Amelogenesis imperfecta nephrocalcinosis

Other Names: Enamel renal syndrome; ERS; Absent enamel, nephrocalcinosis and apparently normal calcium metabolism; Generalized enamel hypoplasia and renal dysfunction

A extremely rare, genetic malformation syndrome characterized by hypoplastic amelogenesis imperfecta (hypoplastic dental enamel) and nephrocalcinosis (precipitation of calcium salts in renal tissue).

Oral manifestations include yellow and misshaped teeth, delayed tooth eruption, and intrapulpal calcifications. Nephrocalcinosis is often asymptomatic but can progress during late childhood or early adulthood to impaired renal function, recurrent urinary infections, renal tubular acidosis, and rarely to end-stage renal failure.

Cause

This condition is caused by mutations in the FAM20A gene. This gene encodes a protein - the Golgi apparatus associated secretory pathway pseudokinase. The gene is located on the long arm of chromosome 17 (17q24.2).

Signs and symptoms

For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. 80%-99% of people have these symptoms

• Abnormal calcium-phosphate regulating hormone level
• Amelogenesis imperfecta
• Delayed eruption of teeth(Delayed eruption)
• Gingival overgrowth(Gum enlargement)
• Increased circulating osteocalcin level
• Nephrocalcinosis(Too much calcium deposited in kidneys)
• Nephropathy
• Yellow-brown discoloration of the teeth(Yellow-brown discolored teeth)

30%-79% of people have these symptoms

• Enuresis
• Hypocalciuria(Low urine calcium levels)
• Hypophosphaturia
• Impaired renal concentrating ability
• Renal insufficiency(Renal failure)

Diagnosis

The diagnosis may be suspected on the basis of the constellation of clinical features. It is made by sequencing the FAM20A gene. This condition is usually diagnosed in childhood but may not be recognised until early adulthood. The diagnosis is suspected on the combination of nephrocalcinosis and dental abnormalities.

Differential diagnosis

• Epidermolysis bullosa
• Jalili syndrome
• Raine syndrome
• Tricho-dento-osseous syndrome

Treatment

There is no specific treatment for this condition currently known and management of its various features is the norm.

NIH genetic and rare disease info

• NIH info on Amelogenesis imperfecta nephrocalcinosis

Amelogenesis imperfecta nephrocalcinosis is a rare disease.

Amelogenesis imperfecta nephrocalcinosis Resources
Latest articles Most recent articles Ongoing trials	Wikipedia