P. Ala278Val mutation might cause a pathogenic defect in HEXB folding leading to the Sandhoff disease.

Sandhoff disease is a rare neurodegenerative and autosomal recessive disorder, which is characterized by a defect in ganglioside metabolism. Also, it is caused by mutations in the HEXB gene for the ß-subunit isoform 1 of ß-N-acetyl hexosaminidase. In the present study, an Iranian 14- month -old girl with 8- month history of unsteady walking and involuntary movements was described. In this regard, biochemical testing showed some defects in the normal activity of beta-hexosaminidase protein. Following sequencing of HEXB gene, a homozygous c.833C > T mutation was identified in the patient's genome. After recognition of p.A278V, several different in silico methods were used to assess the mutant protein stability, ranging from mutation prediction methods to ligand docking. The p.A278V mutation might be disruptive because of changing the three-dimensional folding at the end of the 5th alpha helix. According to the medical prognosis, in silico and structural analyses, it was predicted to be disease cause.

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.

Repetitive Suicidal Behaviors in a Case With a New Mutation of Wolfram Syndrome: A Jump From the Gene to the Behavior.

Wolfram syndrome (WS) is a rare autosomal recessive neurodegenerative disease with variable symptoms, including neuropsychiatric manifestations. A 26-year-old man was reported with classic symptoms of WS and repetitive psychiatric hospitalizations and at least 16 suicidal attempts. The genetic study demonstrated a novel homozygous stop-codon mutation on the WFS1 gene. This special type of mutation may be related to repetitive suicidal behaviors in this case of WS. Psychological support should be a routine practice in patients with WS.

Novel bi-allelic variants expand the SPTBN4-related genetic and phenotypic spectrum.

Neurodevelopmental disorder with hypotonia, neuropathy, and deafness (NEDHND, OMIM #617519) is an autosomal recessive disease caused by homozygous or compound heterozygous variants in SPTBN4 coding for type 4 ßIV-spectrin, a non-erythrocytic member of the ß-spectrin family. Variants in SPTBN4 disrupt the cytoskeletal machinery that controls proper localization of ion channels and the function of axonal domains, thereby generating severe neurological dysfunction. We set out to analyze the genetic causes and describe the clinical spectrum of suspected cases of NEDHND. Variant screening was done by whole exome sequencing; clinical phenotypes were described according to the human phenotype ontology, and histochemical analysis was performed with disease-specific antibodies. We report four families with five patients harboring novel homozygous and compound heterozygous SPTBN4 variants, amongst them a multi-exon deletion of SPTBN4. All patients presented with the key features of NEDHND; severe muscular hypotonia, dysphagia, absent speech, gross motor, and mental retardation. Additional symptoms comprised horizontal nystagmus, epileptiform discharges in EEG without manifest seizures, and choreoathetosis. Muscle histology revealed both characteristics of myopathy and of neuropathy. This report expands the SPTBN4 variant spectrum, highlights the spectrum of morphological phenotypes of NEDHND-patients, and reveals clinical similarities between the NEDHND, non-5q SMA, and congenital myopathies.

Clinical Feature and Genetics in Rett Syndrome: A Report on Iranian Patients.

OBJECTIVES: Rett syndrome is characterized by normal development for the first 6-18 months of life followed by the loss of fine and gross motor skills and the ability to engage in social interaction. In most patients, mutations are found in methyl CpG-binding protein 2 (MECP2) gene. We investigated the relation between Rett clinical diagnosis and mutations in MECP2. MATERIALS & METHODS: Children suspected of Rett syndrome were invited to participate in this study. Twenty-three patients from the Mofid Hospital, Tehran, Iran suffered from classic Rett syndrome diagnostic criteria were enrolled in 2012. The severity of symptoms was assessed for all of them. The peripheral blood samples were collected in EDTA tubes and the genomic DNA was extracted using standard salting out method. The mutation of MEPC2 gene was studied using DNA sequencing method. RESULTS: Overall, 11(47.8%) patients had MECP2 gene mutation, while 12 cases (52.2%) had no mutations. Changes in genetics were associated with phenotypical manifestations. The most prevalent mutation was p.v288 mainly associated with partially or uncontrolled seizures. CONCLUSION: For the first time, we studies the Rett syndrome in terms of clinical manifestations and genetic changes in Iran.

Genetic Analysis of MECP2 Gene in Iranian Patients with Rett Syndrome.

