Question

Which type of numerical abnormality is represented by a formula of 2n + 2?

Options

• Nullisomy

• Trisomy

• Tetrasomy

• Monosomy

Answer 1

Tetrasomy (2n + 2) represents the gain of two homologous chromosomes, resulting in four copies of a chromosome pair instead of two. This condition is rare, with a total of 48 chromosomes in humans. Some viable sex-chromosome tetrasomies have been documented, but autosomal tetrasomies are typically lethal.