Identification of a Novel Stop Loss Mutation in P2RX2 Gene in an Iranian Family with Autosomal Nonsyndromic Hearing Loss

Background: Hearing loss, a congenital genetic disorder in human, is difficult to diagnose. Whole exome sequencing is a powerful approach for ethiological disgnosis of such disorders. Methods: One Iranian family with two patients were attented in the study. Sequencing of known non-syndromic hearing loss genes was carried out to recognize the genetic causes of HL. Results: Molecular analyses identified a novel stop loss mutation, c.1048T>G (p.Term350Glu), whitin the P2RX2 gene, causing a termination-site modification.This event would lead to continued translation into the 3' UTR of the gene, which in turn may result in a longer protein product. The mutation was segregating with the disease phenotype and predicted to be pathogenic by bioinformatic tools. Conclusion: This study is the first Iranian case report of a diagnosis of autosomal dominant nonsyndromic hearing loss (ADNSHL) caused by P2RX2 mutation. The recognition of other causative mutations in P2RX2 gene more supports the probable function of this gene in causing ADNSHL.

The First Comprehensive Cohort of the Duchenne Muscular Dystrophy in Iranian Population: Mutation Spectrum of 314 Patients and Identifying Two Novel Nonsense Mutations.

Mutations in the dystrophin gene could cause Duchenne muscular dystrophy (DMD), which is the most common muscular disorder in pediatrics. Considering the growing evidence on appropriateness of gene therapies for DMD, precise genetic diagnosis seems essential. Hence, we conducted a study to determine mutational patterns in Iranian children with DMD. To detect all probable large mutations in the dystrophin gene, 314 DMD patients were evaluated using the multiplex ligation-dependent probe amplification (MLPA). Subjects who were MLPA-negative underwent the next generation sequencing (NGS) to identify potential point mutations. MLPA detected deletions (79.93%) and duplications (5.41%) along the dystrophin gene of 268 patients. Distribution of large mutations was heterogeneous and followed hotspot pattern throughout the gene. From 46 patients who were MLPA-negative, 43 exhibited point mutations including nonsense in 7.64%, frameshifts in 4.77%, splicing in 0.96%, and missense variations in 0.32% of participants. Most of the point mutations were located between exons 19 and 40. In three patients (1%), no mutation was found using either MLPA or NGS. Two subjects had novel nonsense mutations (L1675X and E1199X) in their dystrophin gene, which were considered as the possible reason for elimination of major domains of the gene. The results of this study provided invaluable information regarding the distribution of various large and small mutations in Iranian individuals with DMD. Besides, the novel nonsense mutations L1675X and E1199X were identified within the highly conserved residues, leading to elimination of significant domains of the dystrophin gene.

Cinnarizine and sodium valproate as the preventive agents of pediatric migraine: A randomized double-blind placebo-controlled trial.

BACKGROUND: Few migraine preventive agents have been assessed in a pediatric population. We evaluated the safety and efficacy of cinnarizine and sodium valproate for migraine prophylaxis in children and adolescents. METHODS: We carried out a randomized double-blind placebo-controlled trial in the Children's Medical Center and Sina hospital, Tehran, Iran. Eligible participants were randomly assigned in 1:1:1 ratio via interactive web response system to receive either cinnarizine, sodium valproate, or placebo. The primary endpoints were the mean change in frequency and intensity of migraine attacks from baseline to the last 4 weeks of trial. The secondary endpoint was the efficacy of each drug in the prevention of migraine. The drug was considered effective if it decreased migraine frequency by more than 50% in the double-blind phase compared with the baseline. Safety endpoint was adverse effects that were reported by children or their parents. RESULTS: A total of 158 children participated. The frequency of migraine attacks significantly reduced compared to baseline in cinnarizine (difference: -8.0; 95% confidence interval (CI): -9.3 to -6.6), sodium valproate (difference: -8.3; 95% confidence interval: -9.3 to -7.2), and placebo (difference: -4.4; 95% confidence interval: -5.4 to -3.4) arms. The decrease was statistically greater in cinnarizine (difference: -3.6; 95% confidence interval: -5.5 to -1.6) and sodium valproate (difference: -3.9; 95% confidence interval: -5.8 to -1.9) arms, compared to placebo group. Children in all groups had significant reduction in intensity of episodes compared to baseline (cinnarizine: -4.6; 95% confidence interval: -5.2 to -4.0; sodium valproate: -4.0; 95% confidence interval: -4.8 to -3.3; placebo: -2.6; 95% confidence interval: -3.4 to -1.8). The decrease was statistically greater in cinnarizine (difference: -2.0; 95% confidence interval: -3.2 to -0.8) and sodium valproate (difference: -1.5; 95% confidence interval: -2.7 to -0.3) arms, compared to the placebo group. Seventy-one percent of individuals in the cinnarizine group, 66% of cases in the sodium valproate group, and 42% of people in the placebo arm reported more than 50% reduction in episodes at the end of the trial. The odds ratio for >50% responder rate was 3.5 (98.3% confidence interval: 1.3 to 9.3) for cinnarizine versus placebo and 2.7 (98.3% confidence interval: 1.0 to 6.9) for sodium valproate versus placebo. Nine individuals reported adverse effects (three in cinnarizine, five in sodium valproate, and one in the placebo group) and one case in the sodium valproate group discontinued the therapy due to severe sedation. CONCLUSION: Cinnarizine and sodium valproate could be useful in migraine prophylaxis in children and adolescents. Trial registration: IRCT201206306907N4.

