Adrenal hypoplasia congenita (AHC) is a rare X-linked recessive disease caused by mutations in the nuclear receptor subfamily 0, group B, member 1 (NR0B1) gene, which is also referred to as dosage-sensitive sex-reversal, adrenal hypoplasia congenita, in the critical region of the X chromosome, gene 1 (DAX1). This gene is expressed in the hypothalamus, anterior pituitary and steroidogenic tissues, including the gonads and adrenal cortex. Adult-onset forms of X-linked AHC are a significant cause of concern. In the present study, the case of a 21-year-old male who exhibited adrenal insufficiency and hypogonadotropic hypogonadism was described. The patient initially presented with nausea, vomiting, fatigue and dizziness. The laboratory results demonstrated that the patient had hyponatremia, a low basal cortisol concentration and increased adrenocorticotropic hormone levels. Molecular genetic examination revealed a novel frameshift mutation (c.1005delC, p.V336Cfs*36). Following steroid supplementation, the patient's vomiting, fatigue and dizziness rapidly improved. To the best of our knowledge, the present study was the first case report of adult-onset X-linked AHC with this novel frameshift mutation. Furthermore, the present study highlighted differences in the clinical presentation of adult-onset forms of X-linked AHC. This may therefore alert medical professionals to the need to perform genetic analysis for DAX1 mutations in adolescents and adults with primary adrenal insufficiency and hypogonadotropic hypogonadism.