Maria Mazurkiewicz-Bełdzińska

When LHON Mimics Demyelination: Area Postrema Syndrome in Biallelic DNAJC30 Variants

Introduction: Biallelic pathogenic variants in DNAJC30 cause an autosomal recessive form of Leber hereditary optic neuropathy (LHONAR1), traditionally considered a mitochondrially transmitted disorder. The phenotypic spectrum of diseases linked to DNAJC30 includes isolated optic neuropathy, Leigh syndrome spectrum (LSS), and atypical LHON-plus. Case description: Here, we report a 13-year-old boy presenting symptoms of area postrema syndrome (APS), with recurrent vomiting, vertigo, nystagmus, and subacute visual deterioration with central scotoma. Ophthalmological examination revealed bilateral papilledema with telangiectatic vessels, while visual evoked potentials demonstrated severe bilateral optic pathway dysfunction. Brain magnetic resonance imaging (MRI) showed T2/FLAIR hyperintense lesions involving the area postrema and enhancement of the optic nerves, strongly suggesting seronegative neuromyelitis optica spectrum disorder (NMOSD). Extensive immunological and cerebrospinal fluid studies, including anti-aquaporin-4 (AQP4) and anti-MOG antibodies, were negative. High-dose corticosteroids and intravenous immunoglobulins resulted in only transient and incomplete improvement, followed by further visual decline. Additionally, laboratory tests detected elevated lactate plasma levels. Hence, whole-exome sequencing was performed, which identified a homozygous pathogenic DNAJC30 c.152A>G, p.(Tyr51Cys) variant, associated with LHONAR1. After initiation of idebenone therapy, the patient showed significant improvement in visual function, normalization of lactate levels, and complete resolution of the brainstem lesions on follow-up MRI. Conclusions: This case further expands the neuro-ophthalmic spectrum associated with DNAJC30 variants and suggests that DNAJC30-related disease may closely mimic seronegative NMOSD. We highlight that early genetic diagnosis is essential, as recognition of this mitochondrial etiology enables targeted therapy and may substantially improve clinical outcomes.

Resolving Complex Structural Variants in Undiagnosed Rare Movement Disorders via Multimodal Genomics and Multi-omics.

BACKGROUND Long-read sequencing and multi-omic analytical frameworks are increasingly being adopted in rare disease diagnostics. However, clinical workflows comprehensively integrating these methodologies remain uncommon. OBJECTIVE This study aimed to assess the potential and limitations of integrating long-read genomic, transcriptomic, and proteomic analyses to characterize complex structural variants. METHODS Two unrelated patients presenting with dystonia and comorbid neurological features underwent nanopore-based long-read DNA sequencing. In patient 1, complementary transcriptomic and proteomic analyses were performed. RESULTS The workflow enabled the identification and characterization of two pathogenic complex structural variants: a homozygous AluY-mediated inversion disrupting PANK2, underlying neurodegeneration with brain iron accumulation (patient 1), and a heterozygous de novo 16p13.3 duplication-triplication event associated with an atypical dystonia-parkinsonism phenotype (patient 2). CONCLUSIONS Our findings underscore the diagnostic potential of integrated long-read and multi-omic approaches for complex structural variant characterization, while illustrating persistent limitations of automated pipelines and highlighting unpredictable relationships between genomic, transcriptomic, and proteomic findings. © 2026 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

CMIP as a novel candidate gene for neurodevelopmental and neuropsychiatric disorders