ABSTRACT Background Hearing loss is one of the most common sensory disorders caused by genetic and environmental factors. Autosomal recessive non‐syndromic hearing loss (ARNSHL) is extremely heterogeneous, with over 100 genes known to be involved. Hearing loss can result from mutations in the LOXHD1 gene, which codes a highly conserved protein known as lipoxygenase and is located at 18q21.1. Despite the association between LOXHD1 mutations and ARNSHL, there are still few documented cases. Methods We examined a case of non‐syndromic hearing loss in an Iranian family with a history of consanguinity and several affected siblings. Next‐generation sequencing (NGS) was conducted on the proband to discover causal genetic alterations. Sanger sequencing was employed to confirm the identified variation. Results A novel likely pathogenic variant in the LOXHD1 gene, c.3713dupA (p.Asp1238Glufs*10), was identified. Sanger sequencing was used to confirm that the affected family members had this frameshift mutation. Conclusion Our findings broaden the mutational range of LOXHD1 linked to ARNSHL. This unique variant enhances the comprehension of the genetic underpinnings of hearing loss and may aid in molecular diagnostics and genetic counseling for impacted families.
Solmaz Hassani Fard Katiraei, Milad Gholami, Mohsen Soosanabadi et al.· Journal of clinical laborato...· 0 citations
Background Joubert syndrome (JS) is a rare neurodevelopmental ciliopathy characterized by a distinctive midbrain-hindbrain malformation, manifested by hypotonia, ataxia, developmental delay, and variable multisystem involvement. The condition exhibits marked clinical and genetic heterogeneity, with over 40 genes implicated to date. However, the mutational spectrum and phenotypic presentation of JS in Middle Eastern populations, where consanguinity is prevalent, remain poorly characterized. Methods We retrospectively reviewed whole-exome sequencing (WES) data from patients referred to the Comprehensive Medical Genetics Center, Shiraz, Iran, between 2019 and 2024. Patients harboring variants in JS-related genes were identified, and their clinical records were analyzed to establish genotype–phenotype correlations. Results A total of 21 cases with variants in JS-associated genes were identified. Neurological manifestations, including developmental delay/intellectual disability, speech defects, seizures, and motor impairment, were the most prevalent findings. Vision problems, renal involvement and polydactyly were also present. Molecular analysis revealed variants in 14 distinct genes, with AHI1 being the most frequently mutated (3 cases), followed by KIAA0586, CSPP1, KIAA0556, CC2D2A, and TMEM67. Eight cases carried pathogenic or likely pathogenic variants, while 12 cases had variants of uncertain significance (VUS), highlighting the diagnostic challenges in this genetically heterogeneous condition. Conclusion This study expands the mutational landscape of JS in the Iranian population and underscores the utility of WES as a first-tier diagnostic tool for JS and related ciliopathies. The high rate of consanguinity in this cohort likely contributes to the enrichment of autosomal recessive forms. Further functional studies are warranted to clarify the pathogenicity of the numerous VUS identified, which will improve genetic counseling and prenatal decision-making for affected families.
Sheyda Khalilian, Mohadeseh Fathi, Zahra Farbood et al.· Molecular Genetics and Metab...· 0 citations