Journal article Open Access

Mutations in MCT1 cDNA in patients with symptomatic deficiency in lactate transport

Merezhinskaya, Natalya; Fishbein, William N.; Davis, John I.; Foellmer, John W.

We identified 5 patients with subnormal erythrocyte lactate transport plus symptoms and signs of muscle injury on exercise and heat exposure. All had transport rates below the 95% envelope for normals. Three cases had rates 40–50% of mean normal. One was found to have a missense mutation in monocarboxylate transporter 1 (MCT1), the gene for the red cell lactate transporter (also expressed in skeletal muscle), at a conserved site, which was not mutated in a cohort of 90 normal humans. The other 2 cases had a different missense mutation (at a nonconserved site), which was also not mutated in the normal cohort. All 3 patients were heterozygotes. We presume that these mutations are responsible for their subnormal lactate transport, and hence their muscle injury under environmental stress; homozygous patients should be more seriously compromised. The other 2 cases had lactate transport rates 60–65% of mean normal, and their MCT1 revealed a third mutation, which proved to be a common polymorphism in the normal cohort. These 2 patients may be physiologic outliers in lactate transport, with their muscle damage arising from some other genetic defect.

Files (315.2 kB)
Name Size
315.2 kB Download
Views 64
Downloads 92
Data volume 29.0 MB
Unique views 64
Unique downloads 90


Cite as