Identification of novel mutations among Iranian NPC1 patients: a bioinformatics approach to predict pathogenic mutations.

BACKGROUND: Niemann-Pick disease type C (NPC) is a rare lysosomal neurovisceral storage disease caused by mutations in the NPC 1 (95%) or NPC2 (5%) genes. The products of NPC1 and NPC2 genes play considerable roles in glycolipid and cholesterol trafficking, which could consequently lead to NPC disease with variable phenotypes displaying a broad spectrum of symptoms. MATERIALS: In the present study 35 Iranian NPC unrelated patients were enrolled. These patients were first analysed by the Filipin Staining test of cholesterol deposits in cells for NPC diagnostics. Genomic DNA was extracted from the samples of peripheral blood leukocytes in EDTA following the manufacturer's protocol. All exon-intron boundaries and coding exons of the NPC1gene were amplified by polymerase chain reaction (PCR) using appropriate sets of primers. Thereafter, the products of PCR were sequenced and analysed using the NCBI database ( https://blast.ncbi.nlm.nih.gov/Blast.cgi ). The variants were reviewed by some databases including the Human Gene Mutation Database (HGMD) ( http://www.hgmd.cf.ac.uk/ac/index.php ) and ClinVar ( https://www.ncbi.nlm.nih.gov/clinvar (. Moreover, all the variants were manually classified in terms of the American College of Medical Genetics and Genomics (ACMG) guideline. RESULTS: The sequence analysis revealed 20 different variations, 10 of which are new, including one nonsense mutation (c.406C > T); three small deletions, (c.3126delC, c.2920_2923delCCTG, and c.2037delG); and six likely pathogenic missense mutations, (c.542C > A, c.1970G > A, c.1993C > G, c.2821 T > C, c.2872C > G, and c.3632 T > A). Finally, the pathogenicity of these new variants was determined using the ACMG guidelines. CONCLUSION: The present study aimed to facilitate the prenatal diagnosis of NPC patients in the future. In this regard, we identified 10 novel mutations, and verified that the majority of them occurred in six NPC1 exons (5, 8, 9, 13, 19, and 21), that should be considered with a high priority for Iranian patients' cost-effective evaluation.

Analysis of the HEXA, HEXB, ARSA, and SMPD1 Genes in 68 Iranian Patients.

Lysosomal storage diseases (LSDs) are known as genetic disorders with an overall prevalence of 1 per 7700 live births. Sphingolipidosis, which is a subgroup of LSDs, is resulted from mutations in the coding genes of specific enzymes of sphingolipid hydrolases. The current study aimed to provide additional knowledge on the genotype of sphingolipidoses disease among Iranian patients affected by the disease. In this research, we studied 68 unrelated Iranian patients diagnosed with one kind of sphingolipidoses from 2014 to 2019. Thereafter, genomic DNA was isolated from their peripheral blood leukocytes samples in EDTA in terms of the manufacturer's protocol. All the coding exons and exon-intron boundaries of the related genes were sequenced and then analyzed using the NCBI database. Finally, they were reviewed using some databases such as the Human Gene Mutation Database (HGMD) and ClinVar ( https://www.ncbi.nlm.nih.gov/clinva ). By studying 22 MLD patients, 18 different variations of the ARSA gene were found, one of which was new including, named as c.472 T > G p. (Cys158Gly). Out of 15 Sandhoff disease (SD) patients, 11 different variations of the HEXB gene were found. Correspondingly, the c.1083-2delA was not reported earlier. By investigating 21 Iranian patients with Tay-Sachs disease (TSD), one new variant was found as c.622delG. The study of 10 Niemann-Pick disease A/B (NPDA/B (patients has led to the identification of 9 different SMPD1 gene variations, among which 3 variations were novel mutations. The results of the present study can be expanded to the genotypic spectrum of Iranian patients with MLD, SD, TSD, and NPD diseases and also used to innovate more effective methods for the detection of genetic carriers as well as diagnosing and counseling of Iranian patients affected with these disorders.

An Uncommon Presentation of Mucopolysaccharidosis Type IIIb.

