National survey on the prevalence of single-gene aetiologies for genetic developmental and epileptic encephalopathies in Italy.

Background: We aimed to estimate real-world evidence of the prevalence rate of genetic developmental and epileptic encephalopathies (DEEs) in the Italian population over a 11-year period.

Methods: Fifteen paediatric and adult tertiary Italian epilepsy centres participated in a survey related to 98 genes included in the molecular diagnostic workflows of most centres. We included patients with a clinical diagnosis of DEE, caused by a pathogenic or likely pathogenic variant in one of the selected genes, with a molecular diagnosis established between 2012 and 2022.

Reduction of sacsin levels in peripheral blood mononuclear cells as a diagnostic tool for spastic ataxia of Charlevoix-Saguenay.

Autosomal recessive spastic ataxia of Charlevoix-Saguenay is a rare neurodegenerative disease caused by biallelic variants in the gene encoding for sacsin. More than 200 pathogenic variants have been identified to date, most of which are missense. It is likely that the prevalence of autosomal recessive spastic ataxia of Charlevoix-Saguenay is underestimated due to the lack of an efficient diagnostic tool able to validate variants of uncertain significance.

Olanzapine, risperidone and ziprasidone differently affect lysosomal function and autophagy, reflecting their different metabolic risk in patients.

The metabolic effects induced by antipsychotics in vitro depend on their action on the trafficking and biosynthesis of sterols and lipids. Previous research showed that antipsychotics with different adverse effects in patients cause similar alterations in vitro, suggesting the low clinical usefulness of cellular studies. Moreover, the inhibition of peripheral AMPK was suggested as potential aetiopathogenic mechanisms of olanzapine, and different effects on autophagy were reported for several antipsychotics.

A Novel De novo Heterozygous Mutation in the SON Gene Associated with Septo-optic Dysplasia: A New Phenotype.

Septo-optic dysplasia (SOD) syndrome is a rare congenital disorder characterized by a classic triad of optic nerve/chiasm hypoplasia, agenesis of septum pellucidum and corpus callosum, and hypoplasia of the hypothalamic-pituitary axis.Herein, we report the clinical case of 2-year-old boy presenting with psychomotor delay, nystagmus, congenital hypothyroidism, and a clinically relevant growth delay. The neuroradiological examination showed partial segmental agenesis of the corpus callosum, agenesis of the septum pellucidum, optic nerve hypoplasia, and a small pituitary gland with a small median pituitary stalk.

Extreme phenotypic heterogeneity in non-expansion spinocerebellar ataxias.

Although the best-known spinocerebellar ataxias (SCAs) are triplet repeat diseases, many SCAs are not caused by repeat expansions. The rarity of individual non-expansion SCAs, however, has made it difficult to discern genotype-phenotype correlations. We therefore screened individuals who had been found to bear variants in a non-expansion SCA-associated gene through genetic testing, and after we eliminated genetic groups that had fewer than 30 subjects, there were 756 subjects bearing single-nucleotide variants or deletions in one of seven genes: CACNA1A (239 subjects), PRKCG (175), AFG3L2 (101), ITPR1 (91), STUB1 (77), SPTBN2 (39), or KCNC3 (34).

Case report: A novel deletion and a missense variant in a child with complicated, rapidly progressive spastic paraplegia.

Defects in are associated with either epileptic phenotypes or a spastic paraplegia subtype known as SPG77. Here, we describe an 8-year-old patient with severe and complicated spastic paraplegia, carrying a missense variant (p.Pro361Leu) and a novel intragenic deletion in Of note, the disease is unexpectedly progressing rapidly and in a biphasic way differently from the previously reported cases.

A case of a childhood onset developmental encephalopathy with a novel de novo truncating variant in the Membrane Protein Palmitoylated 5 (MPP5) gene.

Background: Membrane Protein Palmitoylated 5 (MPP5) is a highly conserved apical complex protein, essential for cell polarity. Defects in neuronal cell polarity are associated with neurologic disorders. Only three patients with heterozygous MPP5 de novo variants have been reported so far, with global developmental delay, behavioral changes and in only one case epileptic seizures.

Rescue of lysosomal function as therapeutic strategy for SPG15 hereditary spastic paraplegia.

SPG15 is a hereditary spastic paraplegia subtype caused by mutations in Spastizin, a protein encoded by the ZFYVE26 gene. Spastizin is involved in autophagosome maturation and autophagic lysosome reformation and SPG15-related mutations lead to autophagic lysosome reformation defects with lysosome enlargement, free lysosome depletion and autophagosome accumulation. Symptomatic and rehabilitative treatments are the only therapy currently available for patients.

Case Reports: Novel Missense Variants in the Filamin C Actin Binding Domain Cause Variable Phenotypes.

Filamin C is a large dimeric actin-binding protein, most prevalent in skeletal and cardiac muscle Z-discs, where it participates in sarcomere mechanical stabilization and intracellular signaling, interacting with numerous binding partners. Dominant heterozygous mutations of Filamin C gene cause several forms of myopathy and structural or arrhythmogenic cardiomyopathy. In this report we describe clinical and molecular findings of two Italian patients, in whom we identified two novel missense variants located within the Filamin C actin binding domain.

