Table 1

Clinical and biochemical features of index patients and affected siblings

PedigreePatient ID numberAffected geneClinical diagnosisCI/CSOther features
MITO00550845NDUFB3 comp hetME, MMND21%*/17%Muscular hypotonia, developmental delay, lactic acidosis blood
MITO03633463NDUFS3 homME, MM28%36%Developmental delay, muscular hypotonia, lactic acidosis, rapid progress of disease
MITO00433284NDUFS8 comp hetME, HCM38%52%Muscular hypotonia, respiratory insufficiency
MITO02133027NDUFS8 homLS8%54%Muscular hypotonia, dyskinesia, epilepsy, lactic acidosis, MRI changes
MITO02144559NDUFS8 homLSNDNDMuscular hypotonia, lactic acidosis blood and CSF, MRI lesions basal ganglia and brainstem, hypertrophic cardiomyopathy
MITO05359029ACAD9 homHCM3%NDMuscular hypotonia, lactic acidosis, exercise intolerance
MITO05359033ACAD9 homHCMNDNDMuscular hypotonia, lactic acidosis, exercise intolerance
MITO05359036ACAD9 homHCMNDNDMuscular hypotonia, lactic acidosis, exercise intolerance
MITO04944409MTFMT comp hetLS16%NDVertical gaze palsy, partial optic atrophy, mental retardation, tetra-spastic, neurosensoric bladder dysfunction
MITO06161606MTFMT hom.LS12%NDDevelopmental delay, muscular hypotonia, ataxia, MRI lesions basal ganglia, periventricular white matter, dorsal column
MITO02833281UnclearME33%49%Developmental delay, muscular hypotonia, spastic tetraparesis, brain atrophy and demyelinisation,
MITO02837800UnclearMENDNDDevelopmental delay, muscular hypotonia, spastic tetraparesis, seizures, brain atrophy, lactic acidosis
MITO03846072UnclearME, MM4%27%*Lactic acidosis, developmental delay, muscular hypotonia, ataxia, coarctation of aorta
MITO02337796UnclearME19%67%Developmental delay, failure to thrive, muscular hypotonia, seizures, lactic acidosis
  • * Normalised to complex IV.

  • CI/CS, complex I activity normalised to citrate synthase in per cent of mean of >10 controls; comp het, compound heterozygous; CSF, cerebrospinal fluid; hom, homozygous; HCM, hypertrophic cardiomyopathy; LS, Leigh syndrome; ME, mitochondrial encephalopathy; MM, mitochondrial myopathy; ND, not determined.