Marker chromosomes in normal individual

This code signifies the presence of extra, structurally abnormal chromosomes, known as marker chromosomes, in an individual who otherwise presents with a normal phenotype and no apparent clinical abnormalities. These markers are typically small, supernumerary chromosomes of unknown origin or composition. The individual does not exhibit any associated genetic syndromes or developmental delays.

Apply this code when genetic testing, such as karyotyping or FISH, identifies marker chromosomes in an asymptomatic individual. Documentation should explicitly state the presence of marker chromosomes and confirm the absence of any associated clinical manifestations or genetic disorders. This is often an incidental finding during prenatal screening or genetic evaluation for other reasons.

• Do not use this code if the marker chromosome is associated with a known syndrome or clinical abnormality; instead, code the specific syndrome.
• Ensure documentation clearly states "normal individual" or "asymptomatic" in conjunction with the marker chromosome finding.
• This code is for the presence of the marker chromosome itself, not for the reason the genetic testing was performed.