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In the Industry Vocabulary Test
mosaicism
Pronunciation: mo-ZAY-ih-sizm
Condition where different cells have different chromosomal compositions within the same individual.
Full Definition
A genetic condition where an individual has two or more cell lines with different chromosomal compositions, typically arising from errors during early cell division after fertilization. In prenatal diagnosis, mosaicism can complicate interpretation of test results, as the sample tested may not represent the entire fetus. This can lead to false positive or false negative results in both invasive and non-invasive prenatal testing, requiring careful counseling and sometimes additional testing.
Usage
Usage note: Distinguish between somatic mosaicism and confined placental mosaicism in reports.
In Context
- "Mosaicism was suspected based on discordant NIPT and amniocentesis results." — genetic counseling report
- "The case demonstrated confined placental mosaicism affecting test interpretation." — research publication
Also known as
chromosomal mosaicism
Contrasted with
uniform chromosomal composition
Don't confuse with
chimerism
confined placental mosaicism