A rare acquired or inherited condition involving a generalized transport defect within the proximal tubules of the kidneys leading to renal losses of glucose, phosphate, calcium, uric acid, amino acids, and bicarbonates. The clinical features include short stature, osteomalacia, and renal failure. Variants of Fanconi Syndrome are determined by how they affect the proximal tubule and its resulting complications. The loss of bicarbonate results in Type 2 Fanconi Syndrome often classified as “proximal renal tubular acidosis.” The loss of phosphate results in rickets and osteomalacia.
Lignac De Toni Debré Syndrome; Fanconi Syndrome; Renal Fanconi Syndrome; Fanconi Renal-Tubular Syndrome.
It is named after Guido Fanconi (1892-1979), a Swiss pediatrician, who is regarded as one of the founders of modern pediatrics. In 1927, he described the hereditary panmyelopathy condition associated with short stature and hyperpigmentation that is better known as the Fanconi Anemia. In 1945, he founded the Helvetica Paediatrica Acta, which is an established international periodical. However, the present medical condition should not be confused with Fanconi Anemia, which is a separate disease. De Toni Debré Fanconi Syndrome included various scientists, including George Otto Emil Lignac (1891-1954), a Dutch pathologist-anatomist, who contributed to its study.
Genetic disorder but also can be caused by inborn errors of metabolism, Wilson disease, Lowe Syndrome, cystinosis, glycogenoses, hereditary fructose intolerance, mitochondrial diseases, heavy-metal poisoning, glue sniffing, and toxicity from some chemotherapeutic drugs.
Inherited form is estimated to occur in approximately 1:40,000 live births in the general population.
It is inherited as autosomal dominant, but a possible autosomal recessive and X-linked transmission has been reported. The gene involved in this process is located on the 15q15.3.
Syndrome may be inherited (idiopathic familial), secondary to other genetic diseases or secondary to exposure to certain toxins. Cystinosis is the most common genetic cause in childhood. Others are galactosemia, Wilson disease, tyrosinemia, and glycogen storage diseases. Toxins include heavy metals such as cadmium, lead, and mercury, ifosfamide, gentamicin, expired tetracycline, and various solvents. The disease causes failure of proximal renal tubular reabsorption.
Diagnosis is mainly clinical and biochemical. The presenting symptoms are polyuria, polydipsia, and dehydration. The biochemical findings are glucosuria with normal glycemia, hypophosphatemia, hyperaminoaciduria, acidosis, uricosuria, proteinemia, progressive renal insufficiency, and renal sodium and potassium wasting. Following the diagnosis of renal tubular acidosis, an underlying cause should be sought with appropriate investigations for inborn metabolic disease or environmental exposure.
Excessive renal loss of glucose, amino acids, potassium, bicarbonate, phosphate, calcium, water, and magnesium lead to growth retardation/dwarfism, polyuria, polydipsia, metabolic acidosis, ...