Hypoparathyroidism associated with aneurysm of the left subclavian artery (Kommerell's diverticulum) in an adult patient with a chromosome 22q11.2 deletion.

Hypoparathyroidism may either be acquired or of congenital origin. From the latter group, which represents a minority of cases, agenesis or hypoplasia of the parathyroid glands resulting in symptomatic hypocalcemia in the newborn or infant frequently is caused by a microdeletion of chromosome 22q11.2. We describe a man in whom hypoparathyroidism was first diagnosed at the age of 59 years. The endocrine disorder was found to be associated with this chromosome imbalance and also with an aneurysm of the left subclavian artery (Kommerell's diverticulum) compressing the esophagus and trachea. Given the potential implication for genetic counseling, a 22q11.2 deletion should be considered in the differential diagnosis of adult patients with hypoparathyroidism of unknown origin and should be searched for by appropriate molecular cytogenetic technique.