Monosomíur

Monosomíur are a type of chromosomal disorder characterized by the presence of only a single copy of a particular chromosome, instead of the usual pair. This condition results from a failure in the process of chromosomal separation during meiosis or mitosis, leading to a missing chromosome in the affected cells. Monosomies are generally lethal when they involve autosomes, as the loss of an entire chromosome often disrupts essential gene functions, making viable cases rare and usually limited to sex chromosomes.

The most common monosomy involving sex chromosomes is Turner syndrome (monosomy X), where individuals have only one X chromosome instead of two sex chromosomes (XX or XY). Turner syndrome affects approximately 1 in 2,500 female live births and is associated with features such as short stature, ovarian insufficiency, and certain physical anomalies. Other monosomies of sex chromosomes are typically less viable and tend to result in miscarriage or severe developmental issues.

Monosomies of autosomes—chromosomes that carry genetic information vital for general body development—are generally incompatible with life. Survivors, if any, typically face severe health challenges, developmental delays, and organ malformations. The rarity of autosomal monosomies is due to the critical functions that many genes on autosomes serve.

Diagnosis of monosomy involves genetic testing, such as karyotyping or fluorescence in situ hybridization (FISH). Genetic counseling is important for affected individuals and families, as it provides information about recurrence risks and management options.

Overall, monosomies reveal the crucial role of balanced chromosome complement for normal human development and health. They serve as important subjects for understanding genetic diseases and chromosomal biology.