OBJECTIVES: Rett syndrome is an X linked dominant neurodevelopmental disorder which almost exclusively affects females. The syndrome is usually caused by mutations in MECP2 gene, which is a nuclear protein that selectively binds CpG dinucleotides in the genome. MATERIALS & METHODS: To provide further insights into the distribution of mutations in MECP2 gene, we investigated 24 females with clinical characters of Rett syndrome referred to Alzahra University Hospital in Isfahan, Iran during 2015-2017. We sequenced the entire MECP2 coding region and splice sites for detection of point mutations in this gene. Freely available programs including JALVIEW, SIFT, and PolyPhen were used to find out the damaging effects of unknown mutations. RESULTS: Direct sequencing revealed MECP2 mutations in 13 of the 24 patients. We identified in 13 patients, 10 different mutations in MECP2 gene. Three of these mutations have not been reported elsewhere and are most likely pathogenic. CONCLUSION: Defects in MECP2 gene play an important role in pathogenesis of Rett syndrome. Mutations in MECP2 gene can be found in the majority of Iranian RTT patients. We failed to identify mutations in MECP2 gene in 46% of our patients. For these patients, further molecular analysis might be necessary.

A novel homozygous variation in the PANK2 gene in two Persian siblings with atypical pantothenate kinase associated neurodegeneration.

Pantothenate Kinase-associated Neurodegeneration (PKAN) is an autosomal recessive disorder that is caused by variation in pantothenate kinase-2 gene (PANK2) gene on chromosome 20. The common presentation of this disease includes progressive dystonia, Parkinsonism, retinopathy, cognitive impairment, and spasticity. The typical magnetic resonance imaging finding is eye of the tiger sign in globus pallidus and not pathogenic and not found in all patients. In the present study, we describe two siblings who have a novel variation of the PANK2 gene. These patients with the same genotype, have different ages at the onset of disease and also the various severity of the disease. The description of these cases helps to understand this disease, its symptoms, pathogenesis, and its treatment.

WISP3 mutation associated with pseudorheumatoid dysplasia.

Progressive pseudorheumatoid dysplasia (PPD) is a skeletal dysplasia characterized by predominant involvement of articular cartilage with progressive joint stiffness. Here we report genetic characterization of a consanguineous family segregating an uncharacterized from of skeletal dysplasia. Whole-exome sequencing of four affected siblings and their parents identified a loss-of-function homozygous mutation in the WISP3 gene, leading to diagnosis of PPD in the affected individuals. The identified variant (Chr6: 112382301; WISP3:c.156C>A p.Cys52*) is rare and predicted to cause premature termination of the WISP3 protein.

Four novel ARSA gene mutations with pathogenic impacts on metachromatic leukodystrophy: a bioinformatics approach to predict pathogenic mutations.

Metachromatic leukodystrophy (MLD) disorder is a rare lysosomal storage disorder that leads to severe neurological symptoms and an early death. MLD occurs due to the deficiency of enzyme arylsulfatase A (ARSA) in leukocytes, and patients with MLD excrete sulfatide in their urine. In this study, the ARSA gene in 12 non-consanguineous MLD patients and 40 healthy individuals was examined using polymerase chain reaction sequencing. Furthermore, the structural and functional effects of new mutations on ARSA were analyzed using SIFT (sorting intolerant from tolerant), I-Mutant 2, and PolyPhen bioinformatics software. Here, 4 new pathogenic homozygous mutations c.585G>T, c.661T>A, c.849C>G, and c.911A>G were detected. The consequence of this study has extended the genotypic spectrum of MLD patients, paving way to a more effective method for carrier detection and genetic counseling.

Identification of a new mutation in an Iranian family with hereditary multiple osteochondromas.

BACKGROUND: Hereditary multiple osteochondromas (HMO), previously named hereditary multiple exostoses (HME), is an autosomal dominant skeletal disorder characterized by the growth of multiple osteochondromas and is associated with bony deformity, skeletal growth reduction, nerve compression, restriction of joint motion, and premature osteoarthrosis. HMO is genetically heterogeneous, localized on at least three chromosomal loci including 8q24.1 (EXT1), 11p11-p13 (EXT2), and 19p (EXT3). The median age of diagnosis is 3 years; almost all affected individuals are diagnosed by age 12. The risk for malignant degeneration to osteochondrosarcoma increases with age, although the lifetime risk of malignant degeneration is low (~1%). METHODS AND RESULTS: This study was performed on an Iranian family with nine affected individuals from three consecutive generations. Here, the proband was an affected woman who received genetic counseling prior to pregnancy. All exons of the three genes were examined in the proband using polymerase chain reaction and sequencing methods (the last member of this family is a male with severe deformities and lesions, especially around his large joints). Exon 4 of EXT1 (c.1235 G>A) was changed in affected individuals. This mutation alters tryptophan to a premature stop codon on amino acid position 412 (p.Trp412x). CONCLUSION: The outcome of this study has extended the genotypic spectrum of Iranian patients with HMO, revealing a way for improving detection and genetic counseling in carriers.

