Lipid storage myopathy due to FLAD1 mutation presenting as a floppy baby

Abstract

Lipid storage myopathy due to flavin adenine dinucleotide synthetase 1 deficiency is an autosomal recessive inborn error of metabolism that includes variable mitochondrial dysfunction resembling multiple acyl-coenzyme A dehydrogenase deficiency (MADD). The phenotype is extremely heterogeneous ranging from a severe disorder presenting in early infancy to a milder course with the onset of muscle weakness in adulthood. There are several studies suggesting riboflavin supplementation tends to improve the clinical outcome, but responses to riboflavin treatment are variable. Here, we describe a 3-month-old boy with flavin adenine dinucleotide synthetase 1 mutation presented as a floppy infant. Lipid storage myopathy with flavin adenine dinucleotide synthetase 1 related MADD, even though rare, should be considered while evaluating a floppy infant because of the scope of availability of treatment, despite variable treatment responses. Therefore, we should have high clinical suspicion, even though the diagnosis is challenging.