Mucopolysaccharidosis type III (MPS III; Sanfilippo syndrome) is a metabolic disorder characterized by a lysosomal enzyme deficiency in the catabolic pathway of heparan sulfate. The patients with mucopolysaccharidosis type III usually present with declined neurocognitive functions such as speech and hearing loss. Subtle somatic features of patients with mucopolysaccharidosis type III can lead to diagnostic delay and consequently, a greater neurocognitive deterioration may happen. Herein, we report a 9-yr-old boy referred to Loghman Hospital, Tehran, Iran, in 2018. He had developed normally up to four yr of age when his symptoms initiated with behavioral disturbances such as auditory agnosia and decreased verbal communication. Progression of his symptoms to seizure and ataxia, brain perfusion scan and electroencephalography features strongly suggested landau-Kleffner syndrome. However, results of gene sequencing analysis and high urinary glycosaminoglycan excretion confirmed mucopolysaccharidosis type III as his final diagnosis. This case strongly recommends screening for metabolic disorders such as mucopolysaccharidosis type III in the patients diagnosed as having landau-Kleffner syndrome.

Clinical, biochemical and molecular features of Iranian families with mucopolysaccharidosis: A case series.

This study aims to ascertain the genetic variants which contribute to the most common types of MPS in eleven Iranian families. Clinical and biochemical features were obtained during initial examination and patients were further investigated for genetic defects in the MPS genes. Peripheral blood samples were obtained from all family members after obtaining written informed consent. Based on the patient's clinical diagnosis, three different genetic tests including Sanger sequencing of four genes (IDUA, IDS, SGSH, and GALNS), targeted panel (10 genes) and Whole Exome Sequencing (WES) techniques were applied to identify the causative variants. A total of 12 different mutations were identified in five genes, including nine novel mutations and three previously reported missense mutations. Sanger sequencing confirmation of the identified mutations determined one case of compound heterozygous in the NAGLU gene. In this study, novel mutations in MPS related genes were identified attempting to characterize the type and subtype of the disease using molecular approaches. Results of the study positively contribute to mutation spectrum of IDUA, IDS, SGSH, NAGLU, and GALNS genes in the Iranian cohort. It may also enrich genetic counseling for rapid risk assessment and disease management.

A Novel Nonsense Mutation in PANK2 Gene in Two Patients with Pantothenate Kinase-Associated Neurodegeneration.

Pantothenate kinase- associated neurodegeneration (PKAN) syndrome is a rare autosomal recessive disorder characterized by progressive extrapyramidal dysfunction and iron accumulation in the brain and axonal spheroids in the central nervous system. It has been shown that the disorder is caused by mutations in PANK2 gene which codes for a mitochondrial enzyme participating in coenzyme A biosynthesis. Here we report two cases of classic PKAN syndrome with early onset of neurodegenerative disorder. Mutational analysis has revealed that both are homozygous for a novel nonsense mutation in PANK2 gene (c.T936A (p.C312X)). The high prevalence of consanguineous marriages in Iran raises the likelihood of occurrence of autosomal recessive disorders such as PKAN and necessitates proper premarital genetic counseling. Further research is needed to provide the data on the prevalence of PKAN and identification of common PANK2 mutations in Iranian population.

The best time for EEG recording in febrile seizure.

OBJECTIVE: Some studies suggest that detection of epileptic discharge is unusual during the first postictal week of febrile seizure and others believe that EEGs carried out on the day of the seizure are abnormal in as many as 88% of the patients. In this study, we intend to compare early and late EEG abnormalities in febrile seizure. MATERIALS & METHODS: EEG was recorded during daytime sleep, 24-48 hours (early EEG) and 2 weeks (late EEG) after the seizure in 36 children with febrile seizure (FS), aged between 3 months and 6 years. EEGs that showed generalized or focal spikes, sharp, spike wave complex, and slowing were considered as abnormal EEG. Abnormalities of the first EEG were compared with those of second EEG. RESULTS: The most common abnormal epileptiform discharges recorded in the early EEG were slow waves (27.6%) and sharp waves in late EEG (36%). Distribution of abnormalities in early and late EEG showed no significant statistical difference. CONCLUSION: The early and late EEG recording had the same results in patient with febrile seizure.

Megalencephaly-polymicrogyria-polydactyly-hydrocephalus syndrome: a case report.

