A Rare Variant of Turner Syndrome (the X Isochromosome-X Syndrome): A Case Report

Background: Turner syndrome occurs in nearly one in every 2000-5000 female births. This syndrome is a genetic problem in the female phenotype and the most common sex chromosome anomaly. It is diagnosed based on clinical manifestations and cytogenetic examinations. The classic syndrome (i.e., monosomy X) makes up 50% of the cases while other forms contain X chromosome variants, which do not typically manifest as the classic X phenotype. Case Presentation: This study, presents a rare variant of Turner syndrome reported in a 20-year-old woman presenting with primary amenorrhea, hypothyroidism, and short stature who had hypergonadotropic hypogonadism with hypoplastic ovaries while without the clinical manifestations of the classic Turner syndrome. The karyotype was determined as X isochromosome-X syndrome [46 XXi (Xq)]. Conclusion: This rare syndrome occurs in approximately 7% of the cases of Turner syndrome. Rare variants of the syndrome should also be considered in female patients without the classic manifestations of Turner syndrome.