• The sex is determined by X and Y chromosomes. The male will have one X and one Y chromosome, while the female have 2 copies of X chromosomes. Turner syndrome is the result of a partially or completely missing sex chromosome (X chromosome).
• The exact cause for this defect is not known.
• The different genetic alterations could be:
• Monosomy: Complete absence of an X chromosome. This occurs due to error in mother's egg or father's sperm, which results in single X chromosome in every cell of the body.
• Mosaicism: Presence of a single one copy of the X chromosome or an altered copy of the chromosome in some cells. This occurs due to error in the cell division during the early stages of fetal development.
• X chromosome abnormalities: cells have one complete X chromosome and one abnormal or missing. This could occur during developmental stage or because of the error in the egg or sperm.
• Y chromosome material: some cells have a single copy of the X chromosome, while a few other cells contain some amount of Y chromosome. This condition increases the risk of developing gonadoblastoma, a type of cancer.
• The genetic alteration happens randomly and the problem in the egg or sperm could be risk factor.
• The alteration or loss of X chromosome can also happen during the fetal development.

Complications primarily result from abnormal development of the organs.

• Increased risk of diabetes and high blood pressure
• Heart and blood vessel problems
• Hearing loss
• Kidney problems
• Immune system problems
• Dental problems such as abnormal tooth development and early tooth loss
• Vision problems
• Abnormal curvature of spine
• Infertility