Turner Syndrome: Phenotypic Variability of Chromosomal Polymorphism

Abstract

Turner syndrome was firstly described by N. Shereshevskyi in 1925, and then by H. Turner in 1938. In 1959, Ch. Ford found that in patients with this syndrome one X chromosome is absent. The cause of this is that in the process of fertilization, one of two X chromosomes of maternal egg or paternal sperm is lost. Recent studies have suggested that two-thirds of patients with Turner syndrome do not have one X chromosome. Patients are almost exclusively women. Their karyotype is 45, X. Among newborn girls, Turner syndrome occurs with a frequency of 1 : 3,000, and among girls suffering from mental retardation — 1 : 1,500. The decisive arguments in the diagnosis of Turner syndrome are typical clinical features; data of study of sex chromatin and karyotype; possible prenatal diagnosis of fetal pathology. Patients with Turner syndrome require hormone therapy (by growth hormone, sex hormones), correction of congenital malformations and aesthetic defects. This article summarizes data of features of phenotypic manifestations of Turner syndrome, depending on the variant of chromosomal abnormalities.

Keywords

• Turner syndrome
• girls
• X chromosome.