hereditary
Meaning of hereditary: Present from the first cell onward, even when nothing shows for decades, and never the same claim as present at birth.
Definition of hereditary
Hereditary describes a trait or condition passed from parent to child through genes carried in the egg and sperm. Because the information arrives at conception, it sits in every cell of the body from the start, whether or not anything becomes apparent for years afterward. The word says how something was acquired, not when it shows itself.
How does it differ from congenital and acquired?
| Word | What it claims | Example of the difference |
|---|---|---|
| Hereditary | Passed down through genes from a parent | A condition that only appears in middle life is still hereditary |
| Congenital | Present at birth, from any cause | Damage from an infection during pregnancy is congenital but not inherited |
| Acquired | Developed later from outside influences | Lung disease from smoking is acquired |
The categories overlap rather than exclude one another, which is where confusion starts. A condition can be hereditary and congenital at once, hereditary but silent until adulthood, or congenital with no genetic basis at all. Saying a condition runs in a family is weaker still, since relatives share meals, habits and surroundings as well as genes, and a pattern across a family can reflect either.
Does hereditary mean it is certain to happen?
No. Some faults reliably produce their effect, but many produce only a raised chance, and the gap between the two is wide. A genetic predisposition shifts the odds, and whether anything develops can depend on other genes, on chance events in individual cells, and on exposures across a lifetime. Two relatives carrying the same change may have entirely different outcomes. Age matters too, since risk that is described as lifetime risk accumulates gradually rather than arriving all at once.
What is genetic but not hereditary?
A great deal. A change can appear for the first time in an egg or sperm cell, or very early in development, so a child carries it in every cell while neither parent has it anywhere. That change is genetic, and it can be passed to the next generation, yet it was not inherited from the one before. Separately, the mutations a tumor accumulates arise in body cells during life and stay there. They drive the cancer and can be tested for in tissue samples, but they are not present in eggs or sperm and cannot be handed on. This is the practical division behind a hereditary mutation, which is carried in every cell and can be passed down, and an acquired one, which is confined to the tissue where it arose.
Also known as
Used in a sentence
Genetic counseling was offered given the patient's hereditary risk of the condition.
Good to know
A hereditary condition is not the same as a congenital one, since a congenital condition is simply present at birth and may or may not stem from an inherited genetic cause.
Word origin
Where “hereditary” comes from
From Latin hereditarius, meaning relating to an inheritance, from heres, meaning heir.