The First Report of Iranian Registry of Patients with Spinal Muscular Atrophy.

BACKGROUND: Insufficient amounts of survival motor neuron protein is leading to one of the most disabling neuromuscular diseases, spinal muscular atrophy (SMA). Before the current study, the detailed characteristics of Iranian patients with SMA had not been determined. OBJECTIVE: To describe the key demographic, clinical, and genetic characteristics of patients with SMA registered in the Iranian Registry of SMA (IRSMA). METHODS: IRSMA has been established since 2018, and the demographic, clinical, and genetic characteristics of patients with SMA were recorded according to the methods of treat neuromuscular disease (TREAT-NMD) project. RESULTS: By October 1, 2022, 781 patients with 5q SMA were registered. Of them, 164 patients died, the majority of them had SMA type 1 and died during the first 20 months of life. The median survival of patients with type 1 SMA was 23 months. The consanguinity rate in 617 alive patients was 52.4%, while merely 24.8% of them had a positive family history. The most common type of SMA in live patients was type 3. Morbidities were defined as having scoliosis (44.1%), wheelchair dependency (36.8%), tube feeding (8.1%), and requiring mechanical ventilation (9.9%). Most of the registered patients had a homozygous deletion of SMN1, while the frequency of patients with higher copy numbers of SMN2, was less in more severe types of the disease. Earlier onset of the disease was significantly seen in patients with lower copy numbers of SMN2. The neuronal apoptosis inhibitory protein (NAIP) gene deletion was associated with a higher incidence of more severe types of SMA, higher dependency on ventilators, tube feeding, and earlier onset of the disease. CONCLUSIONS: The IRSMA is the first established Iranian nationwide registry of patients with SMA. Using this registry, decision-makers, researchers, and practitioners can precisely understand the epidemiology, characteristics, and genetics of patients with SMA in Iran.

Clinical and Molecular Findings of Autosomal Recessive Spastic Ataxia of Charlevoix Saguenay: an Iranian Case Series Expanding the Genetic and Neuroimaging Spectra.

Autosomal recessive spastic ataxia of Charlevoix Saguenay (ARSACS) is now increasingly identified from all countries over the world, possibly rendering it one of the most common autosomal recessive ataxias. Here, we selected patients harboring SACS variants, the causative gene for ARSACS, in a large cohort of 137 patients with early-onset ataxia recruited from May 2019 to May 2021 and were referred to the ataxia clinic. Genetic studies were performed for 111 out of 137 patients (81%) which led to a diagnostic rate of 72.9% (81 out of 111 cases). Ten patients with the molecular diagnosis of ARSACS were identified. We investigated the phenotypic and imaging spectra of all confirmed patients with ARSACS. We also estimated the frequency of ARSACS in this cohort and described their clinical and genetic findings including seven novel variants as well as novel neuroimaging findings. While the classic clinical triad of ARSACS is progressive cerebellar ataxia, spasticity, and sensorimotor polyneuropathy, it is not a constant feature in all patients. Sensorimotor axonal-demyelinating neuropathy was detected in all of our patients, but spasticity and extensor plantar reflex were absent in 50% (5/10). In all patients, brain magnetic resonance imaging (MRI) showed symmetric linear hypointensities in the pons (pontine stripes) and anterior superior cerebellar atrophy as well as a hyperintense rim around the thalami (thalamic rim). Although infratentorial arachnoid cyst has been reported in ARSACS earlier, we report anterior temporal arachnoid cyst in two patients for the first time, indicating that arachnoid cyst may be an associated imaging feature of ARSACS. We also extended molecular spectrum of ARSACS by presenting 8 pathogenic and one variant of unknown significance (VUS) sequence variants, which 7 of them have not been reported previously. MetaDome server confirmed that the identified VUS variant was in the intolerant regions of sacsin protein encoded by SACS.

Recalcitrant Cutaneous Warts in a Family with Inherited ICOS Deficiency.

