New metabolic disease discovered

Last Updated: Friday, September 6, 2013 - 18:16

Washington: Scientists have discovered a rare new disease related to an inability to process Vitamin B12.

An international team of scientists, including University of Colorado School of Medicine and Children`s Hospital Colorado researchers, identified the rare but devastating disorder.

A 9-year-old Colorado boy named Max Watson, who because of his metabolic disease uses a computer to communicate, became the first patient in whom this discovery was made.

"Some people with rare inherited conditions cannot process vitamin B 12 properly," said CU researcher Tamim Shaikh, a geneticist and senior author of the study.

"These individuals can end up having serious health problems, including developmental delay, epilepsy, anemia, stroke, psychosis and dementia," Shaikh said.

The discovery, published in The American Journal of Human Genetics, illustrates the complex and relatively new realm of medical discovery where researchers peer into the genetic make-up of patients to discern what went wrong to cause a disease.

Vitamin B 12 also is called cobalamin. The new disease is called cobalimin X, or cblX.

Obtained from foods such as milk, eggs, fish and meat, B 12 is essential to human health because it helps the body convert food into fuel. It`s vital to the nervous system and for making red blood cells.

Max was born with symptoms that looked like he had a B 12 problem called cobalamin C deficiency or cblC for short, which, like its newly discovered counterpart, can show up in utero.

The gene for cblC had been discovered by researchers who studied several hundred patients with similar symptoms. A few of those patients, however, did not have the genetic mutation that that was common to the cblC patients. And some, like Max, had symptoms that didn`t quite match up.

"We knew from early on that something was unusual about this patient," said Johan Van Hove, a CU professor in the Department of Pediatrics, who saw Max when the boy was just a few months old.

Max was labelled as having cblC - but Van Hove and others on a team of metabolism experts at Children`s Hospital Colorado had their doubts. Some of Max`s symptoms seemed too severe for that diagnosis.

So Shaikh, an associate professor in the medical school`s pediatrics department, and CU colleagues, used next generation genetic sequencing to delve into Max`s DNA.

They also looked at genes of patients who didn`t fit the cobalamin C model, obtained from partners at the National Institutes of Health, and in Canada and Switzerland.

All of those patients carried mutations that hadn`t been identified before. The problem was due to flaws in a gene designed to control the workings of an enzyme that, in turn, helps the body metabolise B 12, researchers said.

PTI



First Published: Friday, September 6, 2013 - 18:16

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