Late-onset pompe disease in Iran: A clinical and genetic report.

INTRODUCTION: Pompe disease is characterized by absence or deficiency of acid α-glucosidase, and several causative mutations are known. In this study we report clinical and laboratory data in Iranian patients with late-onset Pompe disease (LOPD), focusing on population-specific mutations. METHODS: Clinical and laboratory data of 14 patients from 10 families with the diagnosis of LOPD were recorded. All had reduced enzyme activity on dried blood spot (DBS) analysis. Genetic investigation was performed to identify the underlying mutations. RESULTS: The age of onset ranged from <2 to 38 years. The clinical presentations were heterogeneous. Two siblings presented with foot drop. The most common mutation was c.(-32-13T>G). There were 4 novel mutations: c.(2040 + 2dup); c.(1650delG); c.(1837T>G); and c.(2596delG). CONCLUSION: This is a comprehensive report of LOPD in Iranian patients. Distinct phenotypic and genotypic features in this population are highlighted. Muscle Nerve 55: 835-840, 2017.

Expanding the clinical and mutational spectrum of the Ehlers-Danlos syndrome, dermatosparaxis type.

PURPOSE: The Ehlers-Danlos syndrome (EDS), dermatosparaxis type, is a recessively inherited connective tissue disorder caused by deficient activity of ADAMTS-2, an enzyme that cleaves the aminoterminal propeptide domain of types I, II, and III procollagen. Only 10 EDS dermatosparaxis patients have been reported, all presenting a recognizable phenotype with characteristic facial gestalt, extreme skin fragility and laxity, excessive bruising, and sometimes major complications due to visceral and vascular fragility. METHODS: We report on five new EDS dermatosparaxis patients and provide a comprehensive overview of the current knowledge of the natural history of this condition. RESULTS: We identified three novel homozygous loss-of-function mutations (c.2927_2928delCT, p.(Pro976Argfs*42); c.669_670dupG, p.(Pro224Argfs*24); and c.2751-2A>T) and one compound heterozygous mutation (c.2T>C, p.? and c.884_887delTGAA, p.(Met295Thrfs26*)) in ADAMTS2 in five patients from four unrelated families. Three of these displayed a phenotype that was strikingly milder than that of previously reported patients. CONCLUSION: This study expands the clinical and molecular spectrum of the dermatosparaxis type of EDS to include a milder phenotypic variant and stresses the importance of good clinical criteria. To address this, we propose an updated set of criteria that accurately captures the multisystemic nature of the dermatosparaxis type of EDS.Genet Med 18 9, 882-891.

A Novel Mutation in Aspartoacylase Gene; Canavan Disease.

Objective Canavan disease (CD) is a type of vacuolating leukodystrophy with autosomal recessive inheritance. Aspartoacylase deficiency results in decrease of myelin biosynthesis, dysmyelination and brain edema. Although CD is a very common in Ashkenazi Jews patients, several cases have been reported from non-Jewish population. This report is based on a homozygous C.202G>A mutation in the ASPA gene identified from an Iranian patient. To our knowledge, this type of mutation has not been reported in non-Jewish population in the literature.

Measuring Serum Level of Ionized Magnesium in Patients with Migraine.

OBJECTIVE: Migraine is known as one of the most disabling types of headache. Among the variety of theories to explain mechanism of migraine, role of serum magnesium is of great importance. Serum magnesium, as a pathogenesis factor, was considerably lower in patients with migraine. We established this study to see if serum ionized magnesium, not its total serum level, was different in migraineurs from normal individuals. MATERIALS & METHODS: In this case control study, all participants were recruited from Neurology Clinic of Imam Hossein Hospital, Tehran, Iran. Ninety-six people were entered in the study, 48 for each of case and control groups. The two groups were matched by age and sex. Migrainous patients were selected according to the criteria of International Headache Society. Various characteristics of headache were recorded based on patients' report. Controls had no history of migraine or any significant chronic headaches. Serum ionized magnesium level was measured in both of the case and control groups and the results were compared to each other. P value of <0.05 was considered as significant. RESULTS: Case group consisted of 13 males, 35 females, and control group included 14 males, as well as 34 females. Mean age was 33.47± 10.32 yr for case and 30.45 ±7.12 yr for control group. Twenty-eight patients described the intensity of their headaches as moderate; 15 patients had severe and the 5 remainders had only mild headaches. Mean serum level of ionized Mg was 1.16± 0.08 in case group and 1.13± 0.11 in control group of no significant difference (P >0.05). CONCLUSION: Serum ionized magnesium, which is the active form of this ion, was not significantly different in migraineurs and those without migraine. This may propose a revision regarding pathogenesis of migraine and question the role of magnesium in this type of headache.

