LAUSR

Introduction and importance: Lipid storage myopathy due to flavin adenine dinucleotide synthetase 1 (FLAD1) deficiency is an autosomal recessive error of metabolism that causes variable mitochondrial dysfunction. Case presentation: At the age of 3, the patient was found to have movement problems, such as difficulty rising from a chair (Gower’s sign) and climbing stairs, which led to hospital admission and diagnosis. At the age of 4, carrier detection for spinal muscular atrophy was normal; however, at the age of 5, whole-exome sequencing revealed a pathogenic variant of Chr1: 154960762: A>T c.A554T:p.D185V in exon-2 of FLAD1 gene was identified as homozygous. Clinical discussion: In general, it is expected that the treatment of type 2 FLAD1 gene mutation with riboflavin has a better prognosis, but these interventions may not be sufficient for the survival of the patient. Treatment with riboflavin has increased various functions, including skeletal-muscular, and cardiovascular function. As a result, like the patient in our study, the mutation in exon-2 is more severe and less responsive to riboflavin treatment. Conclusion: Checking the FLAD1 gene is recommended in all people with multiple acyl-CoA dehydrogenase deficiency.