title: Mitochondrial cardioencephalomyopathy due to a novel SCO2 mutation in a Brazilian patient: case report and literature review.
abstract: OBJECTIVE
  To review all patients with SCO2 mutations and to describe a Brazilian patient with cardioencephalomyopathy carrying compound heterozygous mutations in SCO2, one being the known pathogenic p.E140K mutation and the other a novel 12-base pair (bp) deletion at nucleotides 1519 through 1530 (c.1519_1530del).
  
  
  METHODS
  Case report and literature review.
  
  
  METHODS
  University hospital.
  
  
  METHODS
  Infant girl presenting with an encephalomyopathy, inspiratory stridor, ventilator failure, progressive hypotonia, and weakness, leading to death.
  
  
  METHODS
  Clinical features, neuroimaging findings, muscle biopsy with histochemical analysis, and genetic studies.
  
  
  RESULTS
  This infant girl was the first child of healthy, nonconsanguineous parents. She developed progressive muscular hypotonia and ventilatory failure. At the end of the first month of life, she developed cardiomegaly and signs of cardiac failure. Routine blood tests showed lactic acidosis and mild elevation of the creatine kinase level. Brain magnetic resonance imaging showed increased T2 and fluid-attenuated inversion recovery signals in the putamen bilaterally. Nerve conduction studies showed severe axonal sensorimotor neuropathy. Muscle biopsy revealed a neurogenic pattern with mitochondrial proliferation and total absence of cytochrome- c oxidase histochemical stain. Sequencing of SCO2 showed that the patient had compound heterozygote SCO2 mutations: the previously described c.1541G>A (p.E140K) mutation and a novel 12-bp deletion at nucleotides 1519 through 1530 (c.1519_1530del). The patient died at age 45 days.
  
  
  CONCLUSIONS
  Our findings and the literature review indicate that it is important to consider the diagnosis of mitochondrial disease in newborns with hypotonia and cardiomyopathy. In our case, the accurate diagnosis of SCO2 mutations is particularly important for genetic counseling.
authors: Pediatric Neurology Service, Department of Pediatrics, Universidade Federal de Minas Gerais, Rua Rio Grande do Norte, 57/606 Belo Horizonte, Minas Gerais 30.130-130, Brazil. gurgelju@yahoo.com.br
authors: Juliana
authors: J
authors: Gurgel-Giannetti
authors: Guilherme
authors: G
authors: Oliveira
authors: Geraldo
authors: G
authors: Brasileiro Filho
authors: Poliana
authors: P
authors: Martins
authors: Mariz
authors: M
authors: Vainzof
authors: Michio
authors: M
authors: Hirano
mesh_terms: D001483:Base Sequence; D001938:Brazil; D009202:Cardiomyopathies / Q000175:diagnosis / Q000235:genetics*; D002352:Carrier Proteins / Q000235:genetics*; D017809:Fatal Outcome; D005260:Female; D006801:Humans; D007223:Infant; D017237:Mitochondrial Encephalomyopathies / Q000175:diagnosis / Q000235:genetics*; D024101:Mitochondrial Proteins / Q000235:genetics*; D018832:Molecular Chaperones; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics*
chemical_list: D002352:Carrier Proteins; D024101:Mitochondrial Proteins; D018832:Molecular Chaperones; C400285:SCO2 protein, human