A mutant form of GALNT2 gene helps people clear fat from their systems, suggests study.
The report shows how the mutant gene influences metabolism in this way.
"It looks like this might be something good to have," said Jan Albert Kuivenhoven of the University Medical Center Groningen in The Netherlands.
But it remains to be ascertained whether the people he studied will enjoy a lower incidence of heart disease or other health benefits.
The new findings are also a win for genome-wide association studies, which have been under fire recently for their failure to explain many human diseases and traits.
"It shows these studies can help us identify new biological roots."
Kuivenhoven said that epidemiological studies have led to the notion that triglycerides and LDL cholesterol are bad for us while HDL cholesterol is good.
Drugs designed to lower 'bad' LDL cholesterol are effective in treating heart disease, and, following on that same logic, efforts are underway to raise HDL cholesterol.
In the current study, Kuivenhoven and his colleague G. Kees Hovingh studied two families with unusually high HDL cholesterol and low triglycerides. They also put together a list of all the genes they suspected might play a role in their distinctive lipid profiles and sequenced them.
On that list was GALNT2, a gene that had turned up before in genome-wide association studies (GWAS) as a candidate lipid metabolism gene.
The new sequencing effort identified a mutation in GALNT2. When GALNT2 mutation carriers drank pure cream, they were better able to clear those triglycerides than noncarriers were, the report showed.
The findings reveal an unexpected and exciting link between lipid metabolism and the sugar modification of proteins (a process known as glycosylation).
The study has been published in the December Cell Metabolism, a Cell Press publication.