The molecular and genetic base of congenital transport defects

[...]genetic heterogeneity may be present in the first two diseases and the defects may not be identical in the kidney and intestine. [...]genetic control for the transport of this group of amino acids must be at four different sites at least. 3 Cystinuria is the most common congenital amino acid transport defect. The frequent log normal distribution of an enzymatic activity or transport capacity may be considered as the functional counterpart of the gene polymorphism. [...]for the future nutritional recommendations in a specific population it may be possible to include data on the polymorphism of genes coding for nutrient absorption.