Disorders_of_Sex_Hormones_Flashcards
What are the findings in primary hypogonadism (Klinefelter’s syndrome)?
High LH, Low Testosterone
What are the findings in hypogonadotrophic hypogonadism (Kallman’s syndrome)?
Low LH, Low Testosterone
What are the findings in androgen insensitivity syndrome?
High LH, Normal/high Testosterone
What are the findings in a testosterone-secreting tumour?
Low LH, High Testosterone
What is Klinefelter’s syndrome associated with?
Karyotype 47, XXY
What are the features of Klinefelter’s syndrome?
Often taller than average, lack of secondary sexual characteristics, small, firm testes, infertile, gynaecomastia (increased incidence of breast cancer), elevated gonadotrophin levels
How is Klinefelter’s syndrome diagnosed?
Chromosomal analysis
What is Kallman’s syndrome?
A recognised cause of delayed puberty secondary to hypogonadotrophic hypogonadism, usually inherited as an X-linked recessive trait
What causes Kallman’s syndrome?
Failure of GnRH-secreting neurons to migrate to the hypothalamus
What is a key clue for diagnosing Kallman’s syndrome?
Lack of smell (anosmia) in a boy with delayed puberty
What are the features of Kallman’s syndrome?
‘Delayed puberty’, hypogonadism, cryptorchidism, anosmia, low sex hormone levels, inappropriately low/normal LH, FSH levels, normal or above average height
What additional features are seen in some patients with Kallman’s syndrome?
Cleft lip/palate and visual/hearing defects
What is androgen insensitivity syndrome?
An X-linked recessive condition due to end-organ resistance to testosterone causing genotypically male children (46XY) to have a female phenotype
What is the new term for testicular feminisation syndrome?
Complete androgen insensitivity syndrome
What are the features of androgen insensitivity syndrome?
‘Primary amenorrhoea’, undescended testes causing groin swellings, breast development may occur as a result of conversion of testosterone to oestradiol
How is androgen insensitivity syndrome diagnosed?
Buccal smear or chromosomal analysis to reveal 46XY genotype
What is the management for androgen insensitivity syndrome?
Counselling (raise child as female), bilateral orchidectomy (increased risk of testicular cancer due to undescended testes), oestrogen therapy
summarise disorders of sex hormones
Disorders of sex hormones
The table below summarises the findings in patients who have disorders of sex hormones:
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 amenorrhoea’
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
A 17-year-old girl presents to her GP because she is concerned that she hasn’t started menstruating yet. She is otherwise well in herself.
On examination, she is of normal height and has had breast development, but very little pubic hair. On examination of the abdomen you can feel two masses in the groin. Her external genitalia appear normal.
What is the most likely diagnosis?
Androgen insensitivity syndrome
Congenital adrenal hyperplasia
Kallman syndrome
Polycystic ovarian syndrome
Turner’s syndrome
Androgen insensitivity - classic presentation is ‘primary amenorrhoea’
Important for meLess important
This patient has androgen insensitivity, which means they are genetically XY but are phenotypically female due to reduced/absent testosterone receptors in target tissues. It is an X-linked disorder. The masses are due to undescended testes.
Congenital adrenal hyperplasia is not correct because this usually causes precocious puberty, and early onset of pubic hair, due to excess androgen production. Females with the condition usually have ambiguous genitalia and virilisation, whereas males have normal genitalia at birth.
Kallman syndrome can present with primary amenorrhoea in females. However, this would not explain the masses in the groin.
Polycystic ovarian syndrome is much more likely to cause secondary amenorrhoea or oligomenorrhoea rather than primary. It also would like present with other features, such as acne, hirsutism.
Turner’s also causes primary amenorrhoea, but they often have other features for example being short, webbed neck, and heart defects such as coarctation of the aorta. They would also not have normal breast development, and would not have undescended testes.
A 15-year-old teenage girl presents with delayed puberty, having not commenced her menses. She is well in her self generally, with no significant medical history.
On examination, she is of slim build, with small breasts. There is no pubic hair present. Her abdomen is soft and non-tender, though there are marble-sized groin swellings bilaterally.
What is the most likely explanation for this presentation?
Non-Hodgkin’s lymphoma
Imperforate hymen
Turner’s syndrome
Androgen insensitivity
Congenital adrenal hyperplasia
Androgen insensitivity
Androgen insensitivity - classic presentation is ‘primary amenorrhoea’
The key symptom here is the groin swellings, which combined with ‘primary amenorrhoea’ and no pubic hair points towards a diagnosis of androgen insensitivity (previously testicular feminisation syndrome). The groin swellings here are undescended testes. This is a condition in which the patient is genetically male (46XY), but phenotypically female. Feminisation is a result of increased oestradiol levels, which lead to breast development.
Non-Hodgkin’s lymphoma could explain the groin swellings, but would likely have systemic symptoms and is a less likely cause of delayed puberty.
Congenital adrenal hyperplasia would likely be diagnosed much earlier than puberty and is typically characterised by ambiguous genitalia and other symptoms of adrenal insufficiency, such as arrhythmias and vomiting.
Turner’s syndrome (45X0) would have other physical features mentioned, notably short stature, shield chest and webbing of the neck. These patients would be unlikely to have breast development.