Superior Cerebellar Atrophy: An Imaging Clue to Diagnose -Related Disorders.

The inositol 1,4,5-triphosphate receptor type 1 () gene encodes an InsP-gated calcium channel that modulates intracellular Ca release and is particularly expressed in cerebellar Purkinje cells. Pathogenic variants in the gene are associated with different types of autosomal dominant spinocerebellar ataxia: SCA15 (adult onset), SCA29 (early-onset), and Gillespie syndrome. Cerebellar atrophy/hypoplasia is invariably detected, but a recognizable neuroradiological pattern has not been identified yet.

Clinical-Genetic Features Influencing Disability in Spastic Paraplegia Type 4: A Cross-sectional Study by the Italian DAISY Network.

Background And Objectives: Hereditary spastic paraplegias (HSPs) are a group of inherited rare neurologic disorders characterized by length-dependent degeneration of the corticospinal tracts and dorsal columns, whose prominent clinical feature is represented by spastic gait. Spastic paraplegia type 4 (SPG4, SPAST-HSP) is the most common form. We present both clinical and molecular findings of a large cohort of patients, with the aim of (1) defining the clinical spectrum of SPAST-HSP in Italy; (2) describing their molecular features; and (3) assessing genotype-phenotype correlations to identify features associated with worse disability.

SCN2A Pathogenic Variants and Epilepsy: Heterogeneous Clinical, Genetic and Diagnostic Features.

Pathogenic variants of the gene (MIM 182390) are associated with several epileptic syndromes ranging from benign familial neonatal-infantile seizures (BFNIS) to early infantile epileptic encephalopathy. The aim of this work was to describe clinical features among five patients with concomitant gene variants and cryptogenic epileptic syndromes, thus expanding the spectrum of phenotypic heterogeneity. variants were identified in four patients, while one inherited variant was identified in a patient with an unaffected carrier biological father with somatic mosaicism.

Long-term follow-up in a cohort of children with isolated corpus callosum agenesis at fetal MRI.

Objective: This long-term retrospective follow-up study aimed to address the knowledge gap between prenatal diagnosis of complete isolated Agenesis of Corpus Callosum (cACC) at fetal MRI and postnatal neurodevelopmental outcome to improve prenatal counseling for parents.

Methods: Data on fetuses with isolated cACC from a single-center MRI database built up in two decades were considered. Detailed postnatal clinical, neuropsychological evaluations were performed and descriptions of available neuroradiological and genetic data were provided.

Acid Sphingomyelinase Controls Early Phases of Skeletal Muscle Regeneration by Shaping the Macrophage Phenotype.

Skeletal muscle regeneration is a complex process involving crosstalk between immune cells and myogenic precursor cells, i.e., satellite cells.

Epilepsia partialis continua associated with the p.Arg403Cys variant of the DNM1L gene: an unusual clinical progression with two episodes of super-refractory status epilepticus with a 13-year remission interval.

Dynamin-1-like (DNM1L) is a gene located on chromosome 12p11.21 that encodes for dynamin-related protein (DRP1), a GTPase involved in mitochondrial and peroxisomal fusion, which plays a pivotal role in brain development. The missense variant, p.

Monoallelic KIF1A-related disorders: a multicenter cross sectional study and systematic literature review.

Background: Monoallelic variants in the KIF1A gene are associated with a large set of clinical phenotypes including neurodevelopmental and neurodegenerative disorders, underpinned by a broad spectrum of central and peripheral nervous system involvement.

Methods: In a multicenter study conducted in patients presenting spastic gait or complex neurodevelopmental disorders, we analyzed the clinical, genetic and neuroradiological features of 28 index cases harboring heterozygous variants in KIF1A. We conducted a literature systematic review with the aim to comparing our findings with previously reported KIF1A-related phenotypes.

Refining the mutational spectrum and gene-phenotype correlates in pontocerebellar hypoplasia: results of a multicentric study.

Background: Pontocerebellar hypoplasias (PCH) comprise a group of genetically heterogeneous disorders characterised by concurrent hypoplasia of the pons and the cerebellum and variable clinical and imaging features. The current classification includes 13 subtypes, with ~20 known causative genes. Attempts have been made to delineate the phenotypic spectrum associated to specific PCH genes, yet clinical and neuroradiological features are not consistent across studies, making it difficult to define gene-specific outcomes.

Novel SPTBN2 gene mutation and first intragenic deletion in early onset spinocerebellar ataxia type 5.

In the present study, we describe two novel cases of SCA5 with early onset. The first one, carrying a novel heterozygous de novo missense mutation in SPTBN2 gene, showed a striking very severe cerebellar atrophy and reduction of volume of the pons at a very young age (16 months). The latter, carrying the first de novo intragenic deletion so far reported in SPTBN2 gene, showed a mild cerebellar atrophy involving the hemispheres and a later onset.