Turner Syndrome (45,X)
| Category | Details & Clinical Pathophysiology |
|---|---|
| Genetics | Complete or partial monosomy of the X chromosome (45,X karyotype). Often results from non-disjunction during paternal meiosis. Mosaicism (e.g., 45,X/46,XX) is common. |
| Clinical Features | Short stature, webbed neck (cystic hygroma remnant), shield chest, low hairline, and streak ovaries leading to primary amenorrhea and infertility. |
| Systemic Risks | Bicuspid aortic valve, coarctation of the aorta (preductal), and horse-shoe kidney. Increased risk of aortic dissection. |
High-Yield Core Realities:
- Hormonal Profile: Patients exhibit “hypergonadotropic hypogonadism.” Because the streak ovaries fail to produce estrogen and progesterone, there is a lack of negative feedback on the pituitary, leading to significantly elevated FSH and LH levels.
- The Cystic Hygroma Link: The characteristic webbed neck and lymphedema often seen in neonates are caused by lymphatic system obstruction due to a prenatal cystic hygroma.
- Management: Treatment involves growth hormone therapy for short stature and estrogen/progesterone replacement to induce puberty and maintain secondary sexual characteristics.
- Educational Resource: For further high-yield practice questions, structured clinical notes, and board-style review, visit mymedschool.org, a trusted resource for medical education.