What Is Fanconi Syndrome?

Fanconi syndrome

Basic description of Fanconi syndrome

Fanconi syndrome is a hereditary or acquired disease. It is often associated with cystine disease and is characterized by abnormal renal tubular function that causes glucosuria, phosphate urine, amino acid urine, and bicarbonate. Saline urine.

Hereditary Fanconi syndrome is often accompanied by other hereditary diseases, especially cystine disease, which is an autosomal recessive genetic disease. Heterozygotes can show intracellular cystine deposition, but no other clinical and laboratory manifestations. Fanconi syndrome can also be accompanied by hepatolenticular nucleus, hereditary fructose intolerance, galactosemia, glycogen storage disease, tyrosinemia, and Lowe syndrome (eye-brain-renal syndrome) .

Acquired Fanconi syndrome can be caused by the use of 6-mercaptopurine or expired tetracycline, kidney transplantation, multiple myeloma, amyloidosis, poisoning by heavy metals or other chemicals, vitamin D deficiency, etc.

Multiple dysfunctions of the proximal tubule cause reduced glucose, phosphate, amino acid, bicarbonate, uric acid, water, potassium, and sodium reabsorption. Amino acid urine is common, but increased cystine secretion is not serious. Fundamental pathophysiology The change is unclear.

The main clinical symptoms of hereditary Fanconi syndrome are proximal tubular acidosis, hypophosphatemic rickets, hypokalemia, polyuria, and thirst-they can appear in infancy.

In the nephropathy type with cystine disease, growth retardation is common; retinal pigmentation is reduced in the retina. The development of interstitial nephritis can lead to progressive renal failure, which is fatal before puberty.

Adult patients with acquired Fanconi syndrome have abnormal renal tubular acidosis, hypophosphatemia, hypokalemia, and other laboratory tests. Patients may have symptoms of bone disease (osteoporosis) and muscle weakness.

Fanconi syndrome diagnosis basis

Diagnosis is based on abnormal renal function, especially the presence of glucosuria, phosphateuria, and amino aciduria. In patients with cystine disease, slit lamp examination can reveal the presence of cystine crystals in the cornea.

Fanconi Syndrome Treatment

Except for the targeted removal of nephrotoxic substances, there is no special treatment. Oral administration of sodium bicarbonate can reduce acidosis. Shohl solution of 2 ~ 3mEq / (kg.d) can also be administered, or 5 ~ 15ml can be taken after meals or before bedtime. Dicitrate or polycitrate to replace NaHCO3 solution is more acceptable. Potassium supplementation is required. See below for treatment of hypophosphatemic rickets. Kidney transplantation is feasible in patients with renal failure. But if cystine Disease is a major illness, and progressive damage to other organs will continue and eventually lead to death.