Uniparental isodisomy of chromosome 2 causing MRPL44-related multisystem mitochondrial disease.

Mutations in nuclear-encoded protein subunits of the mitochondrial ribosome are an increasingly recognised cause of oxidative phosphorylation system (OXPHOS) disorders. Among them, mutations in the MRPL44 gene, encoding a structural protein of the large subunit of the mitochondrial ribosome, have been identified in four patients with OXPHOS defects and early-onset hypertrophic cardiomyopathy with or without additional clinical features. A 23-year-old individual with cardiac and skeletal myopathy, neurological involvement, and combined deficiency of OXPHOS complexes in skeletal muscle was clinically and genetically investigated. Analysis of whole-exome sequencing data revealed a homozygous mutation in MRPL44 (c.467 T > G), which was not present in the biological father, and a region of homozygosity involving most of chromosome 2, raising the possibility of uniparental disomy. Short-tandem repeat and genome-wide SNP microarray analyses of the family trio confirmed complete maternal uniparental isodisomy of chromosome 2. Mitochondrial ribosome assembly and mitochondrial translation were assessed in patient derived-fibroblasts. These studies confirmed that c.467 T > G affects the stability or assembly of the large subunit of the mitochondrial ribosome, leading to impaired mitochondrial protein synthesis and decreased levels of multiple OXPHOS components. This study provides evidence of complete maternal uniparental isodisomy of chromosome 2 in a patient with MRPL44-related disease, and confirms that MRLP44 mutations cause a mitochondrial translation defect that may present as a multisystem disorder with neurological involvement.

Electroconvulsive therapy for severe depression, psychosis and chorea in a patient with Huntington's disease: case report and review of the literature.

AIMS AND METHOD: The psychiatric manifestations of Huntington's disease are myriad and difficult to control. The use of electroconvulsive therapy (ECT) is not commonly considered for this condition. We describe a patient with severe depression, psychomotor retardation, delusions and weight loss who responded to ECT with good control of her symptoms. RESULTS: Both our case and the literature appear to confirm the efficacy of ECT in the treatment of depression in Huntington's disease and suggest that other psychiatric manifestations of Huntington's are also responsive. CLINICAL IMPLICATIONS: ECT is an effective and safe treatment that should be considered earlier in the course of the disease in cases that show limited response to pharmacological therapy. It should also be considered as an adjunct to medical therapy that may simplify polypharmacy and allow better control in patients with debilitating psychiatric manifestations of the disease. There is limited and conflicting evidence for its efficacy in chorea.