Down Syndrome Coding under ICD-10-CM
Down syndrome is a genetic condition in which a person is born with an extra copy of chromosome 21 (normally, individuals have 23 pairs of chromosomes in each cell); thus, the name ?trisomy 21.?
- This condition, nondisjunction, is an error in cell division that occurs at conception. This is the most common chromosomal abnormality.
- Individuals with Down syndrome may have delayed mental and social development, congenital heart defects, dementia, vision problems, gastrointestinal problems, hearing problems, sleep disturbance, and hypothyroidism.
- The number and severity of the conditions will vary from patient to patient.
There are three, specific varieties of Down syndrome:
- Nonmosaic Trisomy 2:
- Results in an extra chromosome in every cell of the body.
- This is the most common form of Down syndrome, occurring in most patients with the condition (more than 90 percent of the time). This is also called as meiotic nondisjunction.
- Mosaic Trisomy 21:
- Results in an extra chromosome in some cells, while others cells are normal. Also termed as mitotic nondisjunction.
- Translocation Trisomy 21:
- This means that part of chromosome 21 is attached (translocated) onto another chromosome, either before or after conception.
- This results in the usual two pairs of chromosome 21, but there is also additional material from chromosome 21 attached to the translocated chromosome. This is the only type of Down syndrome that can be inherited.
How to document and select code:
A Good clinical documentation should indicate the type of Down syndrome whether it is:
- Nonmosaic
- Mosaic or
- Translocation
- Any associated physical conditions and
- The degree of intellectual disabilities.
The ICD-10-CM Codes for the above terms are as follows:
- 0 Trisomy 21, nonmosaicism (meiotic nondisjunction)
- 1 Trisomy 21, mosaicism (mitotic nondisjunction)
- 2 Trisomy 21, translocation
- 9 Down syndrome, unspecified
An instructional note under category Q90 instructs one to use an additional code(s) to identify any associated physical condition and the degree of intellectual disabilities (F70-F79).