Currently, reliable methods for differentiating 21OHD from other forms of CAH are an adrenocorticotropic hormone (ACTH) stimulation test [16], urine steroid profile analyses using gas chromatography mass spectrometry [49], and genetic test, which cannot be used as a first-line diagnostic test because the procedure of CYP21A2 gene analysis is extremely complicated [50,51,52]. The gene discussed is POMC; the disease is congenital adrenal hyperplasia.