Solution to Unknown Case #14 – Iliac Horn Syndrome or Nail Patella Syndrome or Hereditary Osteo-Onychodysplasia

History: 10 year old female with this Aunt Minnie finding on scout KUB for a retrograde voiding cystourethrogram.

Nail Patella Syndrome: Frontal KUB shows conspicuous iliac horns bilaterally (yellow circles). This finding is an Aunt Minnie for Iliac Horn syndrome, also called Nail Patella Syndrome or Hereditary Osteo-onychodysplasia.

This is a case of Iliac Horn Syndrome, also called Nail Patella Syndrome or Hereditary Osteo-Onychodysplasia. The finding in the image above of iliac horns is pathognomonic (an aunt minnie for Iliac Horn syndrome). The reason why it is called nail patella syndrome is demonstrated by the image below:

Nail Patella Syndrome: Lower extremity CT shows hypoplastic patella bilaterally, which are also dislocated superolaterally (white circles).

Nail patella syndrome is a congenital disorder seen in about 1 in 50,000 live births, and is caused by mutations in the LMX1B gene.  Nail-patella syndrome manifests as deformities of the nails, knees, pelvis, and elbows. Patients with this disorder are at risk for renal disease, which is why this young girl was undergoing a voiding cystourethrogram. Besides the three names already given, nail patella syndrome has also been referred to as Fong disease, osterreicher Syndrome, and Turner-Kieser Syndrome.