In this condition there is only one X chromosome in the female.
- 95% of cases result in spontaneous miscarriage
- Present in 1 in 5000
- Generalised oedema (hydrops)
- Nuchal thickening / fat pad
- Many appear completely normal
- Peripheral oedema
- Webbed neck
- Low posterior hairline
- Shortening of the 4th metacarpal
- Nipples widely spaced
- Coarctation of the aorta
- Intelligence is normal
- Social skills and some other high functional skills may be altered
- The bell curve for IQ is thought to be slightly to the left
- Short stature – usually seen in childhood from age 5 onwards. Growth hormone therapy can help reduce the deficit. Without therapy, the average height is 145cm.
- this is thought to be related to a lack of the SHOX gene
- Ovarian defects – often resulting in infertility. Pregnancy is still possible with IVF and donated ova.
- Pigmented moles
- Wide carrying angle of the arm
- Recurrent otitis media
- Delayed puberty
- Growth hormones to avoid short stature
- Offered from the age of 3 onwards
- No good if epiphyseal plates have already fused
- Oestrogen at pubertal age to ensure development of secondary sexual characteristics. Infertillity still usually persists.
- 50% of cases are (45,X)
- In 80% of these cases the defect is due to the loss of either an X or Y during paternal meiosis.
- In most other cases, there is deletion of part of or all of one of the arms of chromosome X.
- in some cases, there is considerable mosaicism, and thus there is a normal cell line in many of the patient’s cells (46, XX). These patients have a good chance of being fertile