight Jewish subjects (7.5%) were found to have G6PD deficiency. Among both groups the most common mutation was the Mediterranean type (563 C>T). In one Moslem subject, the detected mutation was 1003 (G>A) and in two Jewish subjects the mutations were 1376 (G>T) and G6PD A-. CONCLUSIONS: Whereas the frequency of beta-thalassemia minor among Moslems is higher than in the Jews in Shiraz, the frequency of G6PD deficiency was not significantly different in the two populations. These findings suggest that obligatory premarital beta-thalassemia screening for Jews in the community is not necessary, whereas neonatal screening for G6PD could be useful for both Jews and Moslems.

Genetic counseling in southern Iran: consanguinity and reason for referral.

Population based genetic counseling that promotes public health goals is an appropriate health care service. The genetic counseling center in Shiraz, southern Iran serves most of the clients in the region. During a 4-year period, 2,686 couples presented for genetic counseling. Data files revealed that 85% had consanguineous relationships (1.5% double first cousin, 74% first cousin, 8% second cousin, 1.5% beyond second cousin). Most prevalent reasons for referral were premarital counseling (80%), with 89% consanguinity, followed by preconception (12%), postnatal (7%), and prenatal counseling (1%). The most common abnormalities in probands or relatives were intellectual and developmental disabilities, hearing loss/impairment, and neuromuscular dystrophies. Family history of medical problem(s) and/or consanguinity was the main indication for referral in nearly every family. Premarital consanguinity poses unique challenges and opportunities. There is considerable opportunity for genetic counseling and education for couples in this population. The tradition of consanguinity, which is likely to persist in Iran, requires multidisciplinary agreement regarding the appropriate process of genetic counseling. Effective genetic counseling in Iran hinges on inclusion of data from genetic counseling services in national genomic and epidemiologic research programs.

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.