Unusual Combination of MEN-1 and the Contiguous Gene Deletion Syndrome of CAH and Ehlers-Danlos Syndrome (CAH-X)

Abstract

The contiguous gene deletion syndrome of congenital adrenal hyperplasia and Ehlers-Danlos syndrome, named CAH-X, is a rare entity that occurs because of a deletion of a chromosomal area containing 2 neighboring genes, TNXB and CYP21A. Here, we describe a patient from a consanguineous family in which coincidentally MEN-1 syndrome is associated with CAH-X, causing particular challenges explaining the phenotypic features of the patient. A 33-year-old man with salt-wasting congenital adrenal hyperplasia and classic-like Ehlers-Danlos syndrome presented with an adrenal crisis with a history of recurrent hypoglycemia, abdominal pain, and vomiting. He was found to have primary hyperparathyroidism, hyperprolactinemia, and pancreatic neuroendocrine tumors, as well as primary hypogonadism, large adrenal myelolipomas, and low bone mineral density. A bladder diverticulum was incidentally found. Genetic analysis revealed a heterozygous previously well-described MEN1 mutation (c.784-9G > A), a homozygous complete deletion of CYP21A2 (c.1-?_1488+? del), as well as a large deletion of the neighboring TNXB gene (c.11381-?_11524+?). The deletion includes the complete CYP21A2 gene and exons 35 through 44 of the TNXB gene. CGH array found 12% homozygosity over the whole genome. This rare case illustrates a complex clinical scenario with some initial diagnostic challenges.

Keywords: Ehlers-Danlos syndrome; adrenal myelolipoma; congenital adrenal hyperplasia; contiguous gene deletion syndrome; multiple endocrine neoplasia type 1; neuroendocrine tumor.