Overcoming cardiac pacemaker "source-sink mismatch"

Instead of complication-prone electronic cardiac pacemakers, biomedical engineers at Georgia Tech and Emory envision the creation of “biological Read more

Hope Clinic part of push to optimize HIV vaccine components

Ten years ago, the results of the RV144 trial– conducted in Thailand with the help of the US Army -- re-energized the HIV vaccine field, which had been down in the Read more

Invasive cancer cells marked by distinctive mutations

What does it take to be a leader – of cancer cells? Adam Marcus and colleagues at Winship Cancer Institute are back, with an analysis of mutations that drive metastatic behavior among groups of lung cancer cells. The findings were published this week on the cover of Journal of Cell Science, and suggest pharmacological strategies to intervene against or prevent metastasis. Marcus and former graduate student Jessica Konen previously developed a technique for selectively labeling “leader” Read more

arginase deficiency

Genomics plus human intelligence

Emory geneticists Hong Li and Michael Gambello recently identified the first pediatric case of a rare inherited metabolic disorder: glucagon receptor deficiency. Their findings, published in Molecular Genetics and Metabolic Reports, show the power of gene sequencing to solve puzzles – when combined with human intelligence. Although the diagnosis did not resolve all the issues faced by the patient, it allowed doctors to advise the family about diet and possible pancreatic tumor risk.

The family of a now 9-year-old girl came to Li when the girl was 4 years old. Based on newborn screening, the girl had been diagnosed with a known disorder called arginase deficiency. Arginase breaks down the amino acid arginine; if it is deficient, arginine and toxic ammonia tend to accumulate. At birth, the girl had high arginine levels – hence the initial diagnosis.

The girl had a history of low body weight, anorexia and intermittent vomiting, which led doctors to place a feeding tube through the abdominal wall into her stomach. For several years, she was given a special low-protein liquid diet and supplements, aimed at heading off nutritional imbalance and tissue breakdown. However, she did not have intellectual disability or neurological symptoms, which are often seen with arginase deficiency.

In fact, her blood amino acids, including arginine, were fully normalized, and a genetic test for arginase deficiency was normal as well.  These results were perplexing. By reviewing all the clinical, biochemical and molecular data, Li concluded the girl did not have arginase deficiency, and began looking for an alternative diagnosis. Read more

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