Endocrine Abstracts

JOINT1529

Introduction: Down syndrome (DS) is a genetic disorder leading to a range of physical and cognitive impairments. Endocrine abnormalities such as thyroid disorders are prevalent among patients with DS. (1).

Case presentation: We report the case of a 26-year-old female patient, previously followed for DS since childhood, referred to the endocrinology department at the age of 19 after developing clinical symptoms suggestive of hypothyroidism. Laboratory tests revealed a TSH level of 11 µU/ml, FT4 of 15 pmol/l, and positive anti-TPO antibodies. A cervical ultrasound showed a heterogeneous, hypoechoic, pseudonodular thyroid gland of normal size, with decreased vascularity on color Doppler. The patient was started on Levothyroxine. At the age of 26, the patient presented with menstrual irregularities. Laboratory tests showed a TSH level of 2.02 µU/ml and hyperprolactinemia with a prolactin level of 977 mUI/ml. A pituitary MRI revealed a 5 mm anterior pituitary microadenoma. The patient was started on Cabergoline.

Discussion and Conclusion: This case highlights the complex interplay between Down syndrome and endocrine disorders, particularly hypothyroidism and hyperprolactinemia. Individuals with Down syndrome are at increased risk for thyroid dysfunction, with autoimmune hypothyroidism being one of the most common endocrinopathies observed in this population. Additionally, the development of hyperprolactinemia in this patient is of particular interest. Hyperprolactinemia is often secondary to thyroid dysfunction, especially in cases of untreated or poorly managed hypothyroidism. Prolactinomas are observed more frequently in DS compared to general population according to some observational studies (1). The patient’s prolactin level of 977 mUI/ml and the MRI findings of a pituitary microadenoma led to the diagnosis of a prolactin-secreting adenoma. Treatment with Cabergoline resulted in both clinical and biochemical improvement of hyperprolactinemia. This case also underscores the importance of regular endocrine monitoring in individuals with Down syndrome, as they are susceptible to multiple endocrine abnormalities. Early diagnosis and treatment of these conditions can significantly improve the patient’s quality of life and prevent long-term complications, especially in the presence of premature mortality in these patients (1). (1) Rivelli A, Fitzpatrick V, Wales D, Chicoine L, Jia G, Rzhetsky A, Chicoine B. Prevalence of endocrine disorders among 6078 individuals with Down syndrome in the United States. J Patient Cent Res Rev. 2022;9:70-4. doi: 10.17294/2330-0698.1877.