The mass media report percentages of heritability. for various conditions. For instance autism is 90% heritable, height 80%, BMI 60%, musical aptitude 50%, depression 40%, breast cancer 30%. But these percentages are of no use to you, because they only apply to the population investigated, not in general. And they vary immensely between populations. Telling someone that their trait or illness has a specific heritability percentage is wrong.
Genetic variants and mutations can increase the susceptibility to psychiatric disorders. But the DSM does not really apply to the real world of genetically determined presentations. Hospital departments for DSM categories are outdated. Clusters of families would make better units for research into and care for severe mental disorders.
I can still remember the commotion which arose in 1990 when Dutch neuroscientist Dick Swaab published an article saying that homosexual men had an area in their hypothalamus which was twice the size of the same area in heterosexual men. Many found the idea – that homosexuality might have a biological basis – quite alarming! At the time I worked … Read More
The probability of having autism is greater for an individual if it runs in their family. This suggests hereditary factors. But what do you actually inherit? What you inherit is a predisposition for a specific development of your brain. This, together with what you experience while growing up, can lead to the development of a mild to severe form of autism.
Disease can be seen as the antechamber of death.
Are there reliable tests for predicting disease? The short answer is: not for Alzheimer’s or other common diseases. Tests do exist for some specific diseases, most with known familial predispositions, such as Huntington’s disease, cystic fibrosis, Duchenne’s dystrophy and many more.