Myopathy and parkinsonism in phosphoglycerate kinase deficiency.

A 25-year-old man with exertional myoglobinuria had no evidence of hemolytic anemia, but he had severe parkinsonism that was responsive to levodopa. Phosphoglycerate kinase (PGK) activity was markedly decreased in muscle, and molecular analysis of the PGK1 gene identified the p.T378P mutation that was recently reported in a patient with isolated myopathy. This case reinforces the concept that PGK deficiency is a clinically heterogeneous disorder and raises the question of a relationship between PGK deficiency and idiopathic juvenile Parkinson disease.

Exercise-induced cramp, myoglobinuria, and tubular aggregates in phosphoglycerate mutase deficiency.

We report two patients in whom phosphoglycerate mutase (PGAM) deficiency was associated with the triad of exercise-induced cramps, recurrent myoglobinuria, and tubular aggregates in the muscle biopsy. Serum creatine kinase (CK) levels were elevated between attacks of myoglobinuria. Forearm ischemic exercise tests produced subnormal increases of venous lactate. Muscle biopsies showed subsarcolemmal tubular aggregates in type 2 fibers. Muscle PGAM activities were markedly decreased (3% of the normal mean) and molecular genetic studies showed that both patients were homozygous for a described missense mutation (W78X). A review of 15 cases with tubular aggregates in the muscle biopsies from our laboratory and 15 cases with PGAM deficiency described in the literature showed that this clinicopathological triad is highly suggestive of PGAM deficiency.

Intronic mutation in the PGK1 gene may cause recurrent myoglobinuria by aberrant splicing.

A 33-year-old man with mental retardation and recurrent myoglobinuria demonstrated a deficiency in the phosphoglycerate kinase 1 (PGK1) activity of his muscles and erythrocytes. His PGK1 gene had intronic G-to-A substitution 5 nucleotides downstream from the normal exon 7 5' splice site (IVS7 + 5 G>A). This novel mutation results in a frame shift due to the insertion of 52 bp of intron 7 in the mature mRNA by aberrant splicing.

Carnitine palmitoyltransferase II deficiency: molecular and biochemical analysis of 32 patients.

The authors investigated 32 patients with the muscle form of CPT II deficiency. Total carnitine palmitoyltransferase enzyme system (CPT) activity was normal but abnormally inhibited by malonyl-CoA, palmitoyl-CoA, and the detergents Triton X and Tween 20. Mutation analysis identified three described mutations (S113L, P50H, and F448L) and two novel mutations (M214T and Y479F). Using modeling techniques, a structure could be identified anchoring the protein in the membrane. Only one of the five mutations (Y479F) is located within this region.

Novel mutation in the CPT II gene in a child with periodic febrile myalgia and myoglobinuria.

We have identified a novel missense mutation in the carnitine palmitoyltransferase II (CPT II) gene in a child with CPT II deficiency characterized clinically by episodes of myalgia and myoglobinuria induced by intercurrent febrile illnesses. The patient was heterozygous for a G-to-A substitution at codon 487, changing an encoded glutamic acid to a lysine (E489K), while the other allele carried the common S113L mutation. This case enlarges the spectrum of mutations in patients with CPT II deficiency, and confirms the association of the S113L mutation with the muscular form.

Muscular carnitine palmitoyltransferase II deficiency in infancy.

An 8-month-old female presented with febrile myoglobinuria. The activity of carnitine palmitoyltransferase (CPT) II was decreased to 16% of the control mean, and the oxidation of the long-chain fatty acids was reduced to 25% of the mean in the fibroblasts. Homozygosity for the common mutation, S113L, was identified in the CPT II gene. Residual CPT II activity of more than 10% of the mean and homozygosity for the common mutation S113L are usually associated with a milder reduction of long-chain fatty acid oxidation to about 80% of the control and with a later age of clinical onset. The early clinical presentation in the present patient is unique and was associated with a marked impairment of long-chain fatty acid oxidation, possibly because of other genetic factors. CPT II deficiency should be included in the differential diagnosis of isolated myoglobinuria in infancy.

A splice junction mutation in the alpha(M) gene of phosphorylase kinase in a patient with myopathy.

In a 28-year-old man with myopathy and phosphorylase kinase (PhK) deficiency, we found a G-to-C substitution at the 5' end of an intron in the muscle-specific alpha-subunit gene. The mutation destroys the high-consensus GT sequences at the 5' splice junction of the intron, which causes skipping of the preceding exon. This is the second molecular genetic defect identified in the myopathic variant of PhK deficiency.

Combined defects of muscle phosphofructokinase and AMP deaminase in a child with myoglobinuria.

A 14-year-old boy with exercise-related myalgia and cramps had several episodes of myoglobinuria since early childhood. An episode at 2 years of age caused acute renal failure. Histochemical and biochemical analysis of muscle showed a combined defect of phosphofructokinase (PFK) and adenosine monophosphate (AMP) deaminase. DNA analysis showed that the patient was homozygous for a G-to-C substitution at codon 39 of the PFK gene (previously described in an Italian patient) and for the common mutation found in AMP deaminase deficiency.

