African American Adolescent Male Basketball Player with Recurrent Rhabdomyolysis

HISTROTY: A 17y/o African-American male basketball player presented to his PCP's office for a follow-up visit and complained of muscle soreness. The athlete admitted to performing 800 situps, 400 pushups and jogging 2 miles on the beach during the preceding weekend. On 7/19/06, CPK level was found to be 241,026, BUN 12, and creatinine 1.1. The patient was admitted and treated. Past medical history significant for one syncopal episode secondary to dehydration and complicated by rhabdomyolysis during a basketball practice 2 months prior. He denied any regular use of meds or supplements. The patient has been restricted from activity but has hopes of pursuing a college basketball scholarship. During our office visit the athlete also admitted to sweating easily and “caking on salt.” PHYSICAL EXAMINATION: Gen: alert, conversational, well-appearing CV: RRR, no murmurs, no S3 or S4, bilateral symmetrical distal pulses Lungs: CTAB/L Abd: soft, normoactive bowel sounds, no tenderness, no hepatosplenomegaly, no cva tenderness Ext: no edema Musculoskel: Symmetrical full strength 5/5 in the UE/LE, Full AROM Neuro: CNII-XII grossly intact, oriented x 3, no deficits DIFFERENTIAL DIAGNOSIS FOR ETIOLOGY of EXERTIONAL RHABDOMYOLYSIS: Sickle Cell Trait, Metabolic Myopathies including: Inherited Disorder of Glycogenolysis, Glycolysis, Lipid and Purine Metabolism, Mitochondrial Myopathies, Acute Viral Infection, Bacterial Pyomyositis, Hypothyroidism, Drug-Induced, Inflammatory Myopathies TESTS AND RESULTS: sickle cell trait negative, urine organic acid pattern essentially normal, plasma acyclcarnitine profile-wnl, muscle biopsy RESULTS: glycogen and phosphorylase-wnl, phosphofructokinase-low normal range, assay of mitochondrial enzyme activity in muscle-wnl, phosphogly cerate mutase, phosphoglycerate kinase, and lactate dehydrogenase-wnl, diagnostic exercise test with myopathy protocol indicative of abnormal muscle metabolism, DNA analysis negative for CPT gene mutation, skin biopsy for acylcarnitine profile-wnl, cystic fibrosis tests pending FINAL WORKING DIAGNOSIS: Exertional Rhabdomyolysis Secondary to Idiopathic Muscle Metabolism Disorder TREATMENT AND OUTCOMES: The athlete is currently advised to avoid strenuous activity or participation in sports and further work-up is in progress