Disorders of sex hormones
The table below summarises the findings in patients who have disorders of sex hormones:
Klinefelter's syndrome
Klinefelter's syndrome is associated with karyotype 47, XXY
Features
Diagnosis is by chromosomal analysis
Kallman's syndrome
Kallman's syndrome is a recognised cause of delayed puberty secondary to hypogonadotrophic hypogonadism. It is usually inherited as an X-linked recessive trait. Kallman's syndrome is thought to be caused by failure of GnRH-secreting neurons to migrate to the hypothalamus.
The clue given in many questions is lack of smell (anosmia) in a boy with delayed puberty
Features
Cleft lip/palate and visual/hearing defects are also seen in some patients
Androgen insensitivity syndrome
Androgen insensitivity syndrome is an X-linked recessive condition due to end-organ resistance to testosterone causing genotypically male children (46XY) to have a female phenotype. Complete androgen insensitivity syndrome is the new term for testicular feminisation syndrome
Features
Diagnosis
Management
| Disorder | LH | Testosterone |
|---|---|---|
| Primary hypogonadism (Klinefelter's syndrome) | High | Low |
| Hypogonadotrophic hypogonadism (Kallman's syndrome) | Low | Low |
| Androgen insensitivity syndrome | High | Normal/high |
| Testosterone-secreting tumour | Low | High |
Klinefelter's syndrome
Klinefelter's syndrome is associated with karyotype 47, XXY
Features
- often taller than average
- lack of secondary sexual characteristics
- small, firm testes
- infertile
- gynaecomastia - increased incidence of breast cancer
- elevated gonadotrophin levels
Diagnosis is by chromosomal analysis
Kallman's syndrome
Kallman's syndrome is a recognised cause of delayed puberty secondary to hypogonadotrophic hypogonadism. It is usually inherited as an X-linked recessive trait. Kallman's syndrome is thought to be caused by failure of GnRH-secreting neurons to migrate to the hypothalamus.
The clue given in many questions is lack of smell (anosmia) in a boy with delayed puberty
Features
- 'delayed puberty'
- hypogonadism, cryptorchidism
- anosmia
- sex hormone levels are low
- LH, FSH levels are inappropriately low/normal
- patients are typically of normal or above average height
Cleft lip/palate and visual/hearing defects are also seen in some patients
Androgen insensitivity syndrome
Androgen insensitivity syndrome is an X-linked recessive condition due to end-organ resistance to testosterone causing genotypically male children (46XY) to have a female phenotype. Complete androgen insensitivity syndrome is the new term for testicular feminisation syndrome
Features
- 'primary amennorhoea'
- undescended testes causing groin swellings
- breast development may occur as a result of conversion of testosterone to oestradiol
Diagnosis
- buccal smear or chromosomal analysis to reveal 46XY genotype
Management
- counselling - raise child as female
- bilateral orchidectomy (increased risk of testicular cancer due to undescended testes)
- oestrogen therapy