A 16-year-old girl presented with early-onset cerebellar ataxia, myoclonus, elevated lactic acidosis and hypogonadotropic hypogonadism. Muscle biopsy specimens revealed fibres with a ''ragged'' appearance with increased mitochondria and lipid droplets. Biochemical investigation revealed a deficiency of complex bc(1) (complex III) of the mitochondrial respiratory chain. Genetic analysis did not show either deletions or known mutations of mitochondrial DNA (mtDNA). Phosphorus magnetic resonance spectroscopy (P-31-MRS) showed defective energy metabolism in brain and gastrocnemius muscle. A decreased phosphocreatine (PCr) content was found in the occipital lobes accompanied by normal inorganic phosphate (Pi) and cytosolic pH. These findings represented evidence of a high cytosolic adenosine diphosphate concentration and a relatively high rate of metabolism accompanied by a low phosphorylation potential. Muscle P-31-MRS showed a high Pi content at rest, abnormal exercise transfer pattern and a low rate of PCr postexercise recovery. These findings suggested a deficit of mitochondrial function. Therapy with vitamins K-3 and C normalized brain P-31-MRS indices, whereas it did not affect muscle bioenergetic metabolism. In this patient, the endocrinological disorder is putatively due to a mitochondrial cytopathy. Although an unknown mtDNA mutation cannot be ruled out, the genetic defect may lie in the nuclear genome.
|Titolo:||Early-onset cerebellar ataxia, myoclonus and hypogonadism in a case of mitochondrial complex III deficiency treated with vitamins K3 and C|
|Parole Chiave:||early-onset cerebellar ataxia; myoclonus; mitochondrial complex III deficiency; hypogonadotropic hypogonadism; P-31-mr spectroscopy|
|Settore Scientifico Disciplinare:||Settore MED/26 - Neurologia|
|Data di pubblicazione:||1995|
|Digital Object Identifier (DOI):||10.1007/BF00919592|
|Appare nelle tipologie:||01 - Articolo su periodico|