Citrullinemia-is one of several human diseases caused by a defect in the KrebsHenseleit urea cycle. In this disorder a deficiency of liver argininosuccinate synthetase has been reported.' 1\Iorrow and his colleagues have recently described an infant with this condition2 and a fibroblast-like cell line has been derived from a skin biopsy of this child. In studying minimal media requirements for ...
