Which of the following enzyme deficiency of the Krebs-Henseleit urea cycle is X-linked dominant in inheritance?
High-Yield Explanation
The enzymes involved in INHERITED HYPERAMMONEMIAS are: 1. N-acetyl glutamate synthetase - Autosomal Recessive 2. Carbamyl phosphate synthetase (CPS) - Autosomal Recessive 3. Ornithine transcarbamylase (OTC) - X-linked dominant 4. Argininosuccinic acid synthetase (citrullinemia) - Autosomal Recessive 5. Argininosuccinase deficiency - Autosomal Recessive 6. Arginase deficiency - Autosomal Recessive The pattern of inheritance of each of these disorders is autosomal recessive except for OTC deficiency, which is X-linked dominant. Their clinical manifestations are a common expression of an accumulation of ammonia or of urea cycle intermediates in the brain; they differ only in severity, in accordance with the degree of completeness of the enzymatic deficiency and with the age of the affected individual. Ref: Ropper A.H., Samuels M.A. (2009). Chapter 37. Inherited Metabolic Diseases of the Nervous System. In A.H. Ropper, M.A. Samuels (Eds), Adams and Victor's Principles of Neurology, 9e.