45,X/46,XY mosaicism

45,X/46,XY mosaicism is a rare chromosomal disorder where individuals have both XY and X chromosomes in different cells. This condition is also known as mixed gonadal dysgenesis or ovotesticular disorder of sex development.

Overview

45,X/46,XY mosaicism is a form of gonadal dysgenesis in which individuals have both testicular and ovarian tissue. This condition is characterized by the presence of one normal X chromosome and one Y chromosome in some cells, and a single X chromosome in others. The condition is associated with a wide range of phenotypic presentations, from typical males to ambiguous forms and typical females.

Causes

The cause of 45,X/46,XY mosaicism is not fully understood. It is believed to occur as a random event during the formation of reproductive cells (gametogenesis) or during early embryonic development. The condition is not typically inherited.

Symptoms

The symptoms of 45,X/46,XY mosaicism can vary greatly. Some individuals may have typical male or female physical characteristics, while others may have features of both sexes. This can include ambiguous genitalia, infertility, and short stature. Some individuals may also have health problems typically associated with Turner syndrome, such as heart defects and kidney abnormalities.

Diagnosis

Diagnosis of 45,X/46,XY mosaicism is typically made through genetic testing, including karyotyping and fluorescence in situ hybridization (FISH). These tests can identify the presence of different types of chromosomes in different cells.

Treatment

Treatment for 45,X/46,XY mosaicism is individualized and depends on the specific symptoms and needs of the individual. This can include hormone therapy, surgery to correct physical abnormalities, and psychological support.

See also

• Chromosome abnormality
• Intersex
• Sex chromosome disorders
• Turner syndrome