An Unusual Cause of Primary Amenorrhea

An 18-year-old Vietnamese female with primary amenorrhea and normal pubertal development was referred to an endocrine clinic. Despite having a normal female phenotype and normal laboratory findings, a pelvic ultrasound at age 17 revealed the absence of a uterus, and oral contraceptives failed to induce withdrawal bleeding. Her family history showed no reported infertility, with her siblings experiencing menarche at typical ages. The patient declined karyotype testing, which left müllerian agenesis, 5-alpha-reductase deficiency, and complete androgen insensitivity syndrome as differential diagnoses. However, based on her clinical presentation, the most likely diagnosis was müllerian agenesis (Mayer-Rokitansky-Kuster-Hauser syndrome), a condition with an incidence of 1/4,500-5,000 females caused by embryologic underdevelopment of the müllerian duct. Psychosocial and genetic counseling, as well as discussions on options for pregnancy, are important for patients with this syndrome, who may also exhibit certain personality traits such as higher neuroticism, depression, and decreased coping styles.