Autoimmune thyroid disease and pituitary adenoma in a female patient with 18p deletion syndrome: a case report and review of the literature.

Background: 18p deletion (18p-) syndrome is a rare chromosomal abnormality with a wide range of phenotypes. Its main clinical features are short stature, intellectual disability, and facial dysmorphism, which are rarely accompanied by autoimmune thyroid disease (ATD) or pituitary abnormalities. Herein, we report the first Chinese patient with a de novo 18p deletion who presented with ATD and non-functioning pituitary adenoma.

Case presentation: A 24-year-old female patient presented with severe ptosis, intellectual disability, hypothyroidism associated with Hashimoto's thyroiditis, and a non-functional pituitary adenoma. Deletion of the short arm of chromosome 18 was detected in a G-banded karyotyping (46, XX, del [18] [p11.1]). Chromosomal microarray analysis revealed a 14.9 Mb deletion in chromosome 18p11.32p11.21, defined as arr[GRCh38]18p11.32p11.21(136227-15079295)x1. The literature review indicated that patients with 18p- syndrome and ATD were predominantly female with early disease onset (mean age: 15 years).

Conclusions: 18p- syndrome is associated with ATD and pituitary abnormalities. Therefore, endocrine system evaluation and genetic analysis of the 18p breakpoint region are valuable for predicting patient prognosis.