Insights from genotype-phenotype correlations by novel SPEG mutations causing centronuclear myopathy.

Centronuclear myopathies (CNM) are a clinically and genetically heterogeneous group of congenital myopathies, defined histologically by increased number of fibres with centrally located nuclei, and type I fibre predominance in muscle biopsy. Myotubular myopathy, the X-linked form of CNM caused by mutations in the phosphoinositide phosphatase MTM1, is histologically characteristic since muscle fibres resemble myotubes. Here we present two unrelated patients with CNM and typical myotubular fibres in the muscle biopsy caused by mutations in striated muscle preferentially expressed protein kinase (SPEG).

[Subacute anti-N-methyl-D-aspartate receptor encephalitis. A serie of 13 paediatric cases].

Introduction: Subacute anti-NMDA receptor encephalitis was recognised in 2007 as a clinical entity, and was first described in young women with ovarian teratoma. The first paediatric series unrelated with tumours was reported in 2009.

Objective: To present the clinical features, treatment, and prognosis of 13 patients with anti-NMDA receptor encephalitis in Chile.

Clinical spectrum of mitochondrial DNA depletion due to mutations in the thymidine kinase 2 gene.

Background: Mitochondrial DNA depletion syndrome is an autosomal recessive disorder characterized by decreased mitochondrial DNA copy numbers in affected tissues. It has been linked to 4 genes involved in deoxyribonucleotide triphosphate metabolism: thymidine kinase 2 (TK2), deoxyguanosine kinase (DGUOK), polymerase gamma (POLG), and SUCLA2, the gene encoding the beta-subunit of the adenosine diphosphate-forming succinyl coenzyme A synthetase ligase.

Objective: To highlight the variability in the clinical spectrum of TK2-related mitochondrial DNA depletion syndrome.