Mondo Description Valinemia is a very rare metabolic disorder characterized by abnormally high levels of the amino acid valine in the blood and urine.Infants with valinemia reportedly experience lack of appetite, vomiting, and failure to thrive. In some cases, the condition may be life-threatening. Low muscle tone (hypotonia), excessive drowsiness, hyperactivity, and developmental delay have also been reported. Valinemia is caused by a deficiency of the enzymevaline transaminase, which is needed for the breakdown (metabolism) of valine in the body. It is inherited in an autosomal recessive manner, although the gene responsible for the condition is not yet known. Treatment includes adiet low in valine (introduced during early infancy) which usually improves symptoms and brings valine levels to normal.