Wednesday, December 31, 2008

Study: Bipolar Disorder Linked to Older Dads

Study: Bipolar Disorder Linked to Older Dads
at:2008-12-31 05:25:14 Click: 12
Schizophrenia, autism and now bipolar disorder are all linked with older fathers. Here is the Associated Press story by Lindsey Tanner that ran two days ago discussing the newest study.

CHICAGO (AP) — Children born to older fathers face a greater chance of developing bipolar disorder, according to one of the largest studies linking mental illness with advanced paternal age.

Previous research has connected schizophrenia and autism with older dads, and a Danish study published last year added bipolar disorder to the list. The new study led by researchers at Sweden's Karolinska Institute strengthens the evidence.

The leading theory is that older men's sperm may be more likely to develop mutations. Even so, the odds of a person becoming bipolar are so low that the study's authors said it shouldn't dissuade older men from becoming fathers.

Researchers analyzed Swedish national registry data from more than 80,000 people, including 13,428 with bipolar disorder who were born between 1932 and 1991.

The risks started increasing around age 40 but were strongest among those 55 and older. Children born to these dads were 37 percent more likely to develop bipolar disorder than those born to men in their 20s.

They also faced more than double the risk of developing bipolar disorder before age 20. Scientists call that early onset disease, and while they have long known that bipolar disorder tends to run in families, early onset disease has been thought to be most strongly linked with genetics.

The age of the mothers didn't appear to be much of a factor.

The study, released Monday, appears in September's Archives of General Psychiatry.

While the findings don't explain what might cause some older men to have bipolar children, it "reinforces the notion that there's a strong biological component to this," said Dr. Harold Pincus, vice chair of psychiatry at Columbia University.

Bipolar disorder causes dramatic mood swings, from deep depression to manic highs. It affects more than 5 million Americans.

Lifetime risks for it have been estimated at roughly 1 percent to 4 percent. The study results suggest that having an older father might increase that slightly. The findings aren't definitive, but even if the link proves to be real, Pincus noted that still means most people with older fathers won't ever get bipolar disorder.

Factors involving mothers, including age and health, have long been thought to be most closely linked with birth defects and other abnormalities. But the new study adds to mounting evidence that paternal factors also play an important role, said New York University researcher Susan Harlap.

Sperm are produced throughout a man's lifetime, and scientists believe that as men age there is a greater chance for mutations that could contribute to disorders in their children.

Advanced paternal age also has been linked with birth defects, and some sperm banks have age limits for donors because of that.

While important for scientists, the study results shouldn't discourage older men from fathering children, said Emma Frans, the lead author.

She said the results suggest that similar mechanisms might contribute to risks for bipolar disorder, schizophrenia and autism. Each of these disorders is thought to have many causes including biologic and outside factors.

On the Net:
National Institutes of Health bipolar information:

Les at : 2008-12-31 08:25:35
Type 1 diabetes, MS, Alzheimer's, cerebral palsy, epilepsy, breast, prostate, leukemia, and early childhood cancer are among the many other disorders that rise in incidence with increasing paternal age. Some sperm US banks refuse sperm of a man past his 35th birthday to try an avoid paternal age related genetic disease. By the age of 33-35 men are rapidly accumulating mutations in their sperm making cells.


Saturday, December 13, 2008

The Age of Fathers Can Matter to Fertility and to the Genetic health of the child

How new study about fertility risk for men over 35 woke me up to my own biological timebomb
By Nic Fleming
Last updated at 9:58 PM on 13th December 2008
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While I have always said I want children, I have rarely felt in a rush to do anything about it.
The joys of nappy changing, parents’ evenings and Center Parc holidays have yet to entice me, at the age of 37, to join the ranks of new fathers among my friends who are increasingly absent from trips to the football and nights in playing Grand Theft Auto on the Xbox.
But my state of responsibility-free bliss has been undermined by a study published in July by French researcher Dr Stephanie Belloc.
Decision time: Author Nic Fleming with his fiancee Linda Geddes

Analysing the records of 12,000 couples who attended her fertility clinic in Paris, she found that women whose husbands or boyfriends were aged 35 and above were more likely to have miscarriages than those with younger partners.
Her findings back up a study by Bristol University that found women with partners aged 35 and over were half as likely as those with men aged 24 and younger to conceive within a year.