Recalcitrant warts, caused by human papillomaviruses (HPVs), can be a cutaneous manifestation of inborn error of immunity. This study investigated the clinical manifestations, immunodeficiency, single-gene susceptibility, and HPV repertoire in a consanguineous family with severe sinopulmonary infections and recalcitrant warts. Clinical and immunologic evaluations, including FACS and lymphocyte transformation test, provided evidence for immunodeficiency. Combined whole-exome sequencing and genome-wide homozygosity mapping were utilized to disclose candidate sequence variants. Whole-transcriptome sequencing was used to concomitantly investigate the HPV genotypes and the consequences of detected sequence variants in the host. The proband, a male aged 41 years, was found to be homozygous for the c.6delG, p.Lys2Asnfs∗17 variant in ICOS, encoding the inducible T-cell costimulator. This variant was located inside the 5 megabase of runs of homozygosity on 2q33.2. RNA sequencing confirmed the deleteriousness of the ICOS variant in three skin biopsies revealing significant downregulation of ICOS and its ligand, ICOSLG. Reads unaligned to the human genome were applied to 926 different viruses, and α-HPV57, ß-HPV107, ß-HPV14, and ß-HPV17 were detected. Collectively, we describe a previously unrecognized inborn error of T-cell immunity to HPVs, indicating that autosomal recessive ICOS deficiency can underlie recalcitrant warts, emphasizing the immunologic underpinnings of recalcitrant warts at the nexus of human and viral genomic variation.

Clinical and imaging outcomes after intrathecal injection of umbilical cord tissue mesenchymal stem cells in cerebral palsy: a randomized double-blind sham-controlled clinical trial.

BACKGROUND: This study assessed the safety and efficacy of intrathecal injection of umbilical cord tissue mesenchymal stem cells (UCT-MSC) in individuals with cerebral palsy (CP). The diffusion tensor imaging (DTI) was performed to evaluate the alterations in white-matter integrity. METHODS: Participants (4-14 years old) with spastic CP were assigned in 1:1 ratio to receive either UCT-MSC or sham procedure. Single-dose (2 × 107) cells were administered in the experimental group. Small needle pricks to the lower back were performed in the sham-control arm. All individuals were sedated to prevent awareness. The primary endpoints were the mean changes in gross motor function measure (GMFM)-66 from baseline to 12 months after procedures. The mean changes in the modified Ashworth scale (MAS), pediatric evaluation of disability inventory (PEDI), and CP quality of life (CP-QoL) were also assessed. Secondary endpoints were the mean changes in fractional anisotropy (FA) and mean diffusivity (MD) of corticospinal tract (CST) and posterior thalamic radiation (PTR). RESULTS: There were 36 participants in each group. The mean GMFM-66 scores after 12 months of intervention were significantly higher in the UCT-MSC group compared to baseline (10.65; 95%CI 5.39, 15.91) and control (ß 8.07; 95%CI 1.62, 14.52; Cohen's d 0.92). The increase was also seen in total PEDI scores (vs baseline 8.53; 95%CI 4.98, 12.08; vs control: ß 6.87; 95%CI 1.52, 12.21; Cohen's d 0.70). The mean change in MAS scores after 12 months of cell injection reduced compared to baseline (-1.0; 95%CI -1.31, -0.69) and control (ß -0.72; 95%CI -1.18, -0.26; Cohen's d 0.76). Regarding CP-QoL, mean changes in domains including friends and family, participation in activities, and communication were higher than the control group with a large effect size. The DTI analysis in the experimental group showed that mean FA increased (CST 0.032; 95%CI 0.02, 0.03. PTR 0.024; 95%CI 0.020, 0.028) and MD decreased (CST -0.035 × 10-3; 95%CI -0.04 × 10-3, -0.02 × 10-3. PTR -0.045 × 10-3; 95%CI -0.05 × 10-3, -0.03 × 10-3); compared to baseline. The mean changes were significantly higher than the control group. CONCLUSIONS: The UCT-MSC transplantation was safe and may improve the clinical and imaging outcomes. TRIAL REGISTRATION: The study was registered with ClinicalTrials.gov ( NCT03795974 ).

Novel variants in critical domains of ATP8A2 and expansion of clinical spectrum.

