Rethinking the Genetic Theory of Inheritance

Jan 18, 2009

Scientists at the Centre for Addiction and Mental Health (CAMH) have detected evidence that DNA may not be the only carrier of heritable information; a secondary molecular mechanism called epigenetics may also account for some inherited traits and diseases. These findings challenge the fundamental principles of genetics and inheritance, and potentially provide a new insight into the primary causes of human diseases.

Your mother's eyes, your father's height, your predisposition to disease-- these are traits inherited from your parents. Traditionally, 'heritability' is estimated by comparing monozygotic (genetically identical) twins to dizygotic (genetically different) twins. A trait or disease is called heritable if monozygotic twins are more similar to each other than dizygotic twins. In molecular terms, heritability has traditionally been attributed to variations in the DNA sequence.

This video is not supported by your browser at this time.
Dr. Art Petronis, head of the Krembil Family Epigenetics Laboratory at the Center for Addiction and Mental Health, discusses new evidence that DNA may not be the only carrier of heritable information; a secondary molecular mechanism called epigenetics may also account for some inherited traits and diseases. These findings challenge the fundamental principles of genetics and inheritance, and potentially provide a new insight into the primary causes of human diseases. Video: Center for Addiction and Mental Health


CAMH's Dr. Art Petronis, head of the Krembil Family Epigenetics Laboratory, and his team conducted a comprehensive epigenetic analysis of 100 sets of monozygotic and dizygotic twins in the first study of its kind. Said Dr. Petronis, "We investigated molecules that attach to DNA and regulate various gene activities. These DNA modifications are called epigenetic factors."

The CAMH study showed that epigenetic factors - acting independently from DNA - were more similar in monozygotic twins than dizygotic twins. This finding suggests that there is a secondary molecular mechanism of heredity. The epigenetic heritability may help explain currently unclear issues in human disease, such as the presence of a disease in only one monozygotic twin, the different susceptibility of males (e.g. to autism) and females (e.g. to lupus), significant fluctuations in the course of a disease (e.g. bipolar disorder, inflammatory bowel disease, multiple sclerosis), among numerous others.

"Traditionally, it has been assumed that only the DNA sequence can account for the capability of normal traits and diseases to be inherited," says Dr. Petronis. "Over the last several decades, there has been an enormous effort to identify specific DNA sequence changes predisposing people to psychiatric, neurodegenerative, malignant, metabolic, and autoimmune diseases, but with only moderate success. Our findings represent a new way to look for the molecular cause of disease, and eventually may lead to improved diagnostics and treatment."

An advance online publication of this study will be available on the Nature Genetics website on January 18, 2009.

Source: Centre for Addiction and Mental Health

Explore further: Innovative 'genotype first' approach uncovers protective factor for heart disease

add to favorites email to friend print save as pdf

Related Stories

Molecular gate that could keep cancer cells locked up

7 hours ago

In a study published today in Genes & Development, Dr Christian Speck from the MRC Clinical Sciences Centre's DNA Replication group, in collaboration with Brookhaven National Laboratory (BNL), New York, ...

Taking great ideas from the lab to the fab

7 hours ago

A "valley of death" is well-known to entrepreneurs—the lull between government funding for research and industry support for prototypes and products. To confront this problem, in 2013 the National Science ...

SR Labs research to expose BadUSB next week in Vegas

8 hours ago

A Berlin-based security research and consulting company will reveal how USB devices can do damage that can conduct two-way malice, from computer to USB or from USB to computer, and can survive traditional ...

Recommended for you

Study clarifies parents as source of new disease mutations

Jul 31, 2014

Scientists have long speculated that mosaicism – a biological phenomenon, in which cells within the same person have a different genetic makeup – plays a bigger role in the transmission of rare disease mutations than ...

How black truffles deal with the jumpers in their genome

Jul 31, 2014

The black truffle uses reversible epigenetic processes to regulate its genes, and adapt to changes in its surroundings. The 'methylome' - a picture of the genome regulation taking place in the truffle, is published in the ...

Gene research targets scarring process

Jul 28, 2014

Scientists have identified three genes that may be the key to preventing scar formation after burn injury, and even healing existing scars.

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

gopher65
3 / 5 (1) Jan 18, 2009
This is very interesting research.
Ashibayai
2 / 5 (1) Jan 19, 2009
I thought this pretty well understood already. Though, I do find this specific experiment to be very interesting.