Swyer s Syndrome: Discordance between Genetic and Biological Sex - Case report

Case Report

Austin J Endocrinol Diabetes. 2023; 10(1): 1097.

Swyer’s Syndrome: Discordance between Genetic and Biological Sex - Case report

Aldao G, Mintegui G* and Agüero P

Clinic of Endocrinology and Metabolism, School of Medicine, Hospital of Clisnics, Manuel Quintela, University Republic (UdelaR)

*Corresponding author: Mintegui G Gabriela Mintegui, Clinic of Endocrinology and Metabolism, School of Medicine, Hospital of Clinics, Manuel Quintela, University Republic (UdelaR), Emilio Frugoni 1199, apartment. 601, Montevideo, Uruguay

Received: January 02, 2023; Accepted: February 10, 2023; Published: February 17, 2023


Swyer’s syndrome is a rare condition in which a disorder of the sex chromosomes produces a defective gonadogenesis with total absence of functional gonadal tissue, resulting in pure gonadal dysgenesis and discordance between genetic and biological sex. The gonads appear as rudimentary bands and the risk of developing gonadal tumors is significant. The etiology is not clear: one of the possible causes is the absence or mutations of the SRY gene located on the Y chromosome. This gene is considered to be the most important, although it is known that there are other genes involved in the cascade of sexual differentiation.

This article reports the case of a 17-year-old female phenotype patient who was studied for primary amenorrhea and presented laboratory findings compatible with hypergonadotropic hypogonadism, 46XY karyotype, who was diagnosed with Swyer Syndrome.

Keywords: Gonadal dysgenesis; Primary amenorrhea; SRY gene; Swyer’s syndrome


Gonadal dysgenesis encompasses a group of disorders of the sexual development with there is incomplete or defective formation of the ovaries or testicles due to structural or numerical abnormalities of the sex chromosomes or to mutations in the genes involved in sexual development [1,2]. Gonadal dysgenesis can be complete or partial.

Complete XY gonadal dysgenesis (complete failure of testicular development) occurs in phenotypically female individuals with the absence of secondary sexual characters, usually, due to a mutation of the SRY gene.

At birth, these individuals present a normal female phenotype but nor develop secondary sexual character in puberty. The present amenorrhea and an increased risk of gonadal tumor [3].

Clinical Case

Female patient, 17 years old, with no outstanding personal or family history, with primary amenorrhea. She presented pubarche at 15 years of age and the larche at 16 years of age. She has never received oral contraceptives and denies the use of estrogen cream. The patient doesn’t have hirsutism acne or galactorrhea. She had no elements of hypercortisolism, headache, or visual disturbances. She didn’t present symptoms of thyroid dysfunction, eating disorders or stress. Physical examination highlights: weight 51,8 kg, height 161.5 cm, Body Mass Index (BMI) 20 kg/m², female phenotype without dysmorphia and sexual infantilism, Tanner Stage II breasts, Tanner stage III pubic hair, and female external genitalia. Presented a soft abdomen, depressible, painless with no palpable tumors. Diagnostic tests from the hormonal profile, the following stand out: very decreased estradiol levels, low testosterone levels, FSH and LH increased levels and normal prolactin and TSH levels (Table 1). Therefore, the patients were diagnosed with hypergonadotropic hypogonadism. The evaluation was completed with a karyotype and SRY gene and a karyotype in peripheral blood lymphocytes that reports 46XY. No presence of SRY gene was detected by FISH. There was discrepancy between chromosomal sex and biological sex. Gynecological ultrasound did not show uterus or ovaries. Magnetic resonance imaging of the abdomen and pelvis reported the absence of uterus and ovaries and a hypoplastic vagina. Other structures were reported as normal.

Citation: Aldao G, Mintegui G and Agüero P. Swyer’s Syndrome: Discordance between Genetic and Biological Sex - Case report. Austin J Endocrinol Diabetes. 2023; 10(1): 1097.