Turner Syndrome manifests itself differently in each patient. This post will examine the different variations of Turner Syndrome and what that means for girls and women with the condition.
Many people do not realize that there are two variations of Turner Syndrome, commonly called classic and mosaic. Patients with each type can show similar physical characteristics, like webbed necks, swollen feet and hands, stunted growth, kidney problems, heart problems, infertility, delayed/absent onset of menses (periods), and high palates.
There are also some other common characteristics, such as exhibiting traits of learning disabilities (particularly Non-Verbal Learning Disability, or NVLD), social challenges, and other cognitive issues. However, the prevalence of these issues often varies depending on the type of Turner Syndrome a woman or girl has. It is more common to have classic Turner Syndrome than mosaic. Why? The answer has to do with chromosomal differences.
The Science of DNA
First, a quick science recap: During human reproduction, 23 sex cells are created. Inside each cell, there are two chromosomes that hold the genetic instructions for running the cell. These instructions are known as DNA. Each parent typically gives one chromosome. Usually, a person would have 46 chromosomes in total, with all of their cells either having all XX chromosome pairs (biologically female) or XY chromosome pairs (biologically male). With Turner Syndrome, the female chromosome pairs do not fit this pattern.
Mosaic vs. Classic
- Classic Turner Syndrome (or non-mosaic Turner Syndrome) – all cells lack one X chromosome
- Mosaic Turner Syndrome – cells vary in chromosomal content, with some cells having both X chromosomes and others having an incomplete amount of X chromosomes (either with an absent X chromosome; with one full X chromosome and one incomplete X chromosome; or, in few cases, one full X chromosome and and one incomplete Y chromosome)
Impacts of the Turner Syndrome Variations
The type of Turner Syndrome matters, because it can alter the impact of physiological characteristics on the individual. While the effects vary for every girl and woman diagnosed with Turner Syndrome, those who have classic Turner Syndrome generally face more health obstacles than those with mosaic Turner Syndrome. This is because, with classic Turner Syndrome, more of the cells are chromosomally incomplete than with the mosaic type. However, there are some exceptions to this general finding.
If you or your child have Turner Syndrome, you should consult your health care team to learn whether you are a patient with classic or mosaic type of the condition. As always, every person’s situation is unique, and you should work with trusted health care providers to ensure you receive the care you need.