Fanconi syndrome

Fanconi syndrome (also known as Fanconi's syndrome) is a disorder in which the proximal tubular function of the kidney is impaired, resulting in decreased reabsorption of electrolytes and nutrients back into the bloodstream. Compounds involved include glucose, amino acids, uric acid, phosphate and bicarbonate.

The reduced reabsorption of bicarbonate results in type 2 or proximal renal tubular acidosis, which may in some cases exist on its own, or more usually in combination with the Fanconi syndrome.

It is named after Guido Fanconi, a Swiss pediatrician; this may be a misnomer since Fanconi himself never identified it as a syndrome.

It should not be confused with Fanconi anemia, a separate disease.

Clinical features
Are the clinical features of proximal renal tubular acidosis:
 * Polyuria, polydipsia and dehydration
 * Rickets (in children) and osteomalacia (in adults)
 * Growth failure
 * Acidosis
 * Hypokalemia

And the other features of the generalised proximal tubular dysfunction of the Fanconi syndrome
 * Hypophosphatemia/Phosphaturia
 * Glycosuria
 * Proteinuria/Aminoaciduria
 * Uricosuria

Causes
There are different diseases underlying Fanconi syndrome. They can be inherited/congenital as well as acquired. Cystinosis is the most common cause of Fanconi syndrome in children; however, it is possible to acquire this disease later on in life. Other recognised causes of Fanconi's syndrome are Wilson's disease (a genetically inherited condition of copper metabolism), fructose intolerance, ingesting expired tetracyclines, and as a side effect of tenofovir.

Treatment
Treatment of children with Fanconi syndrome mainly consists of replacement of substances lost in the urine (mainly fluid and bicarbonate).