Updated: 8/12/2021

Aromatase Deficiency

Review Topic
  • A 1-day-old infant girl is born to a G1P1 mother who had no serious complications during pregnancy but notes that she developed facial hair, severe acne, and deepening of her voice in her second and third trimesters. On physical examination, the infant appears to have ambiguous genitalia. A karyotype reveals that the infant is 46,XX. Genetic testing reveals a mutation in the CYP19A1 gene.
  • Overview
    • aromatase deficiency is a disorder of sexual development characterized by decreased levels of estrogen and increased levels of testosterone
  • Epidemiology
    • incidence
      • < 1:1,000,000
      • fewer than 20 cases have been reported to date
  • Pathophysiology
    • mutation in the CYP19A1 gene, which codes for the enzyme aromatase
      • aromatase converts androgens to estrogens
      • ↓ aromatase activity leads to ↓ estrogen production and ↑ levels of androgens
  • Genetics
    • inheritance pattern
      • autosomal recessive
    • mutations
      • CYP19A1 gene
  • Symptoms
    • both sexes
      • hyperglycemia due to insulin resistance
    • females
      • lack of menstruation
      • lack of breast growth
  • Physical exam
    • females
      • infants
        • ambiguous genitalia in female infants
      • adolescence
        • acne
        • hirsutism
      • during pregnancy
        • maternal virilization 
          • excess fetal androgens may pass into the maternal bloodstream through the placenta
    • males
      • adolescence
        • abnormal sperm production
        • cryptorchidism
        • abnormal bone growth
  • Gene sequencing
    • will reveal a mutation in the CYP19A1 gene that codes for aromatase
  •  5α reductase deficiency
    • key distinguishing factor
      • 5α reductase deficiency is present only in genetic males (46,XY)
      • testosterone and estrogen levels are normal
  • Medical
    • estrogen replacement
      • leads to menses, breast develompent, and proper bone growth in females
      • allows for proper bone growth in males
  • Surgical
    • surgical modification of ambiguous genitalia in females

Please rate topic.

Average 5.0 of 2 Ratings

Private Note