Citrullinemia is classified as which type of disorder?

Citrullinemia is classified as an autosomal recessive urea cycle disorder that results from a defect in the urea cycle, specifically a deficiency in the enzyme argininosuccinate synthetase. This condition leads to the accumulation of ammonia and other toxic substances in the blood, which can cause serious neurological damage and metabolic disturbances if not promptly managed.

This classification as an autosomal recessive disorder means that an individual must inherit two copies of the mutated gene, one from each parent, in order to express the disease. This genetic aspect plays a vital role in understanding its inheritance patterns and potential risks for offspring.

The other choices refer to different categories of disorders that do not relate to citrullinemia. Metabolic disorders affecting carbohydrate metabolism and primary renal tubule dysfunction focus on very different biochemical pathways. A chromosomal disorder associated with Down syndrome involves an abnormal number of chromosomes rather than a specific enzyme deficiency. Thus, the accurate classification as an autosomal recessive urea cycle disorder provides a clear understanding of both the genetic nature and the biochemical impact of citrullinemia.