A Case of Familial Nonautoimmune Hyperthyroidism During Pregnancy

Yuka Okazaki, MD; Naoko Arata, MD, PhD; Nagayoshi Umehara, MD, PhD; Taisuke Yamauchi, MD, PhD; Junnichi Tajiri, MD, PhD; Akira Hishinuma, MD, PhD; Takahiko Kogai, MD, PhD; Takashi Idegami, MD; Atsuko Murashima, MD, PhD; Haruhiko Sago, MD, PhD

AACE Clinical Case Reports (Mar 2020)

A Case of Familial Nonautoimmune Hyperthyroidism During Pregnancy

Yuka Okazaki, MD,
Naoko Arata, MD, PhD,
Nagayoshi Umehara, MD, PhD,
Taisuke Yamauchi, MD, PhD,
Junnichi Tajiri, MD, PhD,
Akira Hishinuma, MD, PhD,
Takahiko Kogai, MD, PhD,
Takashi Idegami, MD,
Atsuko Murashima, MD, PhD,
Haruhiko Sago, MD, PhD

Affiliations

Yuka Okazaki, MD: From the Division of Maternal Medicine, Center of Maternal-Fetal, Neonatal, and Reproductive Medicine, National Center for Child Heath and Development, Tokyo, Japan
Naoko Arata, MD, PhD: From the Division of Maternal Medicine, Center of Maternal-Fetal, Neonatal, and Reproductive Medicine, National Center for Child Heath and Development, Tokyo, Japan; Address correspondence to Dr. Naoko Arata, Division of Maternal Medicine, Center of Maternal-Fetal, Neonatal, and Reproductive Medicine, National Center for Child Heath and Development, 2-10-1 Ohkura Setagaya-ku, Tokyo, 157-0074, Japan.
Nagayoshi Umehara, MD, PhD: Division of Obstetrics, Center of Maternal-Fetal, Neonatal, and Reproductive Medicine, National Center for Child Heath and Development, Tokyo, Japan
Taisuke Yamauchi, MD, PhD: Yamauchi Clinic, Saitama, Japan
Junnichi Tajiri, MD, PhD: Tajiri Clinic, Kumamoto, Japan
Akira Hishinuma, MD, PhD: Department of Infection Control & Clinical Laboratory Medicine, Dokkyo Medical University, Tochigi, Japan
Takahiko Kogai, MD, PhD: Department of Infection Control & Clinical Laboratory Medicine, Dokkyo Medical University, Tochigi, Japan
Takashi Idegami, MD: Department of Obstetrics, Japanese Red Cross Kumamoto Hospital, Kumamoto, Japan.
Atsuko Murashima, MD, PhD: From the Division of Maternal Medicine, Center of Maternal-Fetal, Neonatal, and Reproductive Medicine, National Center for Child Heath and Development, Tokyo, Japan
Haruhiko Sago, MD, PhD: Division of Obstetrics, Center of Maternal-Fetal, Neonatal, and Reproductive Medicine, National Center for Child Heath and Development, Tokyo, Japan

Journal volume & issue: Vol. 6, no. 2
pp. e94 – e97

Abstract

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ABSTRACT: Objective: Familial nonautoimmune hyperthyroidism (FNAH) is a rare disease. To date there are few, if any, reports of pregnancies in women with FNAH. Our objective here is to present such a case. Methods: Free thyroxine (free T4), free triiodothyronine (free T3), thyroid-stimulating hormone (TSH), and antibodies related to the thyroid were measured. Fetal thyroid function indicators including thyroid volume and ossification were checked using ultrasound. Thyroid-stimulating hormone receptor (TSHR) gene analyses were performed. Results: The patient was a 30-year-old woman with no past medical history. She was introduced to our hospital in the fifth gestational week for pregnancy care because her family history revealed that her mother had nonautoimmune hyperthyroidism with a TSHR-activating germ-line mutation (Asn406Ser). The serum free T4 was 1.88 ng/dL (normal, 0.62 to 1.19 ng/dL), free T3 was 3.27 pg/mL (normal, 2.55 to 3.88 pg/mL), TSH was 0.02 μIU/mL (normal, 0.007 to 3.619 μIU/mL), and TSHR was negative which were considered to be consistent with mild primary hyperthyroidism. Serum free T4, free T3, and TSH concentrations were monitored every 4 to 6 weeks with a peak free T4 of 2.23 ng/dL noted at gestational week 9. The patient had no signs related to hyperthyroidism throughout pregnancy. The patient delivered a 3,518 g girl at 40 weeks of gestation. Genetic analysis of her TSHR gene showed heterozygous Asn406Ser mutation. The offspring did not show any signs of prenatal hyperthyroidism, and thyroid function at day 6 after delivery revealed a free T4 of 2.41 ng/dL (normal, 1.83 to 2.91 ng/dL) and a TSH of 3.55 μIU/mL (normal, 0.51 to 4.57 μIU/mL). Conclusion: Women with FNAH and mild thyrotoxicosis prior to pregnancy may have continuous hyperthyroidism with additional change due to the series of human chorionic gonadotropin secretion during pregnancy.

Published in AACE Clinical Case Reports

ISSN: 2376-0605 (Online)
Publisher: Elsevier
Country of publisher: United States
LCC subjects: Medicine: Internal medicine: Specialties of internal medicine: Diseases of the endocrine glands. Clinical endocrinology
Website: https://www.journals.elsevier.com/aace-clinical-case-reports

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