Association of genetically proven deficiencies of myophosphorylase and AMP deaminase: a second case of 'double trouble'.

We studied a 25-year-old man with paresis of the limbs and neck, scapular atrophy, facial weakness, exercise intolerance and frequent episodes of myoglobinuria. Muscle histochemistry and biochemistry revealed a combined defect of myophosphorylase and AMP deaminase. Molecular genetic analysis showed that the patient was homozygous for the two most common mutations associated with myophosphorylase and AMP deaminase deficiencies. This is the second documented case of genetic 'double trouble', which should be looked for in patients with unusual severe phenotypes.

Regulation and immunohistochemical analysis of stress protein heme oxygenase-1 in rat kidney with myoglobinuric acute renal failure.

Intramuscular injection of hypertonic glycerol solution to rats results in acute renal injury. In this model, the proximal tubules are characteristically damaged. After glycerol injection renal glutathione (GSH) levels drastically decreased. On the other hand, stress protein heme oxygenase-1 (HO-1) was induced. When N-acetyl cysteine was administered to rats before 1 h glycerol injection, renal function was obviously improved. In this condition, the renal GSH content were sustained in the normal levels and HO-1 protein levels were decreased compared with those of glycerol-treated rats. Induction of HO-1 was accompanied by reduced renal GSH content. In addition, to investigate whether the location of HO-1 protein induced by glycerol injection is restricted to injured region or not in the kidney, we determined the localization of HO-1 protein using immunohistochemical staining. HO-1 protein was identified in the epithelia of the distal tubules, Henle's loop and collecting ducts, but not in the injured proximal tubules.

Mitochondrial trifunctional protein deficiency associated with recurrent myoglobinuria in adolescence.

A 23-year-old man with recurrent myoglobinuria had low muscle-free carnitine levels and deficient fasting ketogenesis. Urinary organic acid analysis showed large amounts of C6-C14 3-hydroxydicarboxylic acids. Mitochondrial trifunctional protein (TP), harboring long-chain enoyl-coenzyme A (CoA) hydratase, long-chain 3-hydroxyacyl-CoA dehydrogenase, and long-chain 3-ketoacyl-CoA thiolase showed markedly decreased activity in fibroblasts. On immunoblot analysis, the TP content of his fibroblasts was less than 2% that of the control cells. TP deficiency can be a life-threatening disorder with early infantile onset, but it can also present in adolescence with recurrent myoglobinuria.

Metabolic myopathies.

Disorders of glycogen, lipid or mitochondrial metabolism may cause two main clinical syndromes, namely (1) progressive weakness (eg, acid maltase, debrancher enzyme, and brancher enzyme deficiencies among the glycogenoses; long- and very-long-chain acyl-CoA dehydrogenase (LCAD, VLCAD), and trifunctional enzyme deficiencies among the fatty acid oxidation (FAO) defects; and mitochondrial enzyme deficiencies) or (2) acute, recurrent, reversible muscle dysfunction with exercise intolerance and acute muscle breakdown or myoglobinuria (with or without cramps) (eg, phosphorylase (PPL), phosphorylase b kinase (PBK), phosphofructokinase (PFK), phosphoglycerate kinase (PGK), phosphoglycerate mutase (PGAM), and lactate dehydrogenase (LDH) among the glycogenoses and carnitine palmitoyltransferase II (CPT II) deficiency among the disorders of FAO or (3) both (eg, PPL, PBK, PFK among the glycogenoses; LCAD, VLCAD, short-chain L-3-hydroxyacyl-CoA dehydrogenase (SCHAD), and trifunctional enzyme deficiencies among the FAO defects; and multiple mitochondrial DNA (mtDNA) deletions). Myoadenylate deaminase deficiency, a purine nucleotide cycle defect, is somewhat controversial and is characterized by exercise-related cramps leading rarely to myoglobinuria.

A microdeletion in cytochrome c oxidase (COX) subunit III associated with COX deficiency and recurrent myoglobinuria.

We have identified a 15-bp microdeletion in a highly conserved region of the mitochondrially encoded gene for cytochrome c oxidase (COX) subunit III in a patient with severe isolated COX deficiency and recurrent myoglobinuria. The mutant mitochondrial DNA (mtDNA) comprised 92% of the mtDNA in muscle and 0.7% in leukocytes. Immunoblots and immunocytochemistry suggested a lack of assembly or instability of the complex. Microdissected muscle fibres revealed significantly higher portions of mutant mtDNA in COX-negative than in COX-positive fibres. This represents the first case of isolated COX deficiency to be defined at the molecular level.

Recurrent myoglobinuria due to carnitine palmitoyltransferase II deficiency: expression of the molecular phenotype in cultured muscle cells.

Carnitine palmitoyltransferase II deficiency (CPT II) is an autosomal recessive disorder and the most frequent cause of hereditary myoglobinuria. We report the case of a young man who presented a severe fever-induced episode of rhabdomyolysis and myoglobinuria resulting in acute renal failure. Cultured skeletal muscle cells have been used for the biochemical and molecular characterization of the defect in this patient. Immunoblot analysis revealed reduced steady-state level of CPT II protein. A PCR-based method detected the common Ser113Leu substitution only in one allele, suggesting that the patient is a compound heterozygote for this common mutation and a different as yet unidentified mutation.

