Nail-patella syndrome
Updates to Article Attributes
Nail-patella syndrome, also known as Fong disease, is a rare autosomal dominant condition which results from a symmetrical meso and ectodermal abnormalities.
Clinical presentation
Clinically the key feature is absent/hypoplastic nails from birth. Individuals may have flexion contractures and recurrent knee dislocations.
Associations
- renal dysfunction 5
Pathology
The underlying genetic defect is caused by loss of function mutations in the transcription factor LMX1B on chromosome 9 5-6.
Radiographic features
Plain radiograph
Diagnostic radiographic findings include:
- absent/hypoplastic patellae (with a tendency to recurrent dislocation)
- hypoplasia of the radial head or capitellum (leading to subluxation/dislocation)
- bilateral posterior iliac horns ("Fong's prongs")
- protuberant anterior iliac spines
The bilateral posterior iliac horns are due to exostoses arising from the posterior aspect of the iliac bones are present in as many as 80% of patients; this finding is considered pathognomonic for the syndrome. Other features include:
- scoliosis
- genu valgum deformity
- flared iliac crests
- open angle glaucoma 6
Differential diagnosis
For absent patella(e), consider:
History and etymology
Iliac horns were described by Edward Everett Fong (b. 1912), an American radiologist.
-<p><strong>Nail-patella syndrome</strong>, also known as <strong>Fong disease</strong>, is a rare <a href="/articles/autosomal-dominant">autosomal dominant</a> condition which results from a symmetrical meso and ectodermal abnormalities.</p><h4>Clinical presentation</h4><p>Clinically the key feature is absent/hypoplastic nails from birth. Individuals may have flexion contractures and recurrent knee dislocations.</p><h5>Associations</h5><ul><li>renal dysfunction <sup>5</sup>- +<p><strong>Nail-patella syndrome</strong>, also known as <strong>Fong disease</strong>, is a rare <a href="/articles/autosomal-dominant">autosomal dominant</a> condition which results from symmetrical meso and ectodermal abnormalities.</p><h4>Clinical presentation</h4><p>Clinically the key feature is absent/hypoplastic nails from birth. Individuals may have flexion contractures and recurrent knee dislocations.</p><h5>Associations</h5><ul><li>renal dysfunction <sup>5</sup>
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