The Biochemistry Analysis Of Riboflavin Responsive Lipid Storage Myopathy

Objective:To clarify the clinical,pathological and biological features of riboflavin responsive lipid storage myopathy(RR-LSM).Methods:The clinical data and therapeutic effects of 19 LSM patients were summarize retrospectively.The clinical and pathological presentation confirmed RR-LSM definitely.All patients were subjected to urine oganic acids analysis and bloo acyl-camitine profile.Results:1.clinical data:All patients were subacute onset.The proximal and trunk muscle weakness were the most common clinical features and exercise intolerance was also noticeable.Neck muscles Weakness were found in 16 cases,and chewing muscles were involved in 14 cases.17 patients displayed elevated plasma creatine kinase(CK) from sevral folds to 20 folds.All patients showed marked and quick improvement of symptoms after riboflavin therapy(15-150mg).2.pathological feature: Muscle Biopsy study showed marked increased lipid droplets in muscle fibers, predominantly in typeâ… fibers.On SDH,diffuse decreased activity of enzymatic activity was found in 3 patients.On MGT,several ragged red fibers(RRFs) were seen in 3 patients.3.biological results:Urine analysis revealed that 11 out of 13 samples collected during crisis were glutaric aciduria typeâ…¡(GAâ…¡),and blood acyl-camitine profile indicated that 17 out of 19 patients were multiple acyl-CoA dehydrogenation deficiency(MADD).Conclusions:LSM is characterized by preferential involvement of neck and trunck muscles. The distinct pathological feature is lipid accumulation in muscle fibers.Our data suggest that MADD(Glutaric aciduria typeâ…¡) should take responsibility for our 17 LSM patients who are responsive to riboflavin,indicating RR-LSM is mainly due to MADD.