Myoglobinuria due to quail poisoning.

Quail poisoning is known to produce an acute myoglobinuric syndrome. The cause of this syndrome is still unknown. It has been suggested that a toxic effect or a genetic sensitivity plays a major role. Ten patients with a history of quail poisoning were examined to determine their present state and the course of the disease. A muscle biopsy was performed in 2 of these patients who complained of muscle cramps after exercise. The activities of several glycolytic mitochondrial and lipolytic enzymes were estimated. In all 10 patients the physical examination, electromyogram findings and conduction velocities were normal. Serum levels of CK, aldolase and lactic acid were also within normal range. In the 2 patients with cramps, all enzyme activities were normal in muscle tissue. Our findings possibly exclude a preexisting enzyme defect as a cause of myoglobinuria in quail poisoning. Considering that 4 of our patients continued the consumption of quails without further problems, we suggest that the major factor contributing to quail poisoning must be toxic.

Cytochrome c oxidase deficiency presenting as recurrent neonatal myoglobinuria.

Markedly reduced cytochrome c oxidase (COX) activity was found in cultured skin fibroblasts of an infant with recurrent episodes of acute myoglobinuria, hypertonia, muscle stiffness and elevated plasma levels of sarcoplasmic enzymes (creatine kinase 96950 U/l, normal below 150) since the age of 3 weeks (COX activity: 36 nmol/min/mg protein; normal 65-440; COX/succinate cytochrome c reductase ratio: 1.4, normal 3.0 +/- 0.4). The expression of the disease in cultured fibroblasts allowed us to carry out a prenatal diagnosis during the next pregnancy. Hitherto, mitochondrial respiratory chain deficiency has not been established as a cause of recurrent myoglobinuria in childhood. Since most cases of myoglobinurias remain poorly understood, we suggest giving consideration to respiratory chain deficiency in elucidating the origin of unexplained recurrent myoglobinuria in childhood, especially when seemingly unrelated symptoms are present.

Lactate dehydrogenase M-subunit deficiencies: clinical features, metabolic background, and genetic heterogeneities.

Lactate dehydrogenase M-subunit deficiency was first reported 1980 as an exertional myoglobinuria. Since then, 6 Japanese and 3 Caucasian families have been reported. Also, typical skin lesions were observed in 1 Japanese patient. Since then, 2 families, one Japanese and one Caucasian, have been found with this typical skin eruption. The metabolic background of exertional myoglobinuria was demonstrated as a result of the impaired reoxidation of NADH produced by glyceraldehyde-3-phosphate-dehydrogenase (G3PD) action. The excess NADH was partly reoxidized by the action of alpha-glycerophosphate dehydrogenase abundant in cytosolic fraction of skeletal muscle. This enzyme reoxidizes excess NADH simultaneously draining out triose phosphate from the glycolytic pathway. Abortive glycolysis results in impaired ATP production followed by rhabdomyolysis. Genomic analysis revealed the heterogeneities of the mutations of this disease.

[Clinical and biochemical analysis of 27 patients with myoglobinuria of unknown causes].

We examined the clinical and biochemical features of 27 cases with acute myoglobinuria who had been suspected of having metabolic myopathies. The systematic biochemical studies included the measurements of 13 glycolytic enzymes, mitochondrial respiratory chain enzymes, carnitine palmitoyltransferase (CPT) and 5 enzymes of fatty acid beta-oxidation. Enzyme defects were found in 9 patients using muscle biopsy specimens: phosphorylase deficiency in 3, CPT deficiency in 4 and phosphoglycerate kinase deficiency in 2. One patient was diagnosed as MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes) with the histopathological examination and clinical data. A suspicion of beta-oxidation disorder was entertained in some patients of which the activities were about 50% of control means. However, no evidence to substantiate its significance as the enzyme defects was obtained from our data. Sixteen of 17 undiagnosed cases could be divided into two groups according to precipitating factors as follows: one had exercise as the factors and the other had infection. These groups also showed some differences in clinical features. In the infection group, myoglobinuria tended to progress more rapidly and was occasionally followed by acute renal failure. And some cases had additional associated conditions such as mental retardation or epilepsy. On the other hand, the exercise group had only myopathic symptoms. The difference in these clinical features between the two groups suggested that they had the different pathogenic mechanisms respectively.

Molecular genetic studies of muscle lactate dehydrogenase deficiency in white patients.

We identified two new mutations in 2 white patients with muscle lactate dehydrogenase deficiency. Both patients had exercise intolerance, cramps, and recurrent myoglobinuria. One patient was homozygous for a 2-bp deletion in exon 5, resulting in a frameshift with premature termination of translation. The second patient was homozygous for a G-->A substitution at the 3' end of exon 2, leading to exon skipping and splicing of exon 1 to exon 3; the aberrantly spliced messenger RNA contains a frameshift, resulting in premature termination of translation. The present report provides evidence of molecular genetic heterogeneity in white patients with muscle lactate dehydrogenase deficiency.