We report a female newborn with characteristic signs of Antley-Bixler syndrome (ABS) such as midface hypoplasia, radiohumeral synostosis and multiple joint contractures. The newborn also presented ambiguous genitalia, stage Prader V, and congenital adrenal hyperplasia. The mother experienced midterm virilization due to a pregnancy luteoma. Her elevated androgen levels and virilization symptoms normalized post partum without treatment. The newborn had elevated serum testosterone and 17-OH-progesterone levels which remained elevated because of a 21-hydroxylase deficiency. The child's treatment in order of priority was: hydrocortisone substitution, craniofacial/skeletal anomaly management and surgical correction of the external genitalia. Mutations in the genes for fibroblast growth factor (FGF) 8 and receptors FGFR1, FGFR2, and FGFR3 were not detected.
Conclusion: A newborn girl with manifestations of the Antley-Bixler syndrome showed severe virilization probably caused by the association of a mild 21-hydroxylase deficiency and maternal hyperandrogenism due to a pregnancy luteoma. Abnormalities of androgen metabolism may be responsible for virilization reported in other cases of the Antley-Bixler syndrome.