Turner syndrome
Turner syndrome is characterised by gonadal dysgenesis and short stature. The diagnosis is confirmed by the karyotype 45 XO.
Baseline investigations - all patients
Full blood count
This is a useful indicator of general health and as a screen for underlying disease including coeliac's or hypopituitarism in a patient presenting with short stature and abnormal sexual development.
Urea and electrolytes
Useful screen for renal disease.
Liver function test
Useful indicator of general health and underlying disease.
Bone profile
Useful indicator of general health and underlying disease.
Glycosylated haemoglobin, fasting glucose and lipids
Diabetes has an increased incidence in Turner's syndrome.
Patients with Turner's syndrome also have an increased risk of renal and cardiovascular disease, and so cardiovascular risk modification is essential.
Karyotype
This should be performed at presentation in patients with absent puberty, and in all patients with suspected Turner’s, androgen insensitivity and Klinefelter’s syndrome. XO is the commonest karyotype encountered in Turner's syndrome, but mosaics and patients with partial deletions and other chromosomal abnormalities also occur.
Pituitary function
Growth hormone, Insulin like growth factor I
Patients with Turner's syndrome and severe short stature may benefit from GH therapy.
Prolactin
Hyperprolactinaemia may cause pubertal delay and hypogonadotropic hypogonadism.
9am cortisol
This is not usually assessed in patients with Turner's syndrome, though if a diagnosis of Cushing's is being considered, urinary free cortisols and a low dose dexamethasone suppression test should be arranged instead.
Estrodiol, sex hormone binding globulin
Estrodiol is usually low in Turner's syndrome.
Luteinising hormone, follicle stimulating hormone
LH and FSH should be checked in all patients presenting with hypogonadism.
Thyroid stimulating hormone, thyroxine
Thyroid dysfunction may lead to pubertal delay. Turner's syndrome is also associated with an increased incidence of thyroid disease.
Chest radiograph
Chest XR should be performed at diagnosis of Turner's as a simple screen for congenital abnormalities and coarctation of the aorta.
Further investigations - selected cases only
Electrocardiogram, echocardiogram
ECG and echocardiogram should be performed to seek coarctation of the aorta or other abnormalities in patients with confirmed Turner syndrome at diagnosis and subsequently three to five yearly.
Renal ultrasound scan
Ultrasound of the renal system is performed at diagnosis of Turner’s and Kallmann’s syndromes as anatomical abnormalities occur more frequently in people with these conditions.
Pelvic ultrasound scan
This is useful to perform in most patients presenting with absent or delayed puberty to identify and locate the gonads, and to assess uterine size prior to considering pregnancy in female patients.
Bone age
Consider performing plain radiograph to assess bone age in younger patients with delayed puberty.
Hearing test
This is performed every five years in people with Turner's syndrome.
Auto-antibody screen
Thyroid and coeliac antibodies should be assessed at diagnosis in patients with Turner's syndrome, due to an increased incidence of these disorders.
Bone densitometry scan
This should be considered in all patients with long standing hypogonadism. It may be useful to repeat after five years of treatment.
Vitamin D
Low serum vitamin D levels strengthen the case for vitamin D replacement therapy in patients with osteoporosis of any cause.