Turner syndrome screening

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Akash Daswaney, M.B.B.S[2]

Screening for complications of Turner syndrome starts as early as a prenatal visit. Abnormal maternal serum screening tests or an ultrasound detecting structural anomalies such shortened limbs, cystic hygromas, congenital heart defects or increased swelling of the hands or feet may point towards a diagnosis of Turner syndrome. As the years progress, screening involves a multidisciplinary combination of lab investigations (such as serum gonadotrophins, liver function tests, renal function tests, etc), referral to other departments (cardiology, endocrinology, ophthalmology, etc) and tools such as DEXA scans, X-rays, echocardiography, etc.

• The ‘Diagnostic study of choice’ page in this microchapter helps to integrate the below screening modalities in a clinical setting.
• In addition, frequent referral to departments such as cardiology, nephrology, embryology, genetics, endocrinology, otorhinolaryngology, ophthalmology, dermatology and rheumatology ensures that a detail physical examination can be done to catch early signs of associated conditions seen in Turner syndrome.
• Screening newborns usually first involves a bed side ultrasonography which may reveal nuchal translucency, structural abnormalities such as shortened limbs, lymphedema of hands and feed, cystic hygroma and cardiac defects.
• This is used along with a maternal serum screening test which detects high inhibin B, low unconjugated estriol, high human chorionic gonadotrophin and low alpha feto protein.
• Once a diagnosis has been established, screening is aimed at detecting complications.
• Individuals on growth hormone should be screened regularly with forward bend tests and X-rays as the therapy exposes underlying scoliosis.
• echocardiography for cardiac structural abnormalities especially aortic dilation that predisposes the individual to aortic dissection and sudden cardiac death.
  • The aortic severity index is a useful prognostic indicator when assessing for the risk of aortic dilatation. ^[1]
  • It is the aortic diameter corrected for body surface area and a score of more than 2.3 cm per metre square indicates a high risk of aortic dissection (2-2.3 cm per metre square is considered as moderate risk).
  • The advice offered to moderate risk patients is restriction of activities and that offered to high risk patients is that they should completely avoid competitive sports and intensive weight training.
• Renal ultrasound for structural abnormalities like duplication of the collecting system and horseshoe shaped kidney.
• Dual energy x-ray absorptiometry (DEXA) scans may be done to test bone mineral density.
• Audiology for sensorineural and conductive hearing loss.
• Multidisciplinary neuropsychiatric evaluation should be done at major transitional stages such preschool entry and high school entry. ^[2]
• ECGs should be performed as long QT syndrome frequently occurs secondary to medication used to treat complications of Turner syndrome.
• Individuals with a Y karyotypic abnormality should be screened with fluorescent insitu hybridization and polymerase chain reaction techniques, to detect the risk of developing a gonadoblastoma.

• Laboratory investigations that may help in screening include: ^[3]
  1. serum gonadotrophins and anti Mullerian hormone– ovarian reserve.
  2. renal function tests – renal failure secondary to structural abnormalities.
  3. Thyroid function tests – thyroiditis, hypothyroidism, hyperthyroidism
  4. liver function tests – focal nodular hyperplasia
  5. serum IgA, IgA anti endomysium antibodies and IgA antigliadin antibodies – Celiac disease
  6. Lipid profile – hyperlipidemia
  7. Oral glucose tolerance test and serum glycosylated hemoglobin – for type 2 diabetes mellitus.
  8. serum 25-hydroxyvitamin D- Vitamin D deficiency.

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