Low incidence of alpha-1-antitrypsin deficiency in Iranian patients with neonatal cholestasis.

BACKGROUND/AIMS: There is little data concerning the incidence of alpha-1-antitrypsin"(AAT) deficiency, the most common genetic cause of liver disease, among children with neonatal cholestasis in Iran. Thus, this study was performed to analyze AAT deficiency in this group of patients. MATERIALS AND METHODS: DNA samples from patients with neonatal cholestasis were investigated for Pi S and Pi Z alleles, using polymerase chain reaction-restriction fragment length polymorphism. RESULTS: Thirty patients with neonatal cholestasis were enrolled. Among those who underwent biopsies, the results revealed neonatal hepatitis in 19, bile duct paucity in 1, steatohepatitis in 1, bile duct proliferation in 1, cirrhosis in 2, fibrosis in 2, and extrahepatic biliary atresia in 1 patient. No mutant allele was found in any patient. CONCLUSION: The incidence of AAT deficiency is very low in Iran; therefore, screening for AAT is not recommended for patients with neonatal cholestasis in Iran.

Four novel p.N385K, p.V36A, c.1033-1034insT and c.1417-1418delCT mutations in the sphingomyelin Phosphodiesterase 1 (SMPD1) gene in patients with types A and B Niemann-Pick disease (NPD).

BACKGROUND: Types A and B Niemann-Pick disease (NPD) are autosomal-recessive lysosomal storage disorders caused by the deficient activity of acid sphingomyelinase due to mutations in the sphingomyelin phosphodiesterase 1 (SMPD1) gene. METHODS: In order to determine the prevalence and distribution of SMPD1 gene mutations, the genomic DNA of 15 unrelated Iranian patients with types A and B NPD was examined using PCR, DNA sequencing and bioinformatics analysis. RESULTS: Of 8 patients with the p.G508R mutation, 5 patients were homozygous, while the other 3 were heterozygous. One patient was heterozygous for both the p.N385K and p.G508R mutations. Another patient was heterozygous for both the p.A487V and p.G508R mutations. Two patients (one homozygous and one heterozygous) showed the p.V36A mutation. One patient was homozygous for the c.1033-1034insT mutation. One patient was homozygous for the c.573delT mutation, and 1 patient was homozygous for the c.1417-1418delCT mutation. Additionally, bioinformatics analysis indicated that two new p.V36A and p.N385K mutations decreased the acid sphingomyelinase (ASM) protein stability, which might be evidence to suggest the pathogenicity of these mutations. CONCLUSION: with detection of these new mutations, the genotypic spectrum of types A and B NPD is extended, facilitating the definition of disease-related mutations. However, more research is essential to confirm the pathogenic effect of these mutations.

Detection of intragenic SMN1 mutations in spinal muscular atrophy patients with a single copy of SMN1.

Proximal spinal muscular atrophy is an autosomal recessive disorder characterized by symmetrical muscle weakness due to degeneration of alpha motor neurons in the spinal cord. Homozygous deletions in the SMN1 have been reported in more than 90% of spinal muscular atrophy cases. Compound heterozygous patients account for approximately 4% of spinal muscular atrophy cases. In this study, we performed a quantitative test in 20 of 87 spinal muscular atrophy patients who did not have homozygous deletion of SMN1. Mutation screening of SMN1 gene was performed in 4 patients who have only 1 copy of SMN1 to identify intragenic mutations. In addition to a previously described missense mutation in exon 4 (p.A188S/ c.562G>T), we identified 2 novel mutations including a single nucleotide insertion in exon 7 (c.861_862insT/p.R288X) and a deletion of nucleotide G in exon 3 (c.286delG/p.D96Tfs*53). Our results suggested that about 4% of spinal muscular atrophy patients have subtle mutations and might be considered in laboratory examination.