ATP8A2 is a P4-ATPase that flips phosphatidylserine across membranes to generate and maintain transmembrane phospholipid asymmetry. Loss-of-function variants cause severe neurodegenerative and developmental disorders. We have identified three ATP8A2 variants in unrelated Iranian families that cause intellectual disability, dystonia, below-average head circumference, mild optic atrophy, and developmental delay. Additionally, all the affected individuals displayed tooth abnormalities associated with defects in teeth development. Two variants (p.Asp825His and p.Met438Val) reside in critical functional domains of ATP8A2. These variants express at very low levels and lack ATPase activity. Inhibitor studies indicate that these variants are misfolded and degraded by the cellular proteasome. We conclude that Asp825, which coordinates with the Mg2+ ion within the ATP binding site, and Met438 are essential for the proper folding of ATP8A2 into a functional flippase. We also provide evidence on the association of tooth abnormalities with defects in ATP8A2, thereby expanding the clinical spectrum of the associated disease.

Genetic testing of leukodystrophies unraveling extensive heterogeneity in a large cohort and report of five common diseases and 38 novel variants.

This study evaluates the genetic spectrum of leukodystrophies and leukoencephalopathies in Iran. 152 children, aged from 1 day to 15 years, were genetically tested for leukodystrophies and leukoencephalopathies based on clinical and neuroradiological findings from 2016 to 2019. Patients with a suggestive specific leukodystrophy, e. g. metachromatic leukodystrophy, Canavan disease, Tay-Sachs disease were tested for mutations in single genes (108; 71%) while patients with less suggestive findings were evaluated by NGS. 108 of 152(71%) had MRI patterns and clinical findings suggestive of a known leukodystrophy. In total, 114(75%) affected individuals had (likely) pathogenic variants which included 38 novel variants. 35 different types of leukodystrophies and genetic leukoencephalopathies were identified. The more common identified disorders included metachromatic leukodystrophy (19 of 152; 13%), Canavan disease (12; 8%), Tay-Sachs disease (11; 7%), megalencephalic leukodystrophy with subcortical cysts (7; 5%), X-linked adrenoleukodystrophy (8; 5%), Pelizaeus-Merzbacher-like disease type 1 (8; 5%), Sandhoff disease (6; 4%), Krabbe disease (5; 3%), and vanishing white matter disease (4; 3%). Whole exome sequencing (WES) revealed 90% leukodystrophies and genetic leukoencephalopathies. The total diagnosis rate was 75%. This unique study presents a national genetic data of leukodystrophies; it may provide clues to the genetic pool of neighboring countries. Patients with clinical and neuroradiological evidence of a genetic leukoencephalopathy should undergo a genetic analysis to reach a definitive diagnosis. This will allow a diagnosis at earlier stages of the disease, reduce the burden of uncertainty and costs, and will provide the basis for genetic counseling and family planning.

Identification of novel loss of function variants in MBOAT7 resulting in intellectual disability.

The membrane bound O-acyltransferase domain-containing 7 (MBOAT7) gene codes for an enzyme involved in regulating arachidonic acid incorporation in lysophosphatidylinositol. Patients with homozygous nonsense mutations in MBOAT7 have intellectual disability (ID) accompanied with seizure and autism. Accumulating evidences obtained from human genetic studies have shown that MBOAT7 is also involved in fatty liver disease. Here we identified two novel homozygous variants in MBOAT7, NM_024298.5: c.1062C>A; p.(Tyr354*) and c.1135del; p.(Leu379Trpfs*9), in two unrelated Iranian families by means of whole exome sequencing. Sanger sequencing was performed to confirm the identified variants and also to investigate whether they co-segregate with the patients' phenotypes. To understand the functional consequences of these changes, we overexpressed recombinant wild type MBOAT7 and mutants in vitro and showed these mutations resulted in abolished protein synthesis and expression, indicating a complete loss of function. Albeit, we did not trace any liver diseases in our patients, but presence of globus pallidus signal changes in Magnetic Resonance Images might be indicative of metabolic changes as a result of loss of MBOAT7 expression in hepatic cells. These signal changes could also help as an important marker of MBOAT7 deficiency while analyzing the genomic data of patients with similar phenotypes.

An update on clinical, pathological, diagnostic, and therapeutic perspectives of childhood leukodystrophies.

