11/30. "adult" form of muscular carnitine palmitoyltransferase II deficiency: manifestation in a 2-year-old child. We describe a 6-year-old girl admitted with acute muscular weakness and pain which made her unable to walk. Her parents reported a 4-year history of similar episodes which occurred once or twice a year and always resolved spontaneously. Laboratory investigations showed elevated serum creatine kinase which peaked at day 2 of the attack with 18,600 U/l. carnitine palmitoyltransferase-II deficiency was suspected based on the determination of serum acylcarnitines by tandem mass spectrometry which showed a characteristic elevation of long-chain C16 and C18:1 acylcarnitines. The diagnosis was confirmed by impaired in-vitro palmitate oxidation in blood and the detection of a homozygous substitution S113L in the carnitine palmitoyltransferase-II gene. CONCLUSION: carnitine palmitoyltransferase-II deficiency should be included in the differential diagnosis of isolated muscular weakness even when manifesting in early childhood. ( info) |
12/30. Intolerance to neuroleptics and susceptibility for malignant hyperthermia in a patient with proximal myotonic myopathy (PROMM) and schizophrenia. We report a patient with proximal myotonic myopathy who was treated with neuroleptics because of exacerbating schizophrenia. Under therapy with fluanxol, the patient developed muscle stiffness and oculogyric cramps. Treatment with both amisulpride and olanzapine lead to markedly elevated serum creatine kinase levels. An in-vitro contracture test was positive for halothane. Thus, in patients with all kinds of multisystemic myotonic myopathies, a susceptibility for malignant hyperthermia and intolerance towards neuroleptics should be taken into account. ( info) |
13/30. Structural and functional mutations of the perlecan gene cause Schwartz-Jampel syndrome, with myotonic myopathy and chondrodysplasia. Perlecan, a large heparan sulfate proteoglycan, is a component of the basement membrane and other extracellular matrices and has been implicated in multiple biological functions. Mutations in the perlecan gene (HSPG2) cause two classes of skeletal disorders: the relatively mild Schwartz-Jampel syndrome (SJS) and severe neonatal lethal dyssegmental dysplasia, Silverman-Handmaker type (DDSH). SJS is an autosomal recessive skeletal dysplasia characterized by varying degrees of myotonia and chondrodysplasia, and patients with SJS survive. The molecular mechanism underlying the chondrodystrophic myotonia phenotype of SJS is unknown. In the present report, we identify five different mutations that resulted in various forms of perlecan in three unrelated patients with SJS. Heterozygous mutations in two patients with SJS either produced truncated perlecan that lacked domain V or significantly reduced levels of wild-type perlecan. The third patient had a homozygous 7-kb deletion that resulted in reduced amounts of nearly full-length perlecan. Unlike DDSH, the SJS mutations result in different forms of perlecan in reduced levels that are secreted to the extracellular matrix and are likely partially functional. These findings suggest that perlecan has an important role in neuromuscular function and cartilage formation, and they define the molecular basis involved in the difference in the phenotypic severity between DDSH and SJS. ( info) |
14/30. A patient with proximal myotonic myopathy and parkinsonism. INTRODUCTION: There are two case reports of patients who had proximal myotonic myopathy (PROMM)/myotonic dystrophy (DM) Type 1 and parkinsonism. The combination of myotonic myopathy and parkinsonism is so rare that it may appear to be just a coincidence. However, previous neuropathological examinations of patients who had myotonic dystrophy showed that there were intracytoplasmic inclusion bodies in the nigra and striatum, which raises the possibility that myotonic myopathy may be associated with parkinsonism. In this report we describe a patient with PROMM and a clinically definite parkinsonism to highlight this possibility. CASE REPORT: A 65-year-old man developed proximal muscle weakness, myotonia and atrophy around the age of 55 and was diagnosed as having PROMM at the age of 62. Needle electromyography and muscle biopsy supported the diagnosis. A gene study of the DM Type 1 showed a normal CTG repeat length. At age 63, he developed rest tremor, bradykinesia, hypomimia, stooped posture, and gait disturbance. The postural instability worsened rapidly. The tremor and rigidity were much worse in his right side, where myotonia was more severe. levodopa therapy was only partially effective. CONCLUSION: This is a case report of a patient with PROMM that shows an association with a rapidly progressive form of parkinsonism. We suggest that this may be a novel form of a neurodegenerative disorder, which we name 'Parkinsonism-Myotonic Myopathy-Complex'. ( info) |
