| Testicular DSD (46,XX) | The gonade of a baby in the womb develop as testes, often because of the 'translocation' of the SRY gene from the Y to the X chromosome. This means that, prior to fertilisation, the SRY gene in the one fertilising sperm 'breaks off' the Y chromosome and 'attaches' itself to another chromosome (usually the X). And the presence of the SRY gene then kickstarrs the development of the gonads as testes. | 1 20 000 men |
| Ovotesticular DSD (46,XX) | The gonads of a baby in the womb develop as ovotested (this means part ovary and part testis). There may be differences in the amount of testis and ovary tissue on the left and right sides | 1/100 000 |
| Congenital Andrenal Hyperplasia 21-OHD (Majority of people with 46, XX CAH) |
A baby in the womb will develop ovaries and typical femal reproductive organs. Baby has a reduced function of the 21-hyroxylase enzyme resulting in an increased production of androgens by the adrenal glands. This will sometimes affect the size of the clitoris of a newborn baby. Children often develop adrenal insufficinecy and salt-loss a few days/weeks after birth. For more information and support, please visit the Living with CAH support group (UK.) |
1/30 000 (46,XX children) |
| Congenital Andrenal Hyperplasia 11-beta-hydroxylase |
A baby in the womb has a reduced function of the 11-hydroxylase enzyme resulting in an increased porduction of androgens by the adrenal glands. Because of an imbalance in adrenal hormones, childern can develop high blood pressure with age. For more information and support, please visit the Living with CAH support group (UK.) |
Rare (except in certain geographical areas) |
| Mayer-Rokitansky-Kuster Hauser (MRKH) syndrome |
Women who have typical ovarian development and typical genitalia. The womb (uterus) and upper part of the vagina do not develop. There are various dedicated MRKH information and support groups. |
1/4000-5000 women |
Overview produced by Ellie Magritte for dsdfamilies and based on earlier work by Charmian Quigley for dsdfamilies and by Nina Callens for www.idem.be.
With scientific input from John Achermann (UCL/GOSH London), for which our sincerest thanks.
We are also grateful to Martine Cools (UZGhent, Belgium), Nils Krone (UofSheffield), Justin Davies (UHSouthampton) and Martina Rodie (Scottisch Clinical DSD Network) for further input and review.
For any comments and suggestions please contact Ellie at info@dsdfamilies.org
To reference, please use: Overview of differences of sex development, dsdfamilies/Magritte, www.dsdfamilies.org, 2019
