SIMIAN CREASE

Simian crease has been detected sonographically by Jeanty (1). A proper image can be obtained in about 20% of fetuses after 24 weeks once the art of detection has been perfected.

• The incidence of one simian crease is considered to be present in at least 50% of infants with trisomy 21, and in 4% of non-affected population.
• The chance of having trisomy 21 when a simian crease is found is about 1-2%.
• Other syndromes in which simian crease is an occasional finding (probably not detectable by ultrasound).
• Saethre Chotzen syndrome (cranio-oculo-dental syndrome).
• Fetal hydantoin syndrome.
• 18p syndrome.
• Coffin-Lowry syndrome.
• Noonan's syndrome
• KGB syndrome.
• XXXY, XXXXY, XXXXX syndromes.
• Larsen's syndrome

REFERENCES

1. Jeanty P. Prenatal detection of simian crease. J Ultrasound Med 1990;9:131-136.