Sir Paul McCartney, who became a father at 61, and John Humphrys, who did so at 56, are the exceptions, not the rule.
In another study, published two years ago, it was also found that the offspring of men aged 40 and over were nearly six times more likely to suffer from autism than those with fathers under 30.

Other research has found that men aged 50 and over are more likely to have children with Down’s syndrome, or who may develop schizophrenia.
‘I think a man who wants children who has reached 35 should get a move on,’ says Christopher Barratt, professor of reproductive medicine at the University of Dundee.

‘People say I’m not in the right relationship, I haven’t got enough money, or the car isn’t big enough.
‘In reality, you have never quite got what you want. It’s hard to beat biology, and increasingly we are seeing that applies to men as well.’
My fiancee Linda recently turned 30. She enjoys her job as a science journalist, and we have no immediate plans to start a family.

However, I’m starting to wonder whether it is my biological clock rather than hers we should keep track of, which explains how I came to make an appointment to have my semen analysed at Andrology Solutions private fertility clinic in London.
‘In the past it was only women who had maybe focused on their careers - and did not have a partner - who worried about leaving it too late to start a family,’ says Dr Sheryl Homa, the clinic’s scientific director, when I returned two weeks later for my results.
‘But now we’re seeing more men who want to have children but who are not in a relationship and are concerned that time is slipping by.’
Semen analysis involves measuring sperm count, motility - or how lively it is - and its morphology or shape.

Some research suggests older men have semen that contains less sperm, and that their sperm is more likely to be sluggish and abnormally shaped.

However, other studies have failed to detect these effects.
‘Even if semen quality declines with age, it would have to do so a lot before there’s an impact on the ability of a man to conceive,’ says Allan Pacey, a senior lecturer in andrology at Sheffield University.
Dr Homa said my count was high and motility was good. In most men, about 80 per cent of sperm cells have abnormalities that mean they have less chance of fertilising an egg.

I have a slightly higher number of such abnormalities.

No one knows why - it could be genetic or it could be down to diet. I am lucky as the effects are balanced out by my high count.
On average, 84 per cent of couples conceive naturally within a year if they have sex regularly without contraception.

National guidelines state that GPs should refer couples for tests, including semen analysis, after a year of unsuccessfully trying to conceive.

A man who is simply curious, such as me, has to pay about £75 for a test at a private clinic.
Some scientists believe higher levels of damage in sperm DNA could play an important role in undermining fertility in older men.

In the constant production of sperm cells, a single cell called a gametocyte divides into two, each ‘half’ becoming a new sperm.
During this process - meiosis --genetic material is divided and abnormalities can occur, rendering the new cells unviable.

The older men become, the more likely this is to occur.

Exposure to heat, chemotherapy treatment, radiation, genital tract inflammation, and smoking can also cause DNA damage-Some private clinics offer DNA damage tests, but scientists disagree on which tests are the more accurate and what level of damage triggers infertility.

At £300, such tests are thought to be helpful only in certain specific circumstances.
Men trying for a baby are advised to minimise alcohol intake. The evidence on caffeine is mixed but experts recommend those having more than three drinks of coffee, tea or cola a day should cut back.
There are also links between poor sperm quality and smoking, tight underwear, recreational drugs, anabolic steroids and hot baths.
Folate, one of the B vitamins, is important to women before and during pregnancy.

It is found in foods such as broccoli, sprouts, asparagus, peas and brown rice. It is also believed to be good for sperm quality.
Zinc, contained in meat, shellfish, dairy foods, bread and cereal products, is found in high concentrations in sperm and is needed to make the outer layer and tail of sperm.
I’m in a pensive mood as I leave the clinic clutching my results. I watch a group of young children playing in a park.
Discovering, from the results, that I am able to reproduce is a relief.

Maybe it’s time to eat more greens, throw out the games console and think about putting my fertility to use while I still can.


Friday, December 12, 2008

New study backs parent age-autism link

New study backs parent age-autism link

Last Updated: 2008-12-12 9:12:21 -0400 (Reuters Health)

By Anne Harding

NEW YORK (Reuters Health) - Advanced parental age does indeed appear to boost autism risk in children, and the risk is seen with both mothers and fathers, new research shows.

"What we found was that actually it's both parents age, and when you control for one parent's age you still see the effect of the other parent's age, and vice versa," Dr. Maureen Durkin of the University of Wisconsin School of Medicine and Public Health in Madison, the lead researcher of the study reported in the American Journal of Epidemiology, told Reuters Health.

