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Objectives: This case report aims to contribute to the expanding genotypic-phenotypic spectrum of TTR associated leptomeningeal amyloidosis., Methods: Neuroimaging and targeted TTR Sanger sequencing were performed on a 52-year-old female presenting with cognitive and motor symptoms., Results: The proband, a Sri Lankan woman, presented with a gradually progressive cognitive decline, followed by a rapid deterioration in motor function and level of consciousness. She had a significant family history of an undiagnosed neurological disorder, characterized by cognitive impairment and early death occurring in the fifth decade of life. Analysis of cerebrospinal fluid (CSF) demonstrated elevated protein levels. CT scan of the brain showed extensive leptomeningeal calcifications and hydrocephalus, and gadolinium enhanced magnetic resonance imaging (MRI) demonstrated extensive leptomeningeal enhancement in the brain and spinal cord. Genetic analysis revealed c.113 A > G, p.D38G mutation in TTR, a rare mutation with characteristic clinic-radiological central nervous system features., Discussion: Leptomeningeal amyloidosis represents the least common subtype of familial transthyretin amyloidosis, which is a life-threatening condition. Among the over 150 identified mutations, few are specifically associated with central nervous system disease. The genetic spectrum and clinical phenotypes including neuroimaging findings continue to expand. It is important to maintain a high index of suspicion for leptomeningeal amyloidosis, particularly when the presentation is not acute or when there are relapsing-remitting symptoms. Consideration of family history and early genetic testing are essential to facilitate appropriate treatment and genetic counselling., Competing Interests: Declaration of competing interest None., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Purpose: Nonerythrocytic αII-spectrin (SPTAN1) variants have been previously associated with intellectual disability and epilepsy. We conducted this study to delineate the phenotypic spectrum of SPTAN1 variants., Methods: We carried out SPTAN1 gene enrichment analysis in the rare disease component of the 100,000 Genomes Project and screened 100,000 Genomes Project, DECIPHER database, and GeneMatcher to identify individuals with SPTAN1 variants. Functional studies were performed on fibroblasts from 2 patients., Results: Statistically significant enrichment of rare (minor allele frequency < 1 × 10 -5 ) probably damaging SPTAN1 variants was identified in families with hereditary ataxia (HA) or hereditary spastic paraplegia (HSP) (12/1142 cases vs 52/23,847 controls, p = 2.8 × 10 -5 ). We identified 31 individuals carrying SPTAN1 heterozygous variants or deletions. A total of 10 patients presented with pure or complex HSP/HA. The remaining 21 patients had developmental delay and seizures. Irregular αII-spectrin aggregation was noted in fibroblasts derived from 2 patients with p.(Arg19Trp) and p.(Glu2207del) variants., Conclusion: We found that SPTAN1 is a genetic cause of neurodevelopmental disorder, which we classified into 3 distinct subgroups. The first comprises developmental epileptic encephalopathy. The second group exhibits milder phenotypes of developmental delay with or without seizures. The final group accounts for patients with pure or complex HSP/HA., Competing Interests: Conflict of Interest The authors declare no conflicts of interest., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)