Proband

The first affected individual in a family with a genetic disorder who is manifesting the disease and is diagnosed so.

Between the ancestors of the proband, there are other subjects with the manifest disease, but they might be unknown due to the lack of information regarding those individuals or the disease at the time they lived. Other ancestors might be undiagnosed due to the incomplete penetration or variable expression .

The diagnostic of the proband raise the level of suspicion for the proband's relatives and some of them may be diagnosed with the same disease. Conventionally, when drawing a pedigree chart, instead of the first diagnosed person, the proband may be chosed between the manifestly ill ancestors (parents, grandparents) from the first generation where the disease is found.