These findings support the hypothesis that the severe psychomotor retardation and elevated serum T(3) levels in these patients are caused by inactivation of the MCT8 transporter, preventing action and metabolism of T(3) in central neurons.
Mutations in MCT8 lead to Allan-Herndon-Dudley syndrome (AHDS), which is characterized by severe psychomotor retardation and abnormal thyroid hormone profile.
Mutations in the thyroid hormone transporter SLC16A2 (MCT8) cause the Allan-Herndon-Dudley Syndrome (AHDS), characterized by severe psychomotor retardation and peripheral thyrotoxicosis.
We tested whether mutations in MCT8 cause severe psychomotor retardation and high serum triiodothyronine (T3) concentrations in five unrelated young boys.
Mutations in the thyroid hormone (TH) transporter MCT8 have been identified as the cause for Allan-Herndon-Dudley Syndrome (AHDS), characterized by severe psychomotor retardation and altered TH serum levels.
Monocarboxylate transporter 8 is a specific thyroid hormone transporter found mutated in patients with severe psychomotor retardation and strangely abnormal thyroid hormone constellations.
The pathophysiological importance of thyroid hormone transporters has been established by the demonstration of MCT8 mutations in patients with severe psychomotor retardation and elevated serum T(3) levels.
Mutations in the MCT8 gene are associated with Allan-Herndon-Dudley Syndrome (AHDS), consisting of severe psychomotor retardation and disturbed TH parameters.
Mutations of the monocarboxylate transporter 8 (MCT8) gene determine a distinct X-linked phenotype of severe psychomotor retardation and consistently elevated T(3) levels.
Mutations in MCT8 are associated with the Allan-Herndon-Dudley syndrome (AHDS), characterized by severe psychomotor retardation and altered serum thyroid parameters.
Mutations in MCT8 are associated with elevated serum T(3) levels and severe psychomotor retardation, indicating a pivotal role for MCT8 in brain development.
Mutational analysis of the MCT8 gene revealed mutations or deletions in the MCT8 gene in unrelated male patients with severe psychomotor retardation and biochemical findings consistent with thyroid hormone resistance.
Hemizygous MCT8 mutations in males cause severe psychomotor retardation, known as the Allan-Herndon-Dudley syndrome (AHDS), and abnormal serum TH levels.
By way of whole-exome sequencing, we identified a homozygous missense mutation in VARS2 in one subject with microcephaly and epilepsy associated with isolated deficiency of the mitochondrial respiratory chain (MRC) complex I and compound heterozygous mutations in TARS2 in two siblings presenting with axial hypotonia and severe psychomotor delay associated with multiple MRC defects.
Patients with LIS1-associated classic lissencephaly typically present with severe psychomotor retardation and drug-resistant epilepsy within the first year.
Moreover, targeted sequencing of the SATB2 gene was performed in a 2-year-old girl with severe psychomotor retardation, facial hypotonia, and cleft palate who also exhibited some features of Rett syndrome.