8210 Reversible Proximal Myopathy Due to Severe Vitamin D Deficiency in a Child With Autism

Abstract Disclosure: O. Ozcan: None. S. Subedi: None. S. Velasquez: None. S. Dave-Sharma: None. Introduction: Severe Vitamin D(Vit.D) deficiency can present dramatically and mimic other illnesses. Autism Spectrum Disorder(ASD) is one of the conditions that pose a risk for nutritional deficiency due to the severely restricted diet. Symptoms can be masked and unclear in a child with ASD due to limited verbal communication. Case Presentation: We report an African-American male with ASD, initially presented at 9 years of age with complaints of back pain after a fall and difficulty in walking.Diet history was significant for severely restricted to instant noodles and french fries.Evaluated by peds neurology, the exam showed Grover’s sign, mildly decreased DTRs, and downgoing plantar response. The upper extremity couldn’t be assessed because the patient was not cooperative. CBC, CRP, LFT, ESR, and CPK were sent for possible myopathy and inflammatory conditions. Lab values reported within normal limits other than CPK 462 U/L(reference range 20-200 U/L) and ALK P 1511 U/L(Reference range: 40-130 U/L). Peds neurology suspected progressive muscle disorder. X-rays, electromyography, and MRIs of the spine and hip were within normal limits. Referred to Genetics, basic genetic panels were within normal limits. The patient followed for two years without improvement with the concerns of limb-girdle muscular dystrophy. The patient later presented with persistent shoulder and neck pain to ED. Labs showed CK(elevated 510), LFT (ALK P 1700), BMP (Ca 5.3mg/dl reference range: 8.4 – 10.5mg/dl), Ionized Ca: 2.92 mg/dl (Ref range: 4.8-5.5 mg/dl). The endocrinologist was consulted, and further investigations included PTH 562.5 pg/ml (Ref range: 15-65 pg/ml), Phosphorus: 4.3 mg/dl (3-5 mg/dl), 25 OH Vit.D levels < 4 ng/ml(reference range 30-80ng/ml). X-rays were significant for demineralization. The muscular dystrophy panel resulted negative. The patient was admitted to the inpatient unit and started on calcitriol, CaCO3, and ergocalciferol. After initial stabilization, the patient was discharged home. During the discharge, the patient was still demonstrating problems with walking. The patient was sent home on calcitriol 0.25mcg, CaCO3 tablets, and Ergocalciferol 50 000 units weekly , weekly physical therapy and follow-up by ped. endocrinlogist. As Vit.D levels improved, CPK decreased . With close follow-up, supplements, and physical therapy, myopathy entirely resolved in following 2 years. Conclusion: Vit. D deficiency is an uncommon cause of myopathy and should be in a differential diagnosis for myopathy as the condition is reversible and can be treated. Due to restrictive eating patterns and limited social interactions, patients with ASD are at increased risk for developing nutritional deficiencies. Physicians should maintain a high index of suspicion in patients with restrictive eating. Presentation: 6/2/2024