Introduction: Leukodystrophies constitute heterogenous group of rare heritable disorders primarily affecting the white matter of central nervous system. These conditions are often under-appreciated among physicians. The first clinical manifestations of leukodystrophies are often nonspecific and can occur in different ages from neonatal to late adulthood periods. The diagnosis is, therefore, challenging in most cases.Area covered: Herein, the authors discuss different aspects of leukodystrophies. The authors used MEDLINE, EMBASE, and GOOGLE SCHOLAR to provide an extensive update about epidemiology, classifications, pathology, clinical findings, diagnostic tools, and treatments of leukodystrophies. Comprehensive evaluation of clinical findings, brain magnetic resonance imaging, and genetic studies play the key roles in the early diagnosis of individuals with leukodystrophies. No cure is available for most heritable white matter disorders but symptomatic treatments can significantly decrease the burden of events. New genetic methods and stem cell transplantation are also under investigation to further increase the quality and duration of life in affected population.Expert opinion: The improvements in molecular diagnostic tools allow us to identify the meticulous underlying etiology of leukodystrophies and result in higher diagnostic rates, new classifications of leukodystrophies based on genetic information, and replacement of symptomatic managements with more specific targeted therapies.Abbreviations: 4H: Hypomyelination, hypogonadotropic hypogonadism and hypodontia; AAV: Adeno-associated virus; AD: autosomal dominant; AGS: Aicardi-Goutieres syndrome; ALSP: Axonal spheroids and pigmented glia; APGBD: Adult polyglucosan body disease; AR: autosomal recessive; ASO: Antisense oligonucleotide therapy; AxD: Alexander disease; BAEP: Brainstem auditory evoked potentials; CAA: Cerebral amyloid angiopathy; CADASIL: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy; CARASAL: Cathepsin A-related arteriopathy with strokes and leukoencephalopathy; CARASIL: Cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy; CGH: Comparative genomic hybridization; ClC2: Chloride Ion Channel 2; CMTX: Charcot-Marie-Tooth disease, X-linked; CMV: Cytomegalovirus; CNS: central nervous system; CRISP/Cas9: Clustered regularly interspaced short palindromic repeat/CRISPR-associated 9; gRNA: Guide RNA; CTX: Cerebrotendinous xanthomatosis; DNA: Deoxyribonucleic acid; DSB: Double strand breaks; DTI: Diffusion tensor imaging; FLAIR: Fluid attenuated inversion recovery; GAN: Giant axonal neuropathy; H-ABC: Hypomyelination with atrophy of basal ganglia and cerebellum; HBSL: Hypomyelination with brainstem and spinal cord involvement and leg spasticity; HCC: Hypomyelination with congenital cataracts; HEMS: Hypomyelination of early myelinated structures; HMG CoA: Hydroxy methylglutaryl CoA; HSCT: Hematopoietic stem cell transplant; iPSC: Induced pluripotent stem cells; KSS: Kearns-Sayre syndrome; L-2-HGA: L-2-hydroxy glutaric aciduria; LBSL: Leukoencephalopathy with brainstem and spinal cord involvement and elevated lactate; LCC: Leukoencephalopathy with calcifications and cysts; LTBL: Leukoencephalopathy with thalamus and brainstem involvement and high lactate; MELAS: Mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke; MERRF: Myoclonic epilepsy with ragged red fibers; MLC: Megalencephalic leukoencephalopathy with subcortical cysts; MLD: metachromatic leukodystrophy; MRI: magnetic resonance imaging; NCL: Neuronal ceroid lipofuscinosis; NGS: Next generation sequencing; ODDD: Oculodentodigital dysplasia; PCWH: Peripheral demyelinating neuropathy-central-dysmyelinating leukodystrophy-Waardenburg syndrome-Hirschprung disease; PMD: Pelizaeus-Merzbacher disease; PMDL: Pelizaeus-Merzbacher-like disease; RNA: Ribonucleic acid; TW: T-weighted; VWM: Vanishing white matter; WES: whole exome sequencing; WGS: whole genome sequencing; X-ALD: X-linked adrenoleukodystrophy; XLD: X-linked dominant; XLR: X-linked recessive.

RNASET2-deficient leukoencephalopathy mimicking congenital CMV infection and Aicardi-Goutieres syndrome: a case report with a novel pathogenic variant.

