Cause Flashcards
What is the cause?
It is still unknown, but heritability and genetics plays a role
What have twin studies revealed?
It is a heritable trait, but it is not due to a single dominant of recessive gene - there has been no single gene shown to cause schizophrenia, several genes are involved
What does having a schizophrenia gene mean?
More susceptible to developing it - triggered by other factors
How do we know genes are involved?
Greater chance of relatives having schizophrenia if you have it
What mutation is involved?
DISC1 - disrupted in schizophrenia 1
involved in the regulation of neurogenesis, neuronal migration, post synaptic density in excitatory neurons and mitochondria function - its presence appears to increase the chance of developing it by a factor of 50
but it also increases other mental disorders, including bipolar, mood disorder and autism
How many genes have been identified?
More than 100 genes associated with the susceptibility for it
Do parents have an impact?
Paternal age provides evidence that genetic mutations impact development
What is the impact of paternal age?
Children of older fathers are more likely to develop schizohprenia
Why does paternal age impact?
More chances of getting a mutation - mutations in the spermatocytes (cells that produce sperm)
following puberty, these divide every 16 days, which means they have divided 540 times by 35
When are chromosomal abnormalities more likely?
As you get older
What are spermatocytes?
The cells that produce sperm
Why does maternal age not impact?
Women oocytes divide 23 times before birth and only one after that
Percent developing schizophrenia
General pop - 1% husband/wife - 2% cousin 2% children 13% siblings 9% DZ twins 17% parents 6% MZ twins 48% children of two schizophrenia parents 46% genetic component but not the whole story
What do MZ twins share?
They are genetically identical, and share the same intrauterine environment - but the prenatal environment isn’t always identical
How is it possible that the parental environment of MZ twins is not always identical?
There are two types of twins:
Monochorionic
Dichorionic
