Turner’s syndrome only affects women, with about 1 in 2000 to 5000 girls born with it. A complete or partial lack of a sex chromosome results in a woman having “XO” rather than the usual “XX” complement of sex chromosomes.
Because part of the second X chromosome is sometimes present, there are variations in the syndrome. These include a wide range of symptoms, which can vary considerably from one person to the next. However, all women with Turner’s syndrome have some level of genetic abnormality which affects their fertility. Women with Turner’s syndrome have: i
- Primary amenorrhea (no menstrual bleeding).
- Premature ovarian failure.
- Infertility.
Testing
A chromosome (karyotype) test is definitive and will show the absence or reduction in one of the X chromosomes.
Treatment
Modern medical advances enable some women with Turner’s syndrome to get pregnant. Egg donation is needed as part of IVF as Turner’s syndrome women can’t produce mature eggs. Estrogen replacement therapy is also required to enable the uterus to support conception and pregnancy.
The Turner Syndrome Society’s website: www.tss.org.uk
Androgen Insensitivity Syndrome
Androgen Insensitivity Syndrome (AIS) is an uncommon condition that was previously called “testicular feminisation”. However, it causes 10% of primary amenorrhoea cases (a woman never has a period). The blueprint of all embryos is 90% female, and sex hormones released from the first trimester determine a baby’s sexual structure and function.
If the baby doesn’t respond to sex hormones during this time, it will be born looking like a girl but will lack the usual sexual structures and ability to conceive.
Androgens are predominantly male hormones such as testosterone. In AIS, the baby doesn’t have the usual sensitivity to male hormones, which causes abnormal sexual development for a boy or girl. Although a woman may look perfectly normal in all respects, she actually has the XY sex chromosomes that code for a man.
There are two ways this can happen:
- The baby has an absence of androgen receptors.
- The androgen receptors are present, but they fail to function correctly.
Either option will prevent or reduce the normal masculinisation of the sex organs in a developing XY male baby. The masculinising process normally starts in the seventh week of pregnancy when the differences on the Y chromosome triggers the release of androgen hormones, and their influence continues until a few months after birth.
Androgens change sex organs into a penis and testes. The genetic differences of an XX baby trigger the release of feminising hormones that promote the full development of the ovaries and womb. With AIS, there’s an absence of sexualisation at this critical stage.
Types of AIS
Three categories of AIS reflect the degree of masculinisation of the external genitals:
- Complete Androgen Insensitivity Syndrome (CAIS) is when the external genitalia are of a normal female.
- Partial Androgen Insensitivity Syndrome (PAIS) is when the external genitalia are partially (but not entirely) masculinised.
- Mild Androgen Insensitivity Syndrome (MAIS) is when the external genitalia are masculine.
Explaining the full consequences of AIS is beyond the scope of this article.
Testing
Karyotype testing (a chromosomal analysis) either confirms or excludes AIS.
The Androgen Insensitivity Syndrome Support Group (AISSG) website: www.aissg.org
Congenital Adrenal Hyperplasia
Congenital adrenal hyperplasia is an inherited disorder of the adrenal glands that affects about 1 in 10,000 to 18,000 newborn babies. Both sexes can be affected, but it has a much more significant impact on female fertility.
The critical issue is the lack of an enzyme needed by the adrenal glands to make cortisol and aldosterone hormones. A lack of cortisol and aldosterone triggers the body to produce more androgens (male sex hormones) to compensate, which causes male characteristics to appear early (or inappropriately) in life.
Symptoms
Boys may appear to enter puberty as early as 2-3 years of age and develop:
- A deep voice.
- The early appearance of pubic and armpit hair and the early development of male characteristics.
- An enlarged penis and small testes.
- Well-developed muscles.
Girls usually have normal female reproductive organs (ovaries, uterus and fallopian tubes), but they may also experience:
- Abnormal menstrual periods and/or a failure to menstruate.
- A deep voice.
- The early appearance of pubic hair, which may become generally excessive hair growth.
- Genitals that look both male and female (ambiguous genitalia) that often appear more male than female.
Both boys and girls will be tall as children, but as adults will be much shorter than average.
Testing
- Blood tests showing high levels of 17-OH progesterone and DHEA sulphate and low levels of aldosterone and cortisol. This indicates congenital adrenal hyperplasia and is usually accompanied by abnormal salt levels.
- Urine tests show abnormal salt levels, along with high levels of urinary 17-ketosteroids and low or normal levels of 17-hydroxycorticosteroids.
- X-rays will reveal bones that appear older than usual for that person’s age.
Treatment
Treatment involves daily cortisol (dexamethasone, fludrocortisone, or hydrocortisone) to return hormone levels to normal. Times of stress, severe illness or surgery often require additional medication.
Support groups
National Adrenal Diseases Foundation:www.medhelp.org/nadf/
The MAGIC Foundation:www.magicfoundation.org
The CARES Foundation:www.caresfoundation.org
