Frequency
The prevalence of aromatase deficiency is unknown; approximately 20 cases have been described in the medical literature.
Causes
Mutations in the CYP19A1 gene cause aromatase deficiency. The CYP19A1 gene provides instructions for making an enzyme called aromatase. This enzyme converts a class of hormones called androgens, which are involved in male sexual development, to different forms of estrogen. In females, estrogen guides female sexual development before birth and during puberty. In both males and females, estrogen plays a role in regulating bone growth and blood glucose levels. During fetal development, aromatase converts androgens to estrogens in the placenta, which is the link between the mother's blood supply and the fetus. This conversion in the placenta prevents androgens from directing sexual development in female fetuses. After birth, the conversion of androgens to estrogens takes place in multiple tissues.
CYP19A1 gene mutations that cause aromatase deficiency decrease or eliminate aromatase activity. A shortage of functional aromatase results in an inability to convert androgens to estrogens before birth and throughout life. As a result, there is a decrease in estrogen production and an increase in the levels of androgens, including testosterone. In affected individuals, these abnormal hormone levels lead to impaired female sexual development, unusual bone growth, insulin resistance, and other signs and symptoms of aromatase deficiency. In women who are pregnant with an affected fetus, excess androgens in the placenta pass into the woman's bloodstream, which may cause her to have temporary signs and symptoms of aromatase deficiency.
Inheritance
This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.
Other Names for This Condition
- 46,XX disorder of sex development (DSD) due to placental aromatase deficiency
- Estrogen synthetase deficiency
- Oestrogen synthetase deficiency
- Placental aromatase deficiency
Additional Information & Resources
Genetic Testing Information
Genetic and Rare Diseases Information Center
Patient Support and Advocacy Resources
Catalog of Genes and Diseases from OMIM
Scientific Articles on PubMed
References
- Baykan EK, Erdogan M, Ozen S, Darcan S, Saygili LF. Aromatase deficiency, a rare syndrome: case report. J Clin Res Pediatr Endocrinol. 2013;5(2):129-32. doi: 10.4274/Jcrpe.970. Erratum In: J Clin Res Pediatr Endocrinol. 2013 Sep 10;5(3):216. Citation on PubMed or Free article on PubMed Central
- Belgorosky A, Guercio G, Pepe C, Saraco N, Rivarola MA. Genetic and clinical spectrum of aromatase deficiency in infancy, childhood and adolescence. Horm Res. 2009;72(6):321-30. doi: 10.1159/000249159. Epub 2009 Oct 21. Citation on PubMed
- Bulun SE. Aromatase and estrogen receptor alpha deficiency. Fertil Steril. 2014 Feb;101(2):323-9. doi: 10.1016/j.fertnstert.2013.12.022. Citation on PubMed or Free article on PubMed Central
- Ludwikowski B, Heger S, Datz N, Richter-Unruh A, Gonzalez R. Aromatase deficiency: rare cause of virilization. Eur J Pediatr Surg. 2013 Oct;23(5):418-22. doi: 10.1055/s-0032-1324798. Epub 2012 Oct 23. No abstract available. Citation on PubMed
- Rochira V, Carani C. Aromatase deficiency in men: a clinical perspective. Nat Rev Endocrinol. 2009 Oct;5(10):559-68. doi: 10.1038/nrendo.2009.176. Epub 2009 Aug 25. Citation on PubMed
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