Fanconi Syndrome
Overview
Plain-Language Overview
Fanconi Syndrome is a condition that affects the kidneys, specifically the part called the proximal tubules. These tubules normally help the body reabsorb important substances like glucose, amino acids, phosphate, and bicarbonate from the urine back into the blood. In this syndrome, the tubules do not work properly, causing these substances to be lost in the urine. This leads to problems such as weak bones, dehydration, and electrolyte imbalances. The condition can result from inherited genetic problems or damage caused by toxins, medications, or diseases. It mainly affects the body's ability to maintain a healthy balance of minerals and nutrients, which is essential for overall health.
Clinical Definition
Fanconi Syndrome is a disorder characterized by generalized dysfunction of the proximal renal tubules, leading to impaired reabsorption of multiple solutes including glucose, amino acids, phosphate, bicarbonate, and uric acid. The core pathology involves defective transport mechanisms within the proximal tubule cells, which can be caused by inherited mutations (e.g., in HNF4A or mitochondrial DNA) or acquired insults such as exposure to toxins, drugs (e.g., ifosfamide, tenofovir), or systemic diseases like multiple myeloma. This results in renal tubular acidosis type 2, hypophosphatemia, and polyuria. Clinically, it manifests with symptoms related to electrolyte disturbances, bone demineralization (rickets or osteomalacia), and growth retardation in children. The syndrome is significant because it can lead to chronic kidney disease if untreated and requires identification of the underlying cause for management.