Three generation pedigree chart

About this three generation pedigree chart

A three-generation pedigree chart represents individuals and relationships. Circles represent females, while squares represent males. A horizontal line connecting a circle and square shows a marriage, and vertical lines dropping from that connection represent their children.

Shaded symbols are used to show individuals affected by a particular genetic condition or disease. Half-shaded symbols show carriers of a genetic disorder, meaning they carry the gene but do not show its symptoms. A diagonal line through a symbol means the person is deceased.

In a three-generation chart, the top row represents the first generation, usually the grandparents. The second generation, usually the patient's parents and their siblings, appears in the middle. The third generation, which includes the patient and their siblings, is at the end.

An arrow pointing to a circle or square represents the patient (called the "proband"). Twins are shown by gender symbols marked with a horizontal line connecting two vertical lines. A double line between partners represents consanguinity (a relationship between blood relatives). This chart helps healthcare professionals assess the risk of hereditary diseases and make informed medical decisions.