Kiyomi Abe, Satoshi Narumi, Ayuko S. Suwanai, Masanori Adachi, Koji Muroya, Yumi Asakura, Keisuke Nagasaki, Takayuki Abe and Tomonobu Hasegawa
Biallelic TSHR mutations cause congenital hypothyroidism (CH). Serum TSH levels of monoallelic mutation carriers range from normal to mildly elevated, and thus the size of its effect remains unclear. The objectives were to examine the association between monoallelic TSHR mutations and positivity at newborn screening (NBS) for CH, and to test whether the association was modified by another genetic factor.
Subjects and methods
We enrolled 395 patients that had a positive result in NBS and sequenced TSHR. Monoallelic TSHR mutation carriers were further sequenced for DUOX2. Molecular functions of the mutations were verified in vitro. The frequency of the mutations in the study subjects was compared with a theoretical value in the Japanese general population. Odds ratio (OR) for NBS positivity associated with the mutation was calculated. Using Bayes’ theorem, we estimated a posterior probability of NBS positivity given the mutation.
Twenty-six monoallelic TSHR mutation carriers were found. Four out of the 26 also had a monoallelic DUOX2 mutation (double heterozygotes). The frequencies of monoallelic TSHR mutation carriers (6.6%) and double heterozygotes (1.0%) were significantly higher than those in the general population (0.58% and 0.0087%, respectively). OR for NBS positivity of having a monoallelic TSHR mutation or being a double heterozygote was 12.0 or 117.9, respectively. Posterior probability of NBS positivity was 0.38% in monoallelic TSHR mutation carriers and 3.8% in double heterozygotes.
Monoallelic TSHR mutations are significantly associated with NBS positivity, and the association is further strengthened by the coexistence of monoallelic DUOX2 mutations.
Masanori Murakami, Takanobu Yoshimoto, Kazuhiko Nakabayashi, Kyoichiro Tsuchiya, Isao Minami, Ryotaro Bouchi, Hajime Izumiyama, Yasuhisa Fujii, Kosei Abe, Chiharu Tayama, Koshi Hashimoto, Takayoshi Suganami, Ken-ichiro Hata, Kazunori Kihara and Yoshihiro Ogawa
The pathophysiology of aldosterone-producing adenomas (APA) has been investigated intensively through genetic and genomic approaches. However, the role of epigenetics in APA is not fully understood. In the present study, we explored the relationship between gene expression and DNA methylation status in APA.
We conducted an integrated analysis of transcriptome and methylome data of paired APA-adjacent adrenal gland (AAG) samples from the same patient. The adrenal specimens were obtained from seven Japanese patients with APA who underwent adrenalectomy. Gene expression and genome-wide CpG methylation profiles were obtained from RNA and DNA samples that were extracted from those seven paired tissues.
Methylome analysis showed global CpG hypomethylation in APA relative to AAG. The integration of gene expression and methylation status showed that 34 genes were up-regulated with CpG hypomethylation in APA. Of these, three genes (CYP11B2, MC2R, and HPX) may be related to aldosterone production, and five genes (PRRX1, RAB38, FAP, GCNT2, and ASB4) are potentially involved in tumorigenesis.
The present study is the first methylome analysis to compare APA with AAG in the same patients. Our integrated analysis of transcriptome and methylome revealed DNA hypomethylation in APA and identified several up-regulated genes with DNA hypomethylation that may be involved in aldosterone production and tumorigenesis.
Hiroki Kobayashi, Yoshihiro Nakamura, Masanori Abe, Isao Kurihara, Hiroshi Itoh, Takamasa Ichijo, Yoshiyu Takeda, Takashi Yoneda, Takuyuki Katabami, Mika Tsuiki, Norio Wada, Yoshihiro Ogawa, Ryuichi Sakamoto, Junji Kawashima, Masakatsu Sone, Nobuya Inagaki, Takanobu Yoshimoto, Tetsuya Yamada, Ryuji Okamoto, Yuichi Matsuda, Megumi Fujita, Minemori Watanabe, Kouichi Tamura, Akiyo Tanabe, Mitsuhide Naruse and JPAS/JRAS Study Group
We investigated the clinical significance of ACTH stimulation during adrenal venous sampling (AVS) by surgical outcome of primary aldosteronism (PA).
Multicenter retrospective study by Japan PA study.
We allocated 314 patients with both basal and ACTH-stimulated AVS data who underwent adrenalectomy to three groups: basal lateralization index (LI) ≥2 with ACTH-stimulated LI ≥4 on the ipsilateral side (Unilateral (U) to U group, n = 245); basal LI <2 with ACTH-stimulated LI ≥4 (Bilateral (B) to U group, n = 15); and basal LI ≥2 with ACTH-stimulated LI <4 (U to B group, n = 54). We compared surgical outcomes among the groups using the Primary Aldosteronism Surgical Outcome (PASO) criteria.
Compared with U to U group, U to B group had poor clinical and biochemical outcomes and low rates of adrenal adenoma as pathological findings (P = 0.044, 0.006, and 0.048, respectively), although there were no significant differences between U to U and B to U groups. All patients in U to B group with clinical and biochemical benefits, however, had adrenal adenoma as pathological findings and could be well differentiated from those with poor surgical outcomes via basal LI (>8.3), but not ACTH-stimulated LI. These results were similar even when we defined each group based on a cut-off value of 4 for basal LI.
Although PA patients in U to B group had worse surgical outcomes than did those in U to U group, basal LI could discriminate among patients with better surgical outcomes in U to B group.