Fanconi syndrome
De Toni-Fanconi-Debré syndromeFanconi syndrome is a disorder of the kidney tubes in which certain substances normally absorbed into the bloodstream by the kidneys are released into the urine instead.
Causes
Fanconi syndrome can be caused by faulty genes, or it may result later in life due to kidney damage. Sometimes the cause of Fanconi syndrome is unknown.
Common causes of Fanconi syndrome in children are genetic variations that affect the body's ability to break down certain compounds such as:
- Cystine (cystinosis)
-
Fructose (fructose intolerance)
Fructose intolerance
Hereditary fructose intolerance is a disorder in which a person lacks the protein needed to break down fructose. Fructose is a fruit sugar that natu...
Read Article Now Book Mark Article -
Galactose (galactosemia)
Galactosemia
Galactosemia is a condition in which the body is unable to use (metabolize) the simple sugar galactose.
Read Article Now Book Mark Article - Glycogen (glycogen storage disease)
Cystinosis is the most common cause of Fanconi syndrome in children.
Other causes in children include:
- Exposure to heavy metals such as lead, mercury, or cadmium
- Lowe syndrome, a rare genetic disorder of the eyes, brain, and kidneys
-
Wilson disease
Wilson disease
Wilson disease is an inherited disorder in which there is too much copper in the body's tissues. The excess copper damages the liver and nervous sys...
Read Article Now Book Mark Article - Dent disease, a rare genetic disorder of the kidneys
In adults, Fanconi syndrome can be caused by various things that damage the kidneys, including:
- Certain medicines, including azathioprine, cidofovir, gentamicin, and tetracycline
- Kidney transplant
- Light chain deposition disease
-
Multiple myeloma
Multiple myeloma
Multiple myeloma is a blood cancer that starts in the plasma cells in the bone marrow. Bone marrow is the soft, spongy tissue found inside most bone...
Read Article Now Book Mark Article -
Primary amyloidosis
Primary amyloidosis
Primary amyloidosis is a rare disorder in which abnormal proteins build up in tissues and organs. Clumps of the abnormal proteins are called amyloid...
Read Article Now Book Mark Article
Symptoms
Symptoms include:
- Passing large amounts of urine, which can lead to dehydration
- Excessive thirst
- Severe bone pain
- Fractures due to bone weakness
- Muscle weakness
Exams and Tests
Laboratory tests may show that too much of the following substances may be lost in the urine:
-
Amino acids
Amino acids
Amino acids are molecules that combine to form proteins. Amino acids and proteins are the building blocks of life. When proteins are digested or bro...
Read Article Now Book Mark Article - Bicarbonate
-
Glucose
Glucose
The glucose urine test measures the amount of sugar (glucose) in a urine sample. The presence of glucose in the urine is called glycosuria or gluco...
Read Article Now Book Mark Article - Magnesium
- Phosphate
-
Potassium
Potassium
The potassium urine test measures the amount of potassium in the urine.
Read Article Now Book Mark Article -
Sodium
Sodium
The sodium urine test measures the amount of sodium the urine. Sodium can also be measured in a blood sample.
Read Article Now Book Mark Article -
Uric acid
Uric acid
The uric acid urine test measures the level of uric acid in the urine. The uric acid blood level can be checked using a blood test.
Read Article Now Book Mark Article
Loss of these substances can lead to a variety of problems. Further tests and a physical exam may show signs of:
- Dehydration due to excess urination
- Growth failure
-
Osteomalacia
Osteomalacia
Osteomalacia is softening of the bones. It most often occurs because of a problem that leads to vitamin D deficiency, which helps your body absorb c...
Read Article Now Book Mark Article -
Rickets
Rickets
Rickets is a disorder caused by a lack of vitamin D, calcium, or phosphate. It leads to softening and weakening of the bones.
Read Article Now Book Mark Article -
Type 2 renal tubular acidosis
Type 2 renal tubular acidosis
Proximal renal tubular acidosis is a disease that occurs when the kidneys don't properly remove acids from the blood into the urine. As a result, to...
Read Article Now Book Mark Article
Treatment
Many different diseases can cause Fanconi syndrome. The underlying cause and its symptoms should be treated as appropriate.
Outlook (Prognosis)
The prognosis depends on the underlying disease.
When to Contact a Medical Professional
Contact your health care provider if you have dehydration or muscle weakness.
References
Bonnardeaux A, Bichet DG. Inherited disorders of the renal tubule. In: Yu ASL, Chertow GM, Luyckx VA, Marsden PA, Skorecki K, Taal MW, eds. Brenner and Rector's The Kidney. 11th ed. Philadelphia, PA: Elsevier; 2020:chap 44.
Chua AN, Kumar R, Foreman JW. Fanconi syndrome and other proximal tubule disorders. In: Johnson RJ, Floege J, Tonelli M, eds. Comprehensive Clinical Nephrology. 7th ed. Philadelphia, PA: Elsevier; 2024:chap 50.
-
Kidney anatomy - illustration
The kidneys are responsible for removing wastes from the body, regulating electrolyte balance and blood pressure, and the stimulation of red blood cell production.
Kidney anatomy
illustration
Review Date: 3/31/2024
Reviewed By: Todd Gersten, MD, Hematology/Oncology, Florida Cancer Specialists & Research Institute, Wellington, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.