What is the correct nomenclature for a hematologic disorder with trisomy 21 in 6 cells and 14 normal cells?

The correct nomenclature for describing a hematologic disorder with a specific cytogenetic anomaly must accurately reflect the total number of chromosomes, the sex chromosomes involved, and the nature of the abnormality, including the proportion of affected and normal cells.

In this case, there is a total of 47 chromosomes in the cells with trisomy 21, with 21 being the extra chromosome. The notation should indicate the presence of the extra chromosome, which is portrayed as “+21”. Since the disorder is specified, we also include the number of affected cells and the number of normal cells.

The chosen answer identifies a total of 47 chromosomes in affected cells, detailing the specific condition of those cells (trisomy 21) with a proper format. It aptly indicates that in 6 of the cells, there is the additional chromosome (represented by the “?c[6]” for atypical or atypical count indicating the specific cellular makeup), while also listing 14 normal cells at the standard diploid count of 46 chromosomes.

This nomenclature balances technical correctness with clarity. The presence of both combination notations reflects the different cell populations – affected and unaffected – and provides essential clinical relevance by indicating the type of abnormality in a precise manner.