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Background: Pompe disease is a glycogen storage disease primarily affecting striated muscles. Despite its main manifestation in muscles, patients with Pompe disease may exhibit non-muscle symptoms, such as hearing loss, suggesting potential involvement of sensory organs or the nervous system due to glycogen accumulation., Aims: This study aimed to evaluate the presence of concomitant small and large fiber neuropathy in patients with Pompe disease., Methods: In this case series study, nine patients with Pompe disease without complaints of neuropathy were evaluated. Small fiber neuropathy was assessed using the Small Fiber Neuropathy Screening List (SFNSL) and SUDOSCAN R , while the sympathetic system was evaluated through Sympathetic Skin Response (SSR), and large fiber neuropathy was assessed through electrodiagnostic findings., Results: Small fiber neuropathy was detected in seven patients (77.8%) according to the SFNSL. Three patients (3/9, approximately 30%) exhibited positive electrophysiological tests, including SSR, SUDOSCAN R , and nerve conduction studies for neuropathy. They also had positive SFNSL results., Conclusions: This study indicates that neuropathy can be a comorbid condition in Pompe disease, emphasizing the importance of screening for this disabling condition., Competing Interests: Declarations. Ethics approval and consent to participate: This study was conducted in accordance with the principles outlined in the Declaration of Helsinki and was approved by the Research Ethics Committee of Shahid Beheshti University of Medical Sciences (approval number: IR.SBMU.MSP.REC.1400.068). Informed consent was obtained from parents and patients, and the patient’s privacy and confidentiality were strictly maintained throughout the study. Consent for publication: We did not use any identifying images or other personal or clinical details of participants that could compromise their anonymity. Therefore, this item is not applicable to this study. We confirm that all authors listed in the manuscript are aware of the submission and have agreed to submit the paper to this journal. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Next-generation sequencing (NGS) has been proven to be one of the most powerful diagnostic tools for rare Mendelian disorders. Several studies on the clinical application of NGS in unselected cohorts of Middle Eastern patients have reported a high diagnostic yield of up to 48%, correlated with a high level of consanguinity in these populations. We evaluated the diagnostic utility of NGS-based testing across different clinical indications in 1436 patients from Iran, representing the first study of its kind in this highly consanguineous population. A total of 1075 exome sequencing and 361 targeted gene panel sequencing were performed over 8 years at a single clinical genetics laboratory, with the majority of cases tested as proband-only (91.6%). The overall diagnostic rate was 46.7%, ranging from 24% in patients with an abnormality of prenatal development to over 67% in patients with an abnormality of the skin. We identified 660 pathogenic or likely pathogenic variants, including 241 novel variants, associated with over 342 known genetic conditions. The highly consanguineous nature of this cohort led to the diagnosis of autosomal recessive disorders in the majority of patients (79.1%) and allowed us to determine the shared carrier status of couples for suspected recessive phenotypes in their deceased child(ren) when direct testing was not possible. We also highlight the observations of recessive inheritance of genes previously associated only with dominant disorders and provide an expanded genotype-phenotype spectrum for multiple less-characterized genes. We present the largest mutational spectrum of known Mendelian disease, including possible founder variants, throughout the Iranian population, which can serve as a unique resource for clinical genomic studies locally and beyond., (© 2024. The Author(s).)

Spinal muscular atrophy with progressive myoclonic epilepsy (SMA-PME) is a rare inherited autosomal recessive disease due to bi-allelic mutations in the ASAH1 gene. SMA-PME is characterized by progressive muscle weakness from three to seven years of age, accompanied by epilepsy, intractable seizures, and sometimes sensorineural hearing loss. To the best of our knowledge, 47 cases have been reported. The present study reports five patients from four different families affected by SMA-PME characterized by progressive myoclonic epilepsy, proximal weakness, and lower motor neuron disease, as proven by electrodiagnostic studies. Genetic analysis identified two different mutations in the ASAH1 (NM_177924.4) gene, a previously reported pathogenic variant, c.125C>T (p.Thr42Met), and a novel likely pathogenic variant c.109C>A (p.Pro37Thr). In addition to reporting a novel pathogenic variant in the ASAH1 gene causing SMA-PME disease, this study compares the signs, phenotypic, and genetic findings of the case series with previous reports and discusses some symptomatic treatments., Competing Interests: Declaration of Competing Interest None., (Copyright © 2022. Published by Elsevier B.V.)

Background: Diagnosis of hereditary hearing loss (HHL) as a heterogeneous disorder is very important especially in countries with high rates of consanguinity where the autosomal recessive pattern of inheritance is prevalent. Techniques such as next-generation sequencing, a comprehensive genetic test using targeted genomic enrichment and massively parallel sequencing (TGE + MPS), have made the diagnosis more cost-effective. The aim of this study was to determine HHL variants with comprehensive genetic testing in our country., Methods: Fifty GJB2 negative individuals with HHL were referred to the Kariminejad-Najmabadi Pathology and Genetics Center, Tehran, one of the reference diagnostic genetic laboratories in Iran, during a 3-year period between 2014 and 2017. They were screened with the OtoSCOPE test, the targeted genomic enrichment and massively parallel sequencing (TGE + MPS) platform after a detailed history had been taken along with clinical evaluation., Results: Among 32 out of 50 GJB2 negative patients (64%), 34 known pathogenic and novel variants were detected of which 16 (47%) were novel, identified in 10 genes of which the most prevalent were CDH23, MYO7A and MYO15A., Conclusion: These results provide a foundation from which to make appropriate recommendations for the use of comprehensive genetic testing in the evaluation of Iranian patients with hereditary hearing loss., Competing Interests: Conflict of interest The authors declare that there is no conflict of interests., (Copyright© Iranian Public Health Association & Tehran University of Medical Sciences.)

The calcium channel, voltage-dependent, L-type, alpha 1S subunit (CACNA1S) gene encodes a skeletal Ca2+ channel which is involved in calcium-dependent processes such as muscle contraction and neurotransmitter release. Mutations in this gene have been accompanied by hypo- and normokalemic periodic paralysis, thyrotoxic periodic paralysis, and susceptibility to malignant hyperthermia. We report the clinical and genetic findings in a patient diagnosed with metabolic myopathy who had episodic attacks of muscle pain and weakness but with no family background of the disease. Next-generation sequencing (NGS) using a panel targeting metabolic myopathy and myotonia genes identified a de novo heterozygous pathogenic variant c.3724A>G, p.Arg1242Gly, in exon 30 of CACNA1S. As the second report of this variant, this case may broaden the CACNA1S-related disease spectrum to include normokalemic periodic paralysis.