Lightwood Syndrome

Transient renal tubular acidosis in infants.

Distal Renal Tubular Acidosis; Transient Renal Tubular Acidosis (Infantile form).

Defect in urinary acidification with a reduction in urinary secretion of titratable acid and ammonium associated with bicarbonate wasting. By definition, this condition is transient and may be characterized by distal renal tubular acidosis (with or without bicarbonate wasting) and proximal renal tubular acidosis. Typical biochemical findings include acidemia, which may be severe, hyperchloremia, and marked base deficit. The severe acidosis may induce hyperparathyroidism, which in turn results in hypercalcemia.

The typical clinical picture, in association with the following biochemical changes, is used to make the diagnosis: metabolic acidosis, hyperchloremia, hyperparathyroidism and hypercalcemia, large base deficit, high urinary pH, and reduced renal excretion of titratable acid. Treatment with alkali replacement results in an improvement in the hyperchloremia and hypercalcemia. The transient need for alkali replacement therapy distinguishes this condition from other forms of renal tubular acidosis in which lifelong treatment may be required.

Lightwood syndrome occurs in neonates and is a self-limiting condition that rarely requires treatment beyond 18 months. Males are most commonly affected. Clinical findings include lethargy and reduced muscle tone, vomiting, constipation, anorexia, failure to thrive, polyuria, polydipsia, wasting. The clinical and biochemical findings are reversed by the administration of alkali (up to 25 mEq/kg/day). Nephrocalcinosis may be a feature, particularly in untreated patients. Gastroenteritis associated with prolonged dehydration may mimic the biochemical findings.

Clinical evaluation should confirm the absence of any clinical findings in adequately treated patients. Evaluate serum acid-base and electrolyte status. Serum calcium and parathyroid hormone activity should be normal. Evaluate renal function, particularly if there is a history of renal calculi.

Electrolyte and intravascular fluid status must be corrected prior to administration of anesthesia.

No known specific considerations.

Others diseases associated with renal tubular acidosis are as follows:

De Toni Debré Fanconi Syndrome: Rare acquired or inherited condition involving a generalized transport defect in the proximal tubules with renal losses of glucose, phosphate, calcium, uric acid, amino acids, and bicarbonates leading to short stature, osteomalacia, and renal failure.

Periodic Paralysis (PP): Congenital abnormality in membrane electrolyte conductance leading to episodic muscle weakness.

Albright-Butler Syndrome: Patients present with renal tubular acidosis, nephrocalcinosis, and renal failure. Hypokalemia with muscle weakness and periodic paralysis is frequent. Polyuria, vomiting, and dehydration lead to fluid and electrolyte imbalances.

Adenosine Deaminase Deficiency: Heterogeneous systemic disorder caused by the deficiency of adenosine deaminase resulting primarily in severe combined (cellular and humoral) immunodeficiency but also systemic abnormalities.

Gitelman Syndrome: Inherited renal tubular defect resulting in urinary loss of magnesium, sodium, potassium, and chloride with otherwise normal kidneys.

Lowe Syndrome: Genetically transmitted polymalformative syndrome characterized by the association of ocular problems with renal dysfunction and mental retardation.

Phosphoenolpyruvate Carboxykinase Deficiency: Congenital metabolic disease leading to a defect in gluconeogenesis.

Propionic Acidemia: Inborn error of metabolism affecting the mitochondrial catabolism of valine and isoleucine that, left untreated, results in ketoacidosis, lethargy, coma, and finally death.

Pyruvate Carboxylase Deficiency: Mitochondrial disease impairing synthetic pathways and leading to hypoglycemia and severe lactic acidosis.

Tyrosinemia: Elevated blood tyrosine levels are present in several clinical entities. The term tyrosinemia is used to describe several syndromes. In general, the association of liver and renal failure, marked edema, epistaxis, and distinctive cabbage-like odor are characteristic of the disease.