Monocarboxylate transporter 8

Last updated
SLC16A2
Identifiers
Aliases SLC16A2 , DXS128, DXS128E, MCT 7, MCT 8, MCT7, MCT8, MRX22, XPCT, AHDS, solute carrier family 16 member 2
External IDs OMIM: 300095 MGI: 1203732 HomoloGene: 39495 GeneCards: SLC16A2
Orthologs
SpeciesHumanMouse
Entrez
Ensembl
UniProt
RefSeq (mRNA)

NM_006517

NM_009197

RefSeq (protein)

NP_006508

NP_033223

Location (UCSC) Chr X: 74.42 – 74.53 Mb Chr X: 102.74 – 102.87 Mb
PubMed search [3] [4]
Wikidata
View/Edit Human View/Edit Mouse

Monocarboxylate transporter 8 (MCT8) is an active transporter protein that in humans is encoded by the SLC16A2 gene. [5] [6] [7] [8]

Contents

Function

MCT8 actively transports a variety of iodo-thyronines including the thyroid hormones T3 and T4. [6]

Clinical significance

A genetic disorder (discovered in 2003 [6] and 2004 [9] ) 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 Allan–Herndon–Dudley syndrome (since 1944) without knowing its actual cause. It has been shown mutated in cases of X-linked leukoencephalopathy. [10] 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 Pelizaeus–Merzbacher disease, known as PMD [11] ), 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

Zebrafish

A knockout zebrafish line was generated in 2014 using the zinc-finger nuclease (ZFN)-mediated targeted gene editing system. [12] Similar to human patients, the zebrafish larvae exhibited neurological and behavioral deficiencies. They demonstrated reduced locomotor activity, altered myelin-related genes and neuron-specific deficiencies in circuit formation. [13]

Xenopus

Expression of mct8 has been characterised in Xenopus laevis [14] and Xenopus tropicalis . [15]

See also

Related Research Articles

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<span class="mw-page-title-main">Thyroid hormones</span> Hormones produced by the thyroid gland

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References

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  2. 1 2 3 GRCm38: Ensembl release 89: ENSMUSG00000033965 - Ensembl, May 2017
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  4. "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
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  12. Zada D, Tovin A, Lerer-Goldshtein T, Vatine GD, Appelbaum L (Sep 2014). "Altered behavioral performance and live imaging of circuit-specific neural deficiencies in a zebrafish model for psychomotor retardation". PLOS Genetics. 10 (9): e1004615. doi: 10.1371/journal.pgen.1004615 . PMC   4177677 . PMID   25255244.
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Further reading