gonosomal mosaicism

Full Definition

Gonosomal mosaicism refers to the presence of two or more cell lines with different sex chromosome compositions within the same individual. This type of mosaicism specifically affects the X and Y chromosomes and can result in various clinical presentations, including Turner syndrome variants (such as 45,X/46,XX or 45,X/46,XY), Klinefelter syndrome variants, and other sex chromosome disorders. The phenotypic expression of gonosomal mosaicism depends on the proportion of each cell line, the tissues affected, and the specific chromosomes involved.

Usage

Usage note: Preferred term over 'sex chromosome mosaicism' in formal medical writing.

In Context

• "Karyotype analysis revealed gonosomal mosaicism with a 45,X/46,XY pattern in the patient with ambiguous genitalia." — Cytogenetic report
• "The mild Turner syndrome phenotype was explained by gonosomal mosaicism rather than classic monosomy X." — Clinical genetics consultation