Biochemical monitoring of 21-hydroxylase deficiency: a clinical utility of overnight fasting urine pregnanetriol

PURPOSE OF REVIEW: 21-Hydroxylase deficiency (21-OHD), the most common form of congenital adrenal hyperplasia, is an autosomal recessive disorder caused by pathogenic variants in CYP21A2 . Although this disorder has been known for several decades, many challenges related to its monitoring and treatment remain to be addressed. The present review is written to describe an overview of biochemical monitoring of this entity, with particular focus on overnight fasting urine pregnanetriol. RECENT FINDINGS: We have conducted a decade-long research project to investigate methods of monitoring 21-OHD in children. Our latest studies on this topic have recently been published. One is a review of methods for monitoring 21-OHD. The other was to demonstrate that measuring the first morning PT level may be more practical and useful for biochemical monitoring of 21-OHD. The first morning pregnanetriol (PT), which was previously reported to reflect a long-term auxological data during the prepubertal period, correlated more significantly than the other timing PT in this study, with 17-OHP, before the morning medication. SUMMARY: In conclusion, although the optimal method of monitoring this disease is still uncertain, the use of overnight fasting urine pregnanetriol (P3) as a marker of 21-OHD is scientifically sound and may be clinically practical.