Magnetic resonance imaging of XXXX in subjects with resistance to thyroid hormone.

@entity1 @entity71 @entity600 @entity1316 @entity74 @entity1779
OBJECTIVE: Resistance to thyroid hormone (RTH) is an @entity74 caused by mutations in the @entity1 thyroid receptor beta gene on chromosome 3. Individuals with RTH have an increased incidence of @entity71 ( @entity71 ). The purpose of this study was to search for @entity600 associated with RTH. METHOD: Forty-three subjects (20 affected males [AM], 23 @entity1316 [ @entity1316 ]) with resistance to thyroid hormone and 32 unaffected first degree relatives (18 unaffected males [UM], 14 unaffected females [UF]) underwent MRI brain scans with a volumetric acquisition that provided 90 contiguous 2 mm thick sagittal images. Films of six contiguous images beginning at a standard sagittal position lateral to the insula were analyzed by an investigator who was blind with respect to subject characteristics. The presence of extra or missing gyri in the parietal bank of the Sylvian fissure (multimodal association cortex) and multiple Heschl's transverse gyri (primary auditory cortex) were noted. RESULTS: There was a significantly increased frequency of anomalous Sylvian fissures in the left hemisphere in males with RTH (AM: 70%; @entity1316 : 30%; UM: 28% UF: 28%). Also, there was an increased frequency of anomalous Sylvian fissures on the left combined with multiple Heschl's gyri in either hemisphere in males with RTH (AM: 50%; @entity1316 : 9%; UM: 6%; UF: 0%). However, RTH subjects with anomalies did not have an increased frequency of @entity71 as compared with RTH subjects with no anomalies. CONCLUSIONS: Abnormal thyroid hormone action in the male fetus early during brain development may be associated with grossly observable @entity1779 of the left hemisphere. The effects of mutations in the thyroid receptor beta gene provide a model system for studying the complex interaction of genetic and nongenetic factors on brain and behavioral development.
