Edwards syndrome (trisomy 18)

What it is

Edwards syndrome is trisomy 18: the presence of an extra chromosome 18, karyotype 47,XX+18 or 47,XY+18. Incidence is about 1:6.000. It is the second most common autosomal trisomy after Down syndrome (trisomy 21), and the risk increases with maternal age.

How it presents

The hands and feet carry the signs that name it: rocker bottom feet, overlapping fingers, and clenched fists with flexion contractures.

The rest of the picture:

• Head and face: microcephaly, prominent occiput, low-set ears, malformed auricles, micrognathia, broad nose, cleft lip and palate, high palate.
• Body and tone: IUGR, intellectual disability, hypertonia, short sternum, limited hip abduction.
• Nails and nose: hypoplastic nails, hypoplastic nasal alae.
• Elsewhere: congenital heart defects, diaphragmatic hernia, and malformation of ureters and kidneys (horseshoe kidneys).

Talipes equinovarus, the club foot, is among its associations.