Endocrine Abstracts

Introduction: Abnormalities of the Internal Carotid Artery (ICA) are rare and agenesis has an estimated incidence of 0.01% in the general population. We here report a probable association with congenital hypopituitarism.

Case report: A baby girl presented with respiratory distress after the birth and 1 month later, because of prolonged jaundice, was found to have low FT3, FT4, and TSH (FT3 was <2.3 pmol/l FT4 was <3.5 pmol/l, TSH which was <0.1 microUI/l). She also had an undetectable Cortisol (<9 nmol/l) and IGF1 (<3,3 mmol/l. MRI imaging demonstrated an ectopic posterior pituitary gland and the anterior pituitary gland appeared very small/hypoplastic. It also showed absence of the right ICA with an anastomotic vessel arising from the cavernous segment of the left ICA, crossing the midline, reconstituting the terminal right ICA and forming the right Middle Carotid Artery further on. Genetic testing of the patient using a targeted gene approach revealed likely pathogenic variants in HESX1 and OTX1 genes which encode proteins with structural relevance to the intracranial abnormalities described. The clinical significance of these variants and their potentially additive effect contributing to disease phenotype will be discussed.

Conclusions: The case report we described is about a 5 months old patient with congenital hypopituitarism secondary to a hypoplasia of the pituitary gland, an ectopic posterior pituitary gland and the agenesis of the ICA. So far this is the 14° case with the association between congenital hypopituitarism and abnormalities of the ICA and the 4° one before the first year of age. Considering that a reduction of the blood supply is very unlikely to be the cause of the hypopituitarism, the hypothesis of a new, unknown, genetic mutation that could have caused both the pituitary hypoplasia and the agenesis of the ICA seems to be more likely.