This report describes a case of megalencephaly-polymicrogyria-polydactyly-hydrocephalus syndrome in a 1-year-old boy, born to healthy nonconsanguineous parents. Megalencephaly and bilateral postaxial polydactyly of upper and lower limbs were noted at birth. He had profound developmental delay and moderate hypotonia. Magnetic resonance imaging (MRI) of the brain revealed hydrocephalus, polymicrogyria in both frontal lobes and perisylvian regions, and thin corpus callosum. Array-comparative genomic hybridization was normal. The patient's clinical and radiologic findings fit the classic description of megalencephaly-polymicrogyria-polydactyly-hydrocephalus syndrome. The possible overlap between megalencephaly-polymicrogyria-polydactyly-hydrocephalus syndrome and other similar conditions is discussed.

Effects of miglustat on stabilization of neurological disorder in niemann-pick disease type C: Iranian pediatric case series.

Niemann-Pick disease type C is a rare neurodegenerative disorder with autosomal recessive inheritance that can be broadly categorized into different forms dependent on age at disease onset: pre-/perinatal, early infantile, late infantile, juvenile, and adolescent/adult. This study was conducted to define the age at onset, clinical manifestations, neuroimaging findings and response to treatment in 21 patients diagnosed with Niemann-Pick disease type C and managed in the neurology departments of hospitals in Tehran, Iran. The effects of miglustat on patient ambulation, fine and gross motor function, swallowing, hearing, speech, seizures, psychomotor development, and ocular movements were evaluated for up to 26 months of treatment. Ambulation, fine and gross motor movements, swallowing, speech, and supranuclear gaze palsy were generally stabilized during therapy, and psychomotor delay appeared to be improved in early- and late-infantile onset patients. However, miglustat had no effect on organomegaly or other systemic manifestations of the disease. Miglustat was well tolerated.

Relationship between migraine and abnormal EEG findings in children.

OBJECTIVE: Migraine is a disabling illness that causes absence from school and affects the quality of life. It has been stated that headache may represent an epileptic event. EEG abnormality is a prominent finding in children with migraine. The aim of this study was to evaluate EEG abnormalities in children with migraine. MATERIALS & METHODS: Two-hundred twenty-eight children were enrolled into the study. Evaluation and following of cases was performed by one physician, paraclinical tests were used to increase the accuracy. The study was conducted under the supervision of pediatric neurology masters and the selected cases were from different parts of the country. RESULTS: Comparing EEG abnormalities in different types of migraine revealed that there is an association between them. There was also a significant difference between EEG abnormalities in different types of aura. Migraine type was associated with the patient's age. Sleep disorders were more common in patients with a positive family history of seizure. CONCLUSION: Our study dosclosed migraine as a common problem in children with abnormalities present in approximately 20% of the patients. Migraine and abnormal EEG findings are significantly associated.

Clinical and Para clinical Manifestations of Tuberous Sclerosis: A Cross Sectional Study on 81 Pediatric Patients.

OBJECTIVE: Tuberous sclerosis complex is an autosomal dominant neurocutaneous disease that presents with dermatological, neurological, cardiac, renal and ocular symptoms. We described the variable clinical manifestations, neuroimaging findings, Age and sex distribution of tuberous sclerosis in a group of 81 patients referred to our clinic. MATERIALS & METHODS: Based on the diagnostic criteria, totally 81 tuberous sclerosis patients with sufficient data were enrolled into the study. These children were referred by child neurologists. RESULTS: The mean age of the patients was 52 months (range, 7-180 months). There were 28 girls and 53 boys. A positive familial history of TSC was seen in 29.6% of the patients. Hypo pigmented macules were the most common manifestation (82.7%). Facial angiofibroma, shagreen patches, café-au-lait lesions and seizure were observed in 32.1%, 12.3%, 7.4%. and 74.1% of the studied cases, respectively. Infantile spasm was present in the clinical course of 32.1 % of the patients. Cortical tubers were the most common MRI finding which were seen in 21 cases (25.9%). Subepandymal giant cell astrocytoma was seen in four (4.9%) patients and intracranial calcification (detected by CT scan) was observed in 18 (22.2%) of the patients. CONCLUSION: Dermatological and neurological findings were the most common symptoms in tuberous sclerosis with a significant correlation between them. Thus, careful skin examination is necessary in epileptic patients for detection of the mentioned lesions.