Use

Monitoring effectiveness of treatment in patients with phosphomannomutase 2 deficiency (PMM2‑CDG); establishing a baseline level prior to initiating treatment for PMM2‑CDG; this test is not useful for diagnosing congenital disorders of glycosylation (CDG) in general or PMM2‑CDG in particular. In many patients with PMM2‑CDG, the urine polyols sorbitol and mannitol are elevated relative to controls; sorbitol correlates with more severe disease and peripheral neuropathy. Both analytes may be increased in mild liver dysfunction. Recent trials suggest treatment with the aldose reductase inhibitor epalrestat can normalize sorbitol and mannitol levels. Quantitative results are reported without added interpretation. (Also used in SORD deficiency contexts.)