The Clinical And Pathological Study Of Muscle Glycogen Storage Disease

Objective: To analyze clinical features of muscle glycogen storagedisease (MGSD) and diagnosis value of skeletal muscle biopsy pathology.Methods:1Research data: Sixteen MGSD patients from The Third Hospital ofHebei Medical University neural myopathy genetic specimen repository (fromSeptember2004to September2013) were selected. Retrospectively analyzingclinical and pathological features of skeletal muscle biopsy. The subjects wereselected according to the standards below. The muscle weakness and exerciseintolerance was chronic and progressively aggravated. Auxiliary examinationrevealed blood creatine kinase (CK) increased at varying degrees. EMGshowed myogenic and neurogenic damage. Pathological analysis under lightmicroscope of skeletal muscle biopsy with histochemical and enzymaticstaining: Various sizes, ranging numbers and irregular shape vacuoles werescattered in the cytoplasm of muscle fibers or vacuoles (glycogen loss) andpink stained (glycogen accumulation) were observed in PAS.2To summarize and analyze general information, clinical manifestation,CK and electrophysiological characteristics of sixteen subjects. GeneralizingPathological features of skeletal muscle biopsy frozen section withhistochemical and enzymatic staining.3Pathological analysis of skeletal muscle biopsy, which was embeddedin resin, ultrathin sections through transmission electron microscopy in ninesubjects.Results:1Clinical data:There were thirteen males and three females in sixteen patients. Doctors’visiting ages were from one point four to thirty-eight years old, mean age was twenty-one years. Onset ages were from zero point one to thirty-six years,mean age was seventeen years. Clinical manifestation: sixteen subjects allshowed muscle weakness. Nine-sixteenths cases mainly manifest proximalmuscle strength weakness, muscle strength: Ⅲ-～Ⅳ+degree. One-sixteenthscases mainly manifest distant muscle strength weakness, muscle strength:Ⅳ-degree. Six-sixteenths cases manifest both proximal and distant musclestrength weakness, muscle strength: Ⅱ～Ⅴ-degree. Seven-sixteenths caseswere accompanied by muscle tonus reducing, three-sixteenths cases byexercise intolerance, three-sixteenths cases by myalgia and one-sixteenthscases by respiratory system involvement.2Auxiliary examination:Blood CK: Nine-sixteenths cases were elevated from one hundred andforty-four U/L to two thousand eight hundred and eighty-six U/L. Mean CKwas one thousand and seventy U/L. Seven-sixteenths cases were not seensignificantly abnormality. Liver function: The AST and ALT of three-sixteenths cases were elevated. AST was from fifty-six U/L to six hundredand forty U/L. Mean AST was three hundred and forty-nine U/L. ALT wasfrom sixty U/L to six hundred and forty U/L. Mean ALT was three hundredand nine U/L. Thirteen-sixteenths were not seen significantly abnormality.Liver ultrasound: Two-sixteenths cases had fatty liver. Fourteen-sixteenthswere not seen significantly abnormality. Heart ultrasound: Two-sixteenthscases manifested left ventricular systolic function reducing and ventricularwall motion abnormality. Fourteen-sixteenths were not seen significantlyabnormality. Myocardium nuclide visualization: Two-sixteenths casesmanifest left ventricular inferior wall perfusion decreasing.Fourteen-sixteenths cases were not seen significantly abnormality. EMG:Ten-sixteenths cases showed myogenic abnormality. One-sixteenths caseshowed neurogenic abnormality. Five-sixteenths cases were not seensignificantly abnormality.3Pathological analysis under light microscope of skeletal muscle biopsyfrozen sections with histochemical and enzymatic staining: In hematoxylin-eosin (HE) and modified gomori trichrome (MGT)staining, the cytoplasm of muscle fibers manifested typical vacuoles structureof various sizes, ranging numbers and irregular shape in fourteen cases. Twocases did not have obvious vacuoles. Two cases of MGSDⅡA type patientsmanifested many irregular shape, ranging numbers and soap bubble-likevacuoles in the cytoplasm of muscle fibers. Vacuoles contain basophilicgranular material in HE and purple granular material in MGT. Degenerating,regenerating and necrotic fibers were scattered in fourteen cases. Two casesdid not seen. Vacuoles (glycogen loss) and pink staining (glycogenaccumulation) were observed in periodic acid schiff (PAS) staining of16cases. Resin embedding, semi-thin section, PAS staining: vacuole sites wereglycogen accumulation which manifested pink stained. Acid phosphatasestaining: The activities were grossly increased in two MGSDⅡA cases. Sothey got pathology diagnosis. Phosphatase staining: the activity was absent inone MGSDⅤcase. So she got pathology diagnosis. The other thirteen casespathological diagnosis were MGSD. Typing diagnosis were not clear. Ninecases were observed by biopsy skeletal muscle ultramicro pathology undertransmission electron microscopy: One case of MGSDⅡA infantile patientshowed glycogen granules gathered between myofibrils, lysosomal gathered,double membrane autophagy vacuoles, myeloid bodies, Mitochondrialstructural was indiscriminate, Z lines and myofibrillar network structuredisorder. Eight cases showed glycogen granules gathered under thesarcolemma or between myofibrils only. Granules gathered area myofibrillarnetwork were absence. Mitochondrial structural was indiscriminate.Conclusions:1The general clinical manifestation of MGSD: Chronic progressivelyaggravated muscle weakness, prophase manifest exercise intolerancesometimes, with or without painful muscle spasm and periodicityrhabdomyolysis. It is easily misdiagnosed as metabolism relevant myopathy,muscular dystrophy and mitochondrion myopathy for the lack of specificity.2Blood CK and electrophysiological examination are lack of specificity in the diagnosis of MGSD. In order to evacuate metabolism relevantmyopathy, inflammatory myopathy and mitochondrion myopathy, bloodSedimentation, C-reactive protein, blood lactic acid and thyroid glandfunctions should be tested routinely.3Multitude systems involvement except muscles should be pay moreattention, especially the heart and liver which prompt suspicious diagnosis.4Glycogen vacuoles and glycogen accumulation in the cytoplasm of mu-scle fibers are important pathological diagnosis basis for MGSD. Sopathological analysis of skeletal muscle biopsy play an important role in thediagnosis of MGSD and the differential diagnosis with other skeletalmyopathies. Acid phosphatase staining positive and phosphorylase stainingthe activity is absent which help typing diagnosis of MGSD. The former oneprompts MGSD Ⅱ. The latter one prompts MGSD Ⅴ. Lysosomemyelin-changes under electron microscope supports MGSDⅡA diagnosis.Glycogen granules gathering does not have the specificity in the diagnosis ofMGSD. It can also be seen in other skeletal myopathies which lead to musclefibers degenerating.5Molecular biology test is an important standard for diagnosis ofMGSD. Pathological diagnosis prompts part of pathogenic gene sequencingdirection (MGSDⅡ, MGSDⅤ). The MGSD with unknown pathologicaltyping can sequence probable disease-causing gene according to multitudesystems involvement manifestation or do gene chip and high-flux sequencingto finish diagnosis at the last. Genetic counseling and antenatal diagnosis canbe done further.