| We report a male with late infantile glycogen storage disease type ii (Pompe's disease) who presented at 12 months of age with muscular hypotonia and developmental delay. Oral supplementation with L-alanine has been administered for 5 years. Progression of skeletal myopathy was slow, and cardiomyopathy resolved almost completely. L-alanine may be a valuable supplement for infants with glycogen storage disease type ii. ( info) |
16/30. Paramyotonia congenita with an SCN4A mutation affecting cardiac repolarization. Paramyotonia congenita (PC) is linked to mutations of the skeletal muscle voltage-gated sodium channel alpha-subunit gene SCN4A. The authors report a family where the proband and three of her four children have PC (mutation R1448C) and present repolarization abnormalities at electrocardiogram. They demonstrate that the SCN4A alpha-subunit gene is expressed in normal human heart. Cardiac consequences of mutations of the SCN4A gene may be insignificant in standard conditions, but critical if patients with PC are treated with drugs inducing QT prolongation. ( info) |
17/30. Anaesthetic complications associated with myotonia congenita: case study and comparison with other myotonic disorders. myotonia congenita (MC) is caused by a defect in the skeletal muscle chloride channel function, which may cause sustained membrane depolarisation. We describe a previously healthy 32-year-old woman who developed a life-threatening muscle spasm and secondary ventilation difficulties following a preoperative injection of suxamethonium. The muscle spasms disappeared spontaneously and the surgery proceeded without further problems. When subsequently questioned, she reported minor symptoms suggesting a myotonic condition. Myotonia was found on clinical examination and EMG. The diagnosis MC was confirmed genetically. Neither the patient nor the anaesthetist were aware of the diagnosis before this potentially lethal complication occurred. We give a brief overview of ion channel disorders including malignant hyperthermia and their anaesthetic considerations. ( info) |
18/30. Paramyotonia congenita due to a de novo mutation: a case report. A Japanese man with a negative family history of paramyotonia congenita (PMC) was evaluated for symptoms of cold-induced weakness and stiffness. exercise testing revealed findings characteristic of PMC, and a genetic analysis was therefore performed. A well-known sodium channel mutation for PMC (T1313M) was identified in the patient, but was absent in his biological parents. These data demonstrate the occurrence of a de novo mutation, suggesting that evaluation for PMC should be performed in patients with typical symptoms even if the family history is negative. ( info) |
19/30. Severe infantile hyperkalaemic periodic paralysis and paramyotonia congenita: broadening the clinical spectrum associated with the T704M mutation in SCN4A. The authors describe an Italian kindred with nine individuals affected by hyperkalaemic periodic paralysis associated with paramyotonia congenita (hyperPP/PMC). Periodic paralysis was particularly severe, with several episodes a day lasting for hours. The onset of episodes was unusually early, beginning in the first year of life and persisting into adult life. The paralytic episodes were refractory to treatment. patients described minimal paramyotonia, mainly of the eyelids and hands. All affected family members carried the threonine to methionine substitution at codon 704 (T704M) in exon 13 of the skeletal muscle voltage gated sodium channel gene (SCN4A). The association between T704M and the hyperPP/PMC phenotype has been only recently revealed. Nevertheless, such a severe phenotype has never been reported so far in families with either hyperPP or hyperPP/PMC. These data further broaden the clinical spectrum of T704M and support the evidence that this mutation is a common cause of hyperPP/PMC. ( info) |
20/30. colchicine-induced myopathy with myotonia in a patient with chronic renal failure. Although colchicine induced myopathy has been described in patients with chronic renal failure, colchicine induced myopathy with myotonia has been reported very rarely. A 49-year-old man with chronic renal failure was hospitalised for investigation of fatigue, malaise and severe pain in all extremities. He was on colchicine therapy for 5 months. Neurological examination showed mildly decreased sensation in a distal symmetric pattern in lower extremities, moderate proximal limb weakness, hyporeflexia and severe myalgia on palpation. No clinical evidence of myotonia was present. Laboratory studies showed elevated creatine phosphokinase (CK), lactic dehydrogenase (LDH), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels. Electromyographic (EMG) findings were compatible with myopathy and abundant, widespread myotonic discharges were determined. Muscle biopsy was consistent with vacuolar myopathy. After withdrawal of colchicine, CK, LDH, AST and ALT levels were normalised and the symptoms were disappeared gradually. In conclusion, the detection of myopathic motor unit potentials with myotonic discharges on EMG in patients on colchicine therapy is an important finding and it is possible to suggest that this clue may lead to the invasive procedure of muscle biopsy unnecessary. ( info) |