Endocrine Abstracts

Introduction: X-linked adrenal hypoplasia congenita (AHC) is a rare developmental disorder of the adrenal cortex. Adrenal insufficiency typically begins in infancy or in childhood. A few individuals present adrenal insufficiency in adulthood.

Case report: A 21-year-old man visited our endocrine out-patient clinic due to underdeveloped secondary sexual characteristics, which was found at physical examination for military service. Physical examination revealed small bilateral testes, sparse pubic, axillary hair, and a large arm span-to-height ratio. Besides, pigmentation in mouth, on palmar creases and joints were noted. Endocrine function evaluation showed high ACTH (>1250 pg/ml), low cortisol (5.37 μg/dl), low testosterone (0.541 ng/ml) with low FSH (4.79 mIU/ml), and low LH (2.77 mIU/ml). Peak LH level was 16.4 mIU/ml after LHRH stimulation, but response of FSH, LH, and testosterone to clomiphene was impaired. Thyroid function, HbA1c and serum electrolyte, plasma renin activity, and aldosterone levels were normal. Abdominal computed tomography scan revealed bilateral small adrenal glands. Brain MRI revealed no lesion at pituitary gland or hypothalamus. Adrenal hypoplasia congenital was suspected due to combined primary adrenal insufficiency and hypogonadotropic hypogonadism. Genetic study revealed a missense mutation (c.849G>C) in the DAX-1 gene (dosage-sensitive sex reversal adrenal hypoplasia congenita, critical region on the X chromosome gene-1), which was transmitted from his mother.

Conclusion: DAX-1 gene deletions or mutations have been reported to be responsible for AHC. We report a case of AHC with adult-onset adrenal insufficiency, hypogonadotropic hypogonadism, and a novel missense mutation in the DAX-1 gene.