Most people have 23 pair of chromosomes for a total of 46.
22 pair are autosomes (any chromosome that is not a sex chromosome – example growth, appearance, metabolism).
1 pair are sex chromosomes (XX or XY in most cases).
The numbers in the table below indicate the total number of chromosomes.
SUMMARY
|
Total number of people whose bodies differ from standard male or female |
one in 100 births |
|
Total number of people receiving surgery to “normalize” genital appearance |
one or two in 1,000 births |
BREAKDOWN OF SOME INTERSEX CONDITIONS AND THEIR PREVALENCE
There may be at least 30-40 distinct intersex variations, with some sources identifying over 60-70 specific conditions.
Chromosomal Variations (e.g., Klinefelter Syndrome, Turner Syndrome, Mosaicism)
Gonadal Variations (e.g., Ovotesticular Disorder, Dysgenesis)
Hormonal Variations (e.g., Androgen Insensitivity Syndrome, Congenital Adrenal Hyperplasia)
Anatomical Variations (e.g., Ambiguous Genitalia, Hypospadias)
|
Intersex Trait (genotype) |
Prevalence |
|---|---|
|
Not XX, XY, Klinefelter or Turner |
one in 1,500 – 2,000 births (0.07 – 0.05%) |
|
Klinefelter Syndrome (47, XXY) |
one in 1,000 births (0.10%) |
|
Turner Syndrome (45, X) |
one in 2,710 births (0.04%) |
|
Androgen Insensitivity Syndrome (46, XY) |
one in 13,000 births (0.008%) |
|
Partial Androgen Insensitivity Syndrome (46, XY) |
one in 130,000 births (0.0008%) |
|
Classical Congenital Adrenal Hyperplasia (46, XY or 46, XX) |
one in 13,000 births (0.008%) |
|
Late Onset Adrenal Hyperplasia (46, XY or 46, XX) |
one in 50 – 1,000 births ( 2 – 0.1%) |
|
Vaginal Atresia (46, XX) |
one in 6,000 births (0.017%) |
|
Ovotestes (45, X / 46, XY mosaicism) |
one in 83,000 births (0.0012%) |
|
Idiopathic (no discernible medical cause (46, XY or 46, XX) |
one in 110,000 births (0.0009%) |
|
Iatrogenic (caused by medical treatment, eg progestin administered to pregnant mother – 46, XY or 46, XX) |
no estimate |
|
5 Alpha Reductase Deficiency (46, XY) |
no estimate |
|
Mixed Gonadal Dysgenesis (45, X or 46, XY mosaicism) |
no estimate |
|
Müllerian Agenesis (of vagina, ie MRKH Syndrome – 46, XX) |
one in 4,500 – 5,000 births (0.022 – 0.020%) |
|
Complete Gonadal Dysgenesis (46, XY or 46, XX or 45, X or 46, XY mosaicism) |
one in 150,000 births (0.00067%) |
|
Hypospadias (urethral opening in perineum or along penile shaft) |
one in 2,000 births (0.05%) |
|
Hypospadias (urethral opening between corona and tip of glans penis) |
one in 770 births (0.13%) |