Genotype-Phenotype Correlations in Charcot-Marie-Tooth Disease Due to MTMR2 Mutations and Implications in Membrane Trafficking.

Charcot-Marie-Tooth type 4 (CMT4) is an autosomal recessive severe form of neuropathy with genetic heterogeneity. CMT4B1 is caused by mutations in the myotubularin-related 2 (MTMR2) gene and as a member of the myotubularin family, the MTMR2 protein is crucial for the modulation of membrane trafficking. To enable future clinical trials, we performed a detailed review of the published cases with MTMR2 mutations and describe four novel cases identified through whole-exome sequencing (WES). The four unrelated families harbor novel homozygous mutations in MTMR2 (NM_016156, Family 1: c.1490dupC; p.Phe498IlefsTer2; Family 2: c.1479+1G>A; Family 3: c.1090C>T; p.Arg364Ter; Family 4: c.883C>T; p.Arg295Ter) and present with CMT4B1-related severe early-onset motor and sensory neuropathy, generalized muscle atrophy, facial and bulbar weakness, and pes cavus deformity. The clinical description of the new mutations reported here overlap with previously reported CMT4B1 phenotypes caused by mutations in the phosphatase domain of MTMR2, suggesting that nonsense MTMR2 mutations, which are predicted to result in loss or disruption of the phosphatase domain, are associated with a severe phenotype and loss of independent ambulation by the early twenties. Whereas the few reported missense mutations and also those truncating mutations occurring at the C-terminus after the phosphatase domain cause a rather mild phenotype and patients were still ambulatory above the age 30 years. Charcot-Marie-Tooth neuropathy and Centronuclear Myopathy causing mutations have been shown to occur in proteins involved in membrane remodeling and trafficking pathway mediated by phosphoinositides. Earlier studies have showing the rescue of MTM1 myopathy by MTMR2 overexpression, emphasize the importance of maintaining the phosphoinositides equilibrium and highlight a potential compensatory mechanism amongst members of this pathway. This proved that the regulation of expression of these proteins involved in the membrane remodeling pathway may compensate each other's loss- or gain-of-function mutations by restoring the phosphoinositides equilibrium. This provides a potential therapeutic strategy for neuromuscular diseases resulting from mutations in the membrane remodeling pathway.

Serum Total Antioxidant Capacity of Epileptic Children before and after Monotherapy with Sodium Valproate, Carbamazepine, and Phenobarbital.

OBJECTIVES: This case-control study was carried out to compare serum total antioxidant capacity (TAC) in the newly diagnosed children with epilepsy and that of a control group of healthy children at the same age and probable effects of antiepileptic drugs (AEDs) prescription on it. MATERIALS & METHODS: Overall, 130 participants (65 in each group) aged between 1 and 17 yr old were enrolled. The study was conducted in Children's Medical Center, the Pediatrics Center of Excellence, Tehran, Iran in 2010. Serum TAC test was done for both control and patients group before AED therapy and after 3 months of monotherapy with sodium valproate, carbamazepine and phenobarbital in patients. Serum TAC values were measured based on Erel's method using an automated commercial kit. This method is based on the bleaching of the characteristic color of a more stable 2, 2'azinobis (3ethylbenzothiazoline6sulfonic acid) radical cation by antioxidants. The results were expressed in mmol Trolox equivalent/l. RESULTS: Serum TAC values were significantly lower in the patients group before drug administration [mean (SD): 1.31 (0.19) mmol/L] in comparison with the control group [mean (SD): 1.46 (0.21) mmol/L] (P<0.001). In the patient's group, no differences were found in the serum TAC before and 3 months after AED monotherapy. CONCLUSION: Reduced serum TAC and an increased vulnerability to oxidative stress should be considered as an etiologic factor in the children with epilepsy.

The quality of life in boys with Duchenne muscular dystrophy.

