Segmental brainstem myoclonus in ADCK3-Related ataxia: A novel phenomenon?

Segmental Brainstem Myoclonus (SBM) is a rare movement disorder characterized by rhythmic contractions of muscles innervated by brainstem segments. We report a 20-year-old patient with ADCK3-related spinocerebellar ataxia type 9 (SCAR9) presenting with sudden-onset myoclonic movements of the throat, tongue, and soft palate. Brain MRI showed stable findings, including dentate nucleus hyperintensities.

De Novo GRID2 Variant as a Cause of Ataxia with Oculomotor Apraxia and Alpha-Fetoprotein Elevation.

Bi-allelic pathogenic variants in GRID2 have been initially associated to an autosomal recessive form of spinocerebellar ataxia, namely SCAR18. Subsequently, few monoallelic cases have been described. Here we present a new subject harboring a novel de novo heterozygous GRID2 missense variant presenting with progressive ataxia together with cerebellar atrophy and, for the first time, alpha-fetoprotein (AFP) elevation.

Clinical and genetic delineation of autosomal recessive and dominant ACTL6B-related developmental brain disorders.

Purpose: This study aims to comprehensively delineate the phenotypic spectrum of ACTL6B-related disorders, previously associated with both autosomal recessive and autosomal dominant neurodevelopmental disorders. Molecularly, the role of the nucleolar protein ACTL6B in contributing to the disease has remained unclear.

Methods: We identified 105 affected individuals, including 39 previously reported cases, and systematically analysed detailed clinical and genetic data for all individuals.

Improving paediatric movement disorders care: Insights on rating scales utilization and clinical practice.

Aim: This exploratory study evaluates rating scale usage by experts from the European Reference Network for Rare Neurological Diseases (ERN-RND) for paediatric MD, considering factors like diagnosis, intellectual disability, age, and transition to adult care. The aim is to propose a preliminary framework for consistent application.

Methods: A multicentre survey among 25 ERN-RND experts from 10 European countries examined rating scale usage in paediatric MD, categorizing MD into acute, non-progressive, and neurodegenerative types.

Bi-allelic variants in SNF8 cause a disease spectrum ranging from severe developmental and epileptic encephalopathy to syndromic optic atrophy.

The endosomal sorting complex required for transport (ESCRT) machinery is essential for membrane remodeling and autophagy and it comprises three multi-subunit complexes (ESCRT I-III). We report nine individuals from six families presenting with a spectrum of neurodevelopmental/neurodegenerative features caused by bi-allelic variants in SNF8 (GenBank: NM_007241.4), encoding the ESCRT-II subunit SNF8.