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A systematic review of genetic studies of thyroid disorders in Taiwan identified studies of gene mutations involved in the synthesis and binding of thyroid hormone, as well as mutations of proto-oncogenes and tumor suppressor genes in thyroid cancer. Studies related to gene polymorphisms in patients with autoimmune thyroid disease (AITD) and thyroid cancer were also reviewed. The most prevalent mutations in the Han-Chinese population were c.2268insT in the thyroid peroxidase (TPO) gene and c.919-2A>G in the Pendred syndrome (PDS) gene. Additional mutations have also been revealed in the genes encoding TPO (n = 5), thyroglobulin (TG; n = 6), pendrin (n = 2), and thyroxine-binding globulin (TBG; n = 2), which were novel at the time they were reported. The prevalence of various somatic mutations in differentiated thyroid cancer was similar in Taiwan and Western countries, with the RAS kinase mutation and tyrosine receptor kinase (TRK) and rearranged during transfection (RET) proto-oncogenes being detected in lower frequencies and the B-type RAF kinase (BRAF) mutation accounting for the majority of cases. Recent microRNA analysis revealed an association between miR146b and the BRAF mutation, which was associated with poor prognosis of papillary thyroid carcinoma (PTC). Susceptibility to Graves' disease (GD) was linked to the human leukocyte antigen (HLA) region. The associated alleles were different in Han-Chinese and Caucasians; HLA-DPB1*0501, the major allele in Taiwan, has a low frequency in the West. By contrast, a high frequency of HLA-DRB1*0301 was detected in Caucasians but not Han-Chinese. In addition to the HLA region, cytotoxic T lymphocyte-associated molecule-4 (CTLA4) gene polymorphisms +49G>A and +6230G>A (CT60) were positively associated with GD. The GG genotype and G allele of single nucleotide polymorphism (SNP) +49G>A were also related to relapse of Graves' hyperthyroidism after antithyroid drug withdrawal. Differences in the genetic patterns between Han-Chinese and Caucasians for some thyroid disorders suggest the importance of variable genetic influences in different populations., (Copyright © 2014. Published by Elsevier Taiwan.)

Background: Hirschsprung's disease (HSCR), or aganglionic megacolon, is a hereditable disease of the enteric nervous system. It is an embryonic developmental disorder characterized by the absence of ganglion cells in the lower enteric plexus. Gut motility is compromised in HSCR, with consequent risk of intestinal obstruction., Methods: We sequenced the RET gene and characterized the clinical manifestations in 15 unrelated Chinese patients (9 males, 6 females; age range, 2-21 years) with sporadic HSCR. Genomic DNA extraction, PCR and DNA sequence analysis were performed according to standard procedures., Results: We identified heterozygous RET gene mutations in 2 patients. The mutations included a missense mutation in exon 2 (CGC --> CAC) resulting in a substitution of arginine by histidine at codon 67 (patient 1), and a missense mutation in exon 3 (TAC --> AAC) resulting in a substitution of tyrosine by asparagine at codon 146 (patient 2). The pathological findings disclosed short-segment HSCR in patient 1 and long-segment HSCR in patient 2, respectively., Conclusion: We identified RET gene mutations in 2 of 15 patients with HSCR in Taiwan. The Y146N mutation we identified was novel.

Background: This study compares the cardiovascular autonomic function in type 2 diabetes with and without microalbuminuria, in order to identify the possible links between early nephropathy and diabetic autonomic neuropathy (DAN)., Methods: Cardiovascular reflex tests were performed to determine the cardiovascular autonomic function. Thirty cases of type 2 diabetes with microalbuminuria were studied for evidence of DAN to compare with a normoalbuminuric group of 56 diabetic patients., Results: There was an increased prevalence of autonomic dysfunction in patients with microalbuminuria (63.3% in the microalbuminuria group vs. 40.0% in the normoalbuminuric controls, p = 0.001). These patients had lower heart rate variability during single breathing tests (6.9 +/- 4.3 vs. 9.6 +/- 3.6 beats/minute, p = 0.005), during 6 consecutive breathings (5.8 +/- 3.6 vs. 8.2 +/- 3.3 beats/minute, p = 0.005), after standing up (12.2 +/- 4.6 vs. 15.0 +/- 5.2 beats/ minute, p = 0.012), and during the Valsalva maneuver (11.3 +/- 3.5 vs. 13.2 +/- 3.6 beats/minute, p = 0.022). The heart rate variability with these stresses was revealed to be less favorable in subjects with microalbuminuria. However, blood pressure (BP) changes from the sitting to standing position were not significantly different for systolic BP (11.5 +/- 10.7 vs. 10.7 +/- 7.8 mmHg, p = 0.741) and diastolic BP (5.2 +/- 4.4 vs. 5.9 +/- 4.0 mmHg, p = 0.451) between the 2 groups., Conclusion: Type 2 diabetic patients with microalbuminuria have diminished heart rate variability in response to deep breathing, change of position and the Valsalva maneuver, but they preserve BP response to postural change. Therefore, microalbuminuria seems to be associated with early DAN, but not with advanced DAN.

Although involvement of the adrenals by malignant lymphoma is common, primary adrenal lymphoma is extremely rare. Herein, we report a case of a 59-year-old woman with bilateral adrenal glands enlargement found incidentally on abdominal imaging. Despite of the huge size of the tumor, her adrenal function was intact. Ultrasound-guided biopsy disclosed a picture of malignant lymphoma, diffuse large B cell type. The patient received bilateral adrenalectomy and adjuvant chemotherapy, but succumbed 6 months later. We suggest that, although rare, primary adrenal lymphoma should be considered as a possible cause of bilateral adrenal incidentalomas.