We conducted a study to evaluate the quality of life in boys with Duchenne muscular dystrophy aged 8-18 years, compared with that in matched healthy controls. A total of 85 boys with Duchenne muscular dystrophy aged 8-18 years and 136 age, sex and living place matched healthy controls were included in this study. Patients and one of their parents separately completed the 27-item Persian version of KIDSCREEN questionnaire (child and adolescent version and parent version). From the children's perspective, the quality of life in patients was found to be lower in two subclasses: "physical activities and health" (p < 0.001) and "friends" (p = 0.005). Parental estimation of their sick child's quality of life was significantly lower than children's own assessment in two subclasses: "physical activities and health" (p < 0.001) and "general mood and feelings" (p < 0.001). Our results indicate that boys with Duchenne muscular dystrophy have quite a satisfactory quality of life. A happier and more hopeful life can be promoted through increasing social support and improving the parental knowledge regarding their child's more positive life perspective.

The effects of classic ketogenic diet on serum lipid profile in children with refractory seizures.

More than 25 % of children with epilepsy develop refractory seizures unresponsive to both old and new generation anticonvulsants. Since such seizures have a serious negative impact on the quality of life, other treatment options are considered. The ketogenic diet is a well-known treatment for managing refractory seizures, although its mechanism of action is unknown. Studies have shown that this diet is as good as, or better than, any of the newer medications in reducing seizure frequency. However, concerns about adverse effects have been raised. We conducted an open label trial to show the effects of this diet on serum lipid profile. Thirty-three children with refractory epilepsy were treated with the ketogenic diet and were followed for 6 months. Their serum lipid profile was assessed at baseline, and at 3 and 6 months after initiating the diet. Seizure frequency was reduced in 63 % of children (no seizures in 2/33 and reduced >50 % in 19/33). However, after 6 months of administering the diet, median triglyceride was significantly increased (from 84 to 180 mg/dl, P < 0.001), median total cholesterol was significantly increased (from 180 to 285 mg/dl, P < 0.001), median serum low-density lipoprotein (LDL) was significantly increased (from 91 to 175 mg/dl, P < 0.001), and median serum high-density lipoprotein (HDL) was significantly increased (from 51 to 58 mg/dl, P < 0.001). Results of this study indicate that a classic ketogenic diet in children with refractory seizures is effective in seizure reduction, but leads to development of hypercholesterolemia and hypertriglyceridemia.

Usability of the head upright tilt test for differentiating between syncopal and seizure-like events in children.

The common diagnosis of loss of consciousness and clonic movements in children is seizure or epilepsy, but in a number of patients these symptoms could also be due to syncope. Over interpreted electroencephalography is misleading in a number of patients; therefore, in addition to a detailed and thorough history, a reliable test is needed to differentiate between these conditions. The aim of the study was to evaluate the utility of the head upright tilt test to differentiate between seizure-like events and syncope in children. A chart review descriptive study was conducted in a tertiary medical center in Ahvaz, Iran. We selected sixteen children (nine boys and seven girls) with convulsions of any type who were first diagnosed as epileptic based on the event description by their parents or caregivers to undergo the head upright tilt test. The main findings were the reproduction of previously presyncopal or syncopal symptoms in the tilted position. Fourteen children showed positive results after conducting the head upright tilt test, and their heart rates were significantly decreased compared to baseline at the onset of the syncopal or presyncopal manifestations. Systolic and diastolic blood pressures were significantly reduced in patients with positive results. In three children who initially had negative head upright tilt tests, intravenous isoproterenol was administered, and all three showed presyncopal and syncopal symptoms. The results indicate that the head upright tilt test could differentiate presyncopal and syncopal events in children who present with seizure-like movements but their history has clues for conclusive syncope.

Efficacy and safety of intramuscular midazolam versus rectal diazepam in controlling status epilepticus in children.

OBJECTIVE: The aim of this study was to evaluate the efficacy and safety of intramuscular midazolam in controlling convulsive status epilepticus in children, by comparing it with rectal diazepam. METHODS: In this randomized trial, 100 children (50 in each group) with convulsive status epilepticus aged 1 month to 16 years were enrolled and randomly assigned into two groups to receive either 0.3 mg/kg intramuscular midazolam or 0.5 mg/kg rectal diazepam. Main outcome measure was stopping of all motor activity after drug administration. Another measures were times between patient's arrival to emergency department till drug administration, between drug administration to seizure cessation, and between patient's arrival to seizure cessation. RESULTS: Both medication were effective for seizure control and no significant difference was found between successful treatments after administering the medication (P = 0.061). In the midazolam group, in 96% (48/50) of cases treatment was successful and in the diazepam group, in 94% (47/50) of cases treatment was successful. Time from arrival to administering the medication was significantly shorter in midazolam group (P = 0.017). The majority of seizures in midazolam group were stopped in less than 66 s (median) compared to 130 s (median) for diazepam group, (P < 0.001). No serious adverse effects were seen in both groups. CONCLUSION: IM midazolam is not superior but may be at least as effective as rectal diazepam for controlling of status epilepticus in children. Midazolam via IM route could be one of the choices in children with convulsive status seizures who have difficult IV access.