BACKGROUND: Ribonucleases (RNases) are crucial for degradation of ribosomal RNA (rRNA). RNASET2 as a subtype of RNASEs is a 256 amino acid protein, encoded by RNASET2 gene located on chromosome six. Defective RNASET2 leads to RNASET2-deficient leukoencephalopathy, a rare autosomal recessive neurogenetic disorder with psychomotor delay as its main clinical symptom. The clinical findings can be similar to congenital cytomegalovirus (CMV) infection and Aicardi-Goutieres syndrome (AGS). METHODS: Herein, we presented a patient with motor delay, neurological regression, infrequent seizures and microcephaly at 5 months of age. Brain imaging showed white matter involvement, calcification and anterior temporal cysts. Basic metabolic tests, serum and urine CMV polymerase chain reaction (PCR) were requested. According to clinical and imaging findings, screening of RNASET2 and RMND1 genes were performed. The clinical data and magnetic resonance imaging (MRI) findings of previous reported individuals with RNASET2-deficient leukodystrophy were also reviewed and compared to the findings of our patient. RESULTS: Brain MRI findings were suggestive of RNASET2-deficient leukoencephalopathy, AGS and CMV infection. Basic metabolic tests were normal and CMV PCR was negative. Molecular study revealed a novel homozygous variant of c.233C > A; p.Ser78Ter in exon 4 of RNASET2 gene compatible with the diagnosis of RNASET2-deficient leukoencephalopathy. CONCLUSIONS: RNASET2-deficiency is a possible diagnosis in an infant presented with a static leukoencephalopathy and white matter involvement without megalencephaly. Due to overlapping clinical and radiologic features of RNASET2-deficient leukoencephalopathy, AGS and congenital CMV infections, molecular study as an important and helpful diagnostic tool should be considered to avoid misdiagnosis.

Tumefactive Multiple Sclerosis Variants: Report of Two Cases of Schilder and Balo Diseases.

A tumefactive lesion of central nervous system (CNS) is defined as a mass-like lesion with a size greater than 2 cm in brain detected by magnetic resonance imaging (MRI). Neuroimaging may help to distinguish the nature of a tumefactive lesion and therefore, can prevent an unnecessary brain biopsy. Here we emphasized on determining the nature of a CNS tumefactive lesions with the help of MRI and more explanations about demyelinating lesions with focus on Schilder and Balo diseases as two multiple sclerosis variants. We have reported here two boys of 10 and 8 years of age respectively of multiple sclerosis (MS) variants who presented with acute neurologic complications to our hospital as one of the two referral children hospital in Tehran, Iran. Tumefactive demyelinating lesions can be considered a separate entity that itself can contain Schilder disease, Balo disease, some cases of acute disseminated encephalomyelitis (ADEM) or classic MS. MRI can help to establish a diagnosis of a tumefactive lesion and to differentiate among different underlying etiologies.

Dosimetry of gamma chamber blood irradiator using PAGAT gel dosimeter and Monte Carlo simulations.

Currently, the use of blood irradiation for inactivating pathogenic microbes in infected blood products and preventing graft-versus-host disease (GVHD) in immune suppressed patients is greater than ever before. In these systems, dose distribution and uniformity are two important concepts that should be checked. In this study, dosimetry of the gamma chamber blood irradiator model Gammacell 3000 Elan was performed by several dosimeter methods including thermoluminescence dosimeters (TLD), PAGAT gel dosimetry, and Monte Carlo simulations using MCNP4C code. The gel dosimeter was put inside a glass phantom and the TL dosimeters were placed on its surface, and the phantom was then irradiated for 5 min and 27 sec. The dose values at each point inside the vials were obtained from the magnetic resonance imaging of the phantom. For Monte Carlo simulations, all components of the irradiator were simulated and the dose values in a fine cubical lattice were calculated using tally F6. This study shows that PAGAT gel dosimetry results are in close agreement with the results of TL dosimetry, Monte Carlo simulations, and the results given by the vendor, and the percentage difference between the different methods is less than 4% at different points inside the phantom. According to the results obtained in this study, PAGAT gel dosimetry is a reliable method for dosimetry of the blood irradiator. The major advantage of this kind of dosimetry is that it is capable of 3D dose calculation.