ACADM and hyperinsulinemic hypoglycemia, familial, 4: Congenital deficiency of the enzyme medium-chain acyl-CoA dehydrogenase (MCAD) (ICD-10: E71.3; OMIM: 201450) is one of the most common disorders of ß-oxidation in Germany with an prevalence of 1:10,607 (n = 75) in 2021 and 1:11,273 (n = 65) in 2022, according to the national screening reports [1–3].