Sleep Inducing for EEG Recording in Children: A Comparison between Oral Midazolam and Chloral Hydrate.

OBJECTIVE: Electroencephalography (EEG) recording is a long duration procedure that needs patient's cooperation for device setup and performing the procedure. Many children lose their cooperation during this procedure. Therefore, sedation and sleep are frequently induced using a few agents as pre procedure medication in children before EEG recording. We aimed to compare the sedative effects of oral midazolam versus chloral hydrate before the procedure along with their impacts on EEG recording in children. MATERIALS & METHODS: A randomized trial was carried out to compare the sedative effects of oral midazolam versus chloral hydrate and their impacts on EEG recording in children. A total of 198 children (100 in the midazolam group and 98 in the chloral hydrate group) were enrolled in the study and randomly allocated to receive either oral moidazolam or chloral hydrate. RESULTS: Oral midazolam had superiority neither in sleep onset latency nor in sleep duration when compared to chloral hydrate. Moreover, the yield of epileptiform discharges in the chloral hydrate group was more than the midazolam group. CONCLUSION: The results of this study showed that both chloral hydrate 5% (one ml/kg) and oral midazolam (0.5 mg/kg) could be administered as a pre medication agent for EEG recording in children. However, oral midazolam at this dose had no advantage compared with chloral hydrate.

Tissue Doppler echocardiographic findings of left ventricle in children with sickle-cell anemia.

BACKGROUND: Sickle-cell disease (SCD) is an inherited hemoglobin childhood disorder, frequently complicated by pulmonary hypertension and cardiac involvement. Cardiovascular events and complications are the leading cause of mortality and morbidity in patients with SCD. Tissue Doppler imaging and the myocardial performance index (Tei index), are simple indices for the assessment of the cardiac function. The purpose of this study was to assess the left ventricular function in children with SCD. METHODS: Sixty-four patients with SCD (mean age = 11.7 ± 5.5 years) were compared with 50 age-matched healthy controls (mean age = 11.2 ± 5.20 years). Myocardial wall motion velocities at the lateral mitral annulus and the junction between the medial mitral annulus and the interventricular septum were assessed during systole (Sa), early diastole (Ea), and late diastole (Aa) through a four-chamber view using pulsed Doppler echocardiography. The ejection fraction and shortening fraction were estimated. The Tei index was estimated via tissue Doppler echocardiography. RESULTS: The results showed that Ea and Aa velocity in the mitral annulus and interventricular septum had no difference between the patients and controls (p value > 0.05), and nor was there any difference between the two groups as regards the Tei index, Ea/Aa, ejection fraction, and shortening fraction (p value > 0.05). Sa(m) wave velocity, however, had a significant difference between the two groups (p value < 0.038). CONCLUSION: The Tei index is a sensitive indicator for the cardiac function in chronic diseases and the right ventricular function in some disorders such as SCD.

Effect of anti-epileptic drugs on serum level of IgG subclasses.

OBJECTIVE: There are some controversial studies on effects of anti-epileptic drugs (AEDs) on serum IgG subclasses; however, the role of these medications is still unclear. The aim of this study was evaluation the effects of anti-epileptic drugs on serum concentration of IgG and its subclasses METHODS: Serum IgG and IgG subclasses of 61 newly diagnosed epileptic patients were measured at the beginning of monotherapy with carbamazepine, sodium valproate, and phenobarbital, and 6 months later. Measurement of IgG and its subclasses was performed using nephlometry and ELISA techniques, respectively. FINDINGS: Reduction of at least one IgG subclass was found in 6 patients 6 months after treatment with AEDs. Among 27 patients receiving carbamazepine, decrease in at least one serum IgG subclass level was found in 5 patients. Among 20 patients using sodium valproate, only one patient showed decrease in IgG2 subclass. None of the 14 patients using phenobarbital revealed significant decrease in IgG subclasses. No infection was seen in the patients with reduction of subclasses. CONCLUSION: Although in our study, children with selective IgG subclass deficiency were asymptomatic, assessment of serum immunoglobulin levels could be recommended at starting the administration of AEDs and in serial intervals afterward in epileptic patients.