An infant is born at 40 weeks and 5 days’ gestation to a 26-year-old gravida 1, para 1 woman without a significant medical history and a benign prenatal course. Based on noninvasive prenatal testing at 15 weeks’ gestation with 46,XY chromosomes (Fig 1), the parents were expecting a male infant. At the time of delivery, the infant was vigorous with external genitalia consistent with a typical female appearance. Physical examination findings were notable for palpable masses bilaterally in the labia. Pelvic ultrasonography was performed (Video). The infant’s electrolytes were normal on the second day after birth and additional laboratory testing was performed over the next several weeks (Table 1).
Based on the aforementioned information, the most likely diagnosis for this infant is:
5α-reductase 2 deficiency
Complete androgen insensitivity
Complete XY gonadal dysgenesis (Swyer syndrome)
Leydig cell hypoplasia
The Video clip of this...