Schizophrenia (was: Good at Math(s)

[bess_va at lycos.com]

Here's some additional information concerning one "cause" of 
schizophrenia - the father's age at conception.  So, at least on that 
front, Harry is at no greater risk than the general population:
 
http://www.guardian.co.uk/Archive/Article/0,4273,4170048,00.html
Schizophrenia linked to father's age 
Tim Radford, science editor
Guardian 
Friday April 13, 2001
Men over 50 are three times more likely to father children with 
schizophrenia, according to New York scientists. And men between 45 
and 50 are twice as likely as males under 25 to have children with 
the mental illness. 
"A man has a biological clock, too," said Dolores Malaspina, of 
Columbia University college of physicians and surgeons. "Men should 
be aware of the risks when they do their family planning." 
She and colleagues worked with the New York University school of 
medicine and the Israeli ministry of health to review the records of 
almost 88,000 people born in Jerusalem between 1964 and 1976. This is 
the first link between paternal age and mental illness. There is 
growing evidence that older men are more likely to have children with 
gene-influenced illnesses. 
Paternal age has been tied to an increasing likelihood of prostate 
cancer, cancer of the nervous system, neurofibromatosis, the most 
common type of dwarfism, malformation of the skull, hands and feet, 
and Marfan syndrome, which involves defects of the eyes, bones, heart 
and blood vessels. 
Most of these are rare conditions. Schizophrenia affects one in 100 
and the paternal age connection would only become visible in a very 
large survey. 
The hypothesis is that with the years sperm cells are more likely to 
accumulate mutations which could be passed on to offspring. But 
schizophrenia remains a puzzle. It seems to be more prevalent in some 
groups, and researchers have claimed several times to have identified 
schizophrenia genes. 
However, there could also be environmental factors. The New York 
study cannot identify which genes or what environmental factors might 
be at work. 
But the illness is remarkably persistent in human populations, even 
though schizophrenics are less likely to marry and have children. The 
New York scientists believe the paternal age factor might explain why 
the proportion of schizophrenics remains roughly the same in each 
generation. 
The researchers reported in the latest Archives of General Psychiatry 
that more than 26% of cases could be attributed to the father's age. 
Susan Harlap, of New York University, a co-author of the report, 
said: "Our study suggests that a man's progeny are going to be 
healthiest if he has his children during his early 20s. But we know 
that many men aren't ready for marriage and parenthood at that age." 
She added: "I would guess that our study is just the tip of the 
iceberg. It would seem that the father's sperm is going to turn out 
to be just as important as the mother's egg."