Key Takeaways
- The prevalence of intersex traits in live births is estimated at 0.018% for cases requiring medical attention in the form of surgery, according to a study reviewing newborn screening data.
- Globally, congenital adrenal hyperplasia (CAH) affects approximately 1 in 14,000 to 1 in 18,000 newborns, making it the most common intersex variation.
- In the United States, the incidence of ambiguous genitalia at birth is about 1 in 4,500 live births based on hospital records from 1990-2010.
- CYP21A2 gene mutations account for 90-95% of CAH cases, with prevalence 1:15,000.
- In CAH, homozygous deletions or conversions in CYP21A2 occur in 20-30% of affected alleles.
- Androgen receptor (AR) gene mutations cause 80-90% of AIS cases, with over 1,000 variants identified.
- Patients with CAH show elevated 17-hydroxyprogesterone levels >1,000 ng/dL post-ACTH stimulation.
- In CAIS, serum testosterone levels are in male range (300-1,000 ng/dL) despite female phenotype.
- Klinefelter patients have 2-3 times higher gonadotropins (LH/FSH) and low-normal testosterone.
- 80-90% of classic CAH infants undergo genitoplasty by age 1 year in Western countries.
- Glucocorticoid replacement in CAH controls 17-OHP in 50-70% of patients long-term.
- Orchidopexy for undescended testes in DSD performed in 90% cases by age 18 months.
- Intersex individuals face 2-5 times higher rates of gender dysphoria diagnosis.
- 40% of intersex adults report dissatisfaction with childhood surgical decisions.
- In the US, only 20 states ban non-consensual intersex surgeries on minors as of 2023.
Intersex births are statistically rare but medically significant.
Genetics
Genetics Interpretation
Physiology
Physiology Interpretation
Prevalence
Prevalence Interpretation
Social
Social Interpretation
Treatments
Treatments Interpretation
Sources & References
- Reference 1NCBIncbi.nlm.nih.govVisit source
- Reference 2NICHDnichd.nih.govVisit source
- Reference 3PUBMEDpubmed.ncbi.nlm.nih.govVisit source
- Reference 4RAREDISEASESrarediseases.orgVisit source
- Reference 5TURNERSYNDROMEturnersyndrome.orgVisit source
- Reference 6ORPHAorpha.netVisit source
- Reference 7HRChrc.orgVisit source
- Reference 8ILGA-EUROPEilga-europe.orgVisit source
- Reference 9HUMANRIGHTShumanrights.gov.auVisit source
- Reference 10WHOwho.intVisit source
- Reference 11WILLIAMSINSTITUTEwilliamsinstitute.law.ucla.eduVisit source
- Reference 12DWdw.comVisit source
- Reference 13OHCHRohchr.orgVisit source
- Reference 14LEGISLATIONlegislation.govt.nzVisit source
- Reference 15GLAADglaad.orgVisit source
- Reference 16GOVgov.isVisit source
- Reference 17HRWhrw.orgVisit source
- Reference 18INTERACTADVOCATESinteractadvocates.orgVisit source
- Reference 19DEFENSEdefense.govVisit source
- Reference 20ENen.wikipedia.orgVisit source






