Monocarboxylate transporter 8

Monocarboxylate transporter 8 (MCT8) is a is_associated_with::protein that in humans is encoded by the SLC16A2 is_associated_with::gene.

Function
MCT8 transports a variety of iodo-is_associated_with::thyronines including the thyroid hormones T3 and T4.

Clinical significance
A genetic disorder (discovered in 2003 and 2004 ) is caused by mutation in the transporter of thyroid hormone, MCT8, also known as SLC16A2, is believed to be account for a significant fraction of the undiagnosed neurological disorders (usually resulting in hypotonic/floppy infants with delayed milestones). This genetic defect was known as is_associated_with::Allan-Herndon-Dudley syndrome (since 1944) without knowing its actual cause. It has been shown mutated in cases of X-linked is_associated_with::leukoencephalopathy. Some of the symptoms for this disorder as are follows: normal to slightly elevated TSH, elevated T3 and reduced T4 (ratio of T3/T4 is about double its normal value). Normal looking at birth and for the first few years, hypotonic (floppy), in particular difficulty to hold the head, possibly difficulty to thrive, possibly with delayed myelination (if so, some cases are reported with an MRI pattern similar to is_associated_with::Pelizaeus-Merzbacher disease, known as PMD ), possibly with decreased mitochondrial enzyme activities, possibly with fluctuating lactate level. Patients have an alert face, a limited IQ, patients may never talk/walk, 50% need feeding tube, patients have a normal life span. This disease can be ruled out with a simple TSH/T4/T3 thyroid test.

Model organisms
is_associated_with::Model organisms have been used in the study of SLC16A2 function. A conditional is_associated_with::knockout mouse line, called Slc16a2tm1a(KOMP)Wtsi was generated as part of the is_associated_with::International Knockout Mouse Consortium program — a high-throughput mutagenesis project to generate and distribute animal models of disease to interested scientists.

Male and female animals underwent a standardized is_associated_with::phenotypic screen to determine the effects of deletion. Twenty one tests were carried out on is_associated_with::mutant mice and three significant abnormalities were observed. Female is_associated_with::homozygote mutants had decreased circulating glucose levels. Male is_associated_with::hemizygous mutants had an increased susceptibility to is_associated_with::bacterial infection. Both sexes had various abnormal plasma chemistry parameters.