A new marker for early diagnosis of 21-hydroxylase deficiency: 3β,16α,17α-trihydroxy-5α-pregnane-7,20-dione

Abstract

In neonates with 21-hydroxylase deficiency the specific marker 11-oxo-pregnanetriol is at low levels in the first days of life and this drives the search for alternatives. We describe the structural characterisation of a new early marker, 3β,16α,17α-trihydroxy-5α-pregnane-7,20-dione.Urine samples from 87 untreated and 11 recently treated newborns with 21-hydroxylase deficiency (42 males and 56 females) between birth and 40 days of age and control samples from 7 healthy neonates (4 males, 3 females) were compared. Steroids were analyzed as methyloxime-trimethylsilyl ether derivatives by GC–MS and GC–MS/MS, after extraction and enzymatic conjugate hydrolysis. Microchemical methods and deuterated derivatives were used.The new steroid was identified by comparison with 3β,16α,17α-trihydroxy-preg-5-en-20-one and 3β-hydroxy-5α-pregnane-7,20-dione standards. It was present for the first 4 weeks after birth (with a maximum around day 4) and showed a marked inter-individual variability. No effect of treatment was evident and levels were much higher than for 11-oxo-pregnanetriol in the first days of life. Only traces were found in controls.The likely involvement of oxysterol 7α-hydroxylase (CYP7B1) from the ‘acidic’ pathway of bile acid synthesis and 11β-hydroxysteroid dehydrogenase-1 in the generation of the 7-oxo group is discussed.We conclude that this steroid is a useful early marker of 21-hydroxylase deficiency.