TURNER SYNDROME: Indications & Diagnosis

Turner syndrome is a genetic disorder estimated to be found in 1 in 2500 new-born females worldwide. It is also commonly found in miscarriages. Approximatley 95% of Monosomy X conception are lost as miscarriges. Only a very small percentage survive to term or livebirth.

Turner syndrome (TS) is a chromosomal disorder involving monosomy (partial or complete) of X chromosome. The syndrome is named after Dr. Henry Turner who first observed the physical features of the affected patients. The physical manifestation of the syndrome like many genetic disorders varies from one affected person to another.

• Short stature
• Gonadal dysgenesis or premature ovarian failure
• Improper development of secondary sexual characteristics
• Learning disability
• Short or webbed neck, low-set ears, narrow finger/toenails turned upward, low hairline behind the head
• Lymphedema leading to swollen, puffy hands and feet due to accumulation of fluid (edema) in the affected parts of the body
• Congenital heart problems
• Pigmentation (coloured spots) in skin

The affected individuals with Turner syndrome has all or a portion of one of the X chromosomes missing. Another cause of Turner syndrome though rarer is Ring Chromosome or Ischromosome X. In a Ring chromosome, the ends of a chromosome break off and arms join together to form a ring, whereas in Isochromosomes, one arm of a chromosome is missing and is replaced by an identical version of the other arm. The loss of SHOX gene on X chromosome is thought to be responsible for the short strature in Turner syndrome.

Turner syndrome can be diagnosed at any stage of life. It can also be diagnosed before birth if a chromosome analysis is done during prenatal testing. Karyotyping or Chromosomal Analysis test is the most appropriate test for diagnosis of the Turner syndrome.

Genetic testing for this disorder is available in India in specialized genetic labs which do cytogenetic studies such as Karyotyping or Fluorescent In Situ Hybridization (FISH) studies.

Like most genetic disorders, there is no permanent cure for Turner syndrome, but therapies have been developed that can improve physical development. With proper medical care and support females with Turner syndrome should be able to lead full, productive lives.

Growth hormones are used in normalize the growth (height). Estrongen / progesterone therepies are used to promote puberty and development of secondary sexual characteristics.

Individuals with Turner syndrome and Y chromosome material (Y chromosome mosaicism) may be at an increased risk of developing a gonadal tumour and therefore recommended for surgical removal of non-functioning ovaries.

Unlike some other genetic disorders, Turner syndrome is not very debilitating as it does not cause mental retardation or any other major physical disability. Persons affected with turner syndrome lead a normal life. The life expectancy may be slightly shorter in some cases because of heart diseases. Affected persons may require medical help and psychological counselling and other therapies.