The findings may offer clues to understanding the causes of autism and why it's on the rise, but they shouldn't be used to guide family planning decisions, Durkin said. Even though the oldest child born to two older parents is three times as likely to be autistic than a middle or youngest child with younger parents, she explained, there's still a 97 percent chance that the higher-risk child will be perfectly fine. "The vast majority of children don't develop autism," she emphasized.

Several studies have suggested links between a father's age or the age of both parents and a child's likelihood of having autism. The current study included twice as many autism cases as any other research on this issue to date, which made it possible to tease out the effects of both maternal and paternal age.

The researchers looked at 253,347 children born in 1994 at 10 sites included in the Centers for Disease Control and Prevention's Autism and Developmental Disabilities Monitoring Network. There were 1,251 children who met standard criteria for an autism spectrum disorder at age 8 for whom information on both parents' age was available.


Copy Number Variation and Schizophrenia (Paternal Age)

Schizophrenia Bulletin Advance Access originally published online on November 5, 2008
Schizophrenia Bulletin 2009 35(1):9-12; doi:10.1093/schbul/sbn147

© The Author 2008. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email:

Copy Number Variation and Schizophrenia
David St Clair1,2
2 Institute of Medical Sciences, University of Aberdeen

1 To whom correspondence should be addressed; David St Clair, Professor of Psychiatry, University of Aberdeen, Institute of Medical Science, Foresterhill, Aberdeen, AB25 2ZD, email:

Over the last 12 months, a series of major articles have reported associations with schizophrenia of copy number variants at 1q21, 15q11.2, 15q13.3, 16p11.2, 22q12, and Neurexin 1 loci. These are rare high-penetrant mutations that increase risk not only of schizophrenia but also of a range of other psychiatric disorders including autism and mental retardation. In some cases, the same phenotype can occur irrespective of whether the copy number variant causes a deletion or duplication. Some of these mutations occur at very high rates in human populations, but because of reduced fecundity associated with major psychiatric disorders the overall frequency in the population remains low. These new findings raise fundamental clinical and scientific questions concerning classification of major neuropsychiatric disorders, modes of inheritance, diagnostics, and genetic counseling. Although the loci identified so far account for only a small proportion of cases, many more are likely to be discovered over the next few years. A major focus of research will be to identify the key, the genetic and environmental determinants of schizophrenia risk in carriers of these copy number variants, and to discover whether their rates of mutation are unstable or fixed.

Keywords: schizophrenia / genome / CNV

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Monday, December 01, 2008

Paternal age: are the risks of infecundity and miscarriage higher when the man is aged 40 years or over?

1: Rev Epidemiol Sante Publique. 2005 Nov;53 Spec No 2:2S47-55.Related Articles, Links
Paternal age: are the risks of infecundity and miscarriage higher when the man is aged 40 years or over?

De La Rochebrochard E, Thonneau P.

Unité Inserm-Ined 569, Hôpital de Bicêtre, 82, rue du Général-Leclerc, 94276 Le Kremlin-Bicêtre.

BACKGROUND: Maternal age of 35 years or over is a well-known risk factor for human reproduction that has been extensively investigated by demographers and epidemiologists. However, the possibility of a paternal age effect has rarely been considered. We carried out review of the literature to investigate the effect of paternal age on the risks of infecundity and miscarriage. METHODS: We carried out a MEDLINE search and checked the exhaustiveness of our reference list. RESULTS: We identified 19 articles analysing the effect of paternal age. Epidemiological studies provided evidence that paternal age older than 35-40 years affects infecundity. However, the few studies based on data from assisted reproductive techniques (especially IVF with ovum donation) do not confirm this finding. All studies analysing the effect of paternal age on the risk of miscarriage showed an increased risk in men aged 35-40 years or over. Other studies have shown some evidence for a paternal age effect on late foetal deaths. CONCLUSION: The risks of infecundity and miscarriage increase with paternal age. Two main hypotheses can be considered. First, these risks increase after the age of 35-40 years. However, a later paternal age effect (after 45-50 years) cannot be excluded. Second, due to the interaction of the ages of the two partners, the risks of infecundity and miscarriage may be higher when both partners are older (woman aged 35 years or over and man aged 40 years or over).

Publication Types:

PMID: 16471144 [PubMed - indexed for MEDLINE]