Researchers have discovered how three genes contribute to abnormal growth, making a breakthrough that will improve the understanding of many disorders such as fetal and childhood growth delays, abnormal development of body parts and cancer.
“As a result of the Human Genome Project, we know the basic identity of essentially all the genes in the human body, but we don’t automatically know what they do in detail,” Mark Samuels, DMD, of the University of Montreal’s Department of Medicine and the Sainte-Justine University Hospital Research Centre and lead researcher, stated in a press release. “It’s like opening your car and seeing the parts, but not knowing what each one does. When a part breaks however, you learn how it fits with the rest of the machine. Working with people who have specific health or development problems linked to specific genes enables us to see how those genes contribute to our bodies’ development and functioning.”
In this case, the team of researchers characterized the molecular basis in patients who suffer from Meier-Gorlin Syndrome (MGS), a rare disorder that is characterized by short stature, small ears, and absent or underdeveloped knee-caps. MGS is a classic single-gene disorder, meaning it is related to mutations in individual genes, although in the case of MGS different patients surprisingly seem to carry mutations in any of three different genes.
The genes are known to play a critical role in correctly copying DNA. Cells reproduce by dividing in two. All the chromosomes must also be duplicated. This process is tightly controlled to prevent having too many or too few copies of large segments of the genome.
“This seems to be the first example of any naturally occurring, inherited mutations identified in this set of important regulatory genes in any mammal. Finding the genes is a great example of the value of this type of research,” Samuels said. “We learn the cause of the disease, and discover new things about our cellular function. However we still have a lot to learn about why mutations in these genes lead to the specific consequences in Meier-Gorlin patients.”
There are 20 to 25,000 genes in the human genetic sequence, and they do not necessarily each correspond to a specific function or group of functions, or indeed to a single disease. The same gene can have subtle effects on a number of bodily functions. Moreover, in complex genetic diseases – diabetes, for example – environment and lifestyle have as much or more of an impact on health than a person’s genetic background.
“Understanding rare genetic conditions like MGS is important to the general public for two reasons,” Samuels stated. “Firstly, they provide insight into how our genes, and therefore our bodies, work. Secondly, although there are few people concerned for each particular disorder, in sum all patients with genetic conditions consume substantial amounts of health resources, and by diagnosing them more quickly, we can improve patient management and reduce the strain on the health care system.”