Background We present the case of a 12-year-old female patient with a complex medical history. Initially, she presented with recurrent epistaxis and was subsequently diagnosed with metabolic syndrome. Her diagnostic journey involved high blood glucose levels, autoimmune thyroid disease, obesity, and cardiac abnormalities.

Case Report(s) The patient was diagnosed with diabetes at the age of 10 after experiencing polyuria and polydipsia. Initial lab results indicated high HbA1c and fasting blood glucose levels. Despite the diagnosis of type 2 diabetes and the absence of autoantibodies, her glucose control deteriorated. She was treated with insulin and metformin. Furthermore, autoimmune primary hypothyroidism was discovered, and she was started on levothyroxine. The patient‘s obesity had been present since early childhood, and her BMI exceeded the 98th percentile. She also exhibited signs of acanthosis nigricans. Additional investigations showed elevated LDL levels and positive thyroid antibodies.

Conclusion(s) The patient‘s medical history was further complicated by hypertrophied obstructive cardiomyopathy and mitral valve prolapse with regurgitation. Despite treatment with insulin, metformin, thyroxine, and statins, her health continued to deteriorate. In September 2021, she was diagnosed with late-onset glutaric aciduria type I and severe carnitine deficiency. Following the initiation of treatment with carnitine and riboflavin, her metabolic syndrome parameters showed improvement. Her genetic testing revealed a pathogenic variant in the GCDH gene. This case underscores the importance of exploring potential associations between metabolic syndrome and glutaric aciduria and assessing treatment outcomes. Further research in this area is warranted to enhance our understanding of these complex conditions and their interplay.