Hemizygosity (deletion) Clinical Dosage Map explanation.
This map presents the current state of the science for all possible phenotypes or characteristics that could potentially be associated with a single copy deletion of a portion of chromosome 18. Some of the features are associated with a specific gene and others with a specific region that includes several genes for those cases in which the specific causative gene is not yet known.
There are two important points to remember:
- The vast majority of the listed features have an extremely low probability of occurring in someone with a deletion of the identified section of the chromosome.
- Genomic data interpretation is in its infancy. These data summarize the current state of the science and are continuously revised and updated as new information is learned. There is much yet to learn.
Each feature is classified by its possible risk of causing that condition and each level of risk has a color code for easier identification. The classifications are color coded on the map as follows:
- Low penetrance. These conditions occur as a result of hemizygosity but only in fewer than 50% of people with a deletion of this gene or region. This determination is based primarily on our own previously reported genotype-phenotype correlation data. (genes indicated in orange)
- Causal. These genes or regions are associated with an abnormal condition in at least 50% of the people with hemizygosity (a deletion) of this gene or region. (genes indicated in pink)