People who have a relative with schizophrenia have a greater risk of developing the disorder than the general population. For example, if you have an identical twin with schizophrenia, your chance of having schizophrenia is 50% in contrast to the 1% chance for the public at large. Adoption studies have shown that biological relatives have an increased risk for schizophrenia whereas adoptive relatives have no increased risk. Such studies clearly point to the contribution of a genetic component in the development of schizophrenia. Nongenetic factors can also influence the development of schizophrenia, as evidenced by the fact that, even in people with identical genes (i.e., monozygotic twins), only in about 50% of the cases are both twins ill.
There is no “gene” for schizophrenia. It’s not like having blue eyes. Having a family member with it does increase your chances slightly, but not enough that I’d worry. And with a relative as distant as an uncle, I’d be even less worried. Your risk of getting it is probably about the universal average – 1%. Schizophrenia, like all mental illness, is a complicated mixture of environment and family history.
Unfortunately yes it is believed to be hereditary: Estimates of the heritability of schizophrenia tend to vary owing to the difficulty of separating the effects of genetics and the environment although twin studies have suggested a high level of heritability.[50] It has been suggested that schizophrenia is a condition of complex inheritance, with several genes possibly interacting to generate risk for schizophrenia or the separate components that can co-occur leading to a diagnosis.[51] These genes appear to be non-specific, in that they may raise the risk of developing other psychiatric disorders such as bipolar disorder.[52] However, recent metaanalyses of linkage studies have produced conflicting findings.[53] Larger-scale, thus more sensitive genome-wide association studies are being conducted.[54] Schizophrenia has also been associated with rare deletions or duplications of tiny DNA sequences (known as copy number variants) disproportionately occurring within genes involved in neu