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Vol. LXIII, No. 4
February 18, 2011
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Digest
  Dr. George Chacko  
 

NHGRI-supported researchers have sequenced the genome of the orangutan, which belongs to the primate family.

 

Grantees Publish Orangutan Genome Sequence

It is easy to feel a kinship with orangutans when looking into their soulful eyes and observing their socially complex behavior. Perhaps that’s because orangutans and humans share 97 percent of their DNA sequence, according to an analysis of the great ape’s genome reported by an international group of scientists.

Orangutans, known for their distinctive auburn hair, are primarily tree dwellers native to the southeast Asian islands of Sumatra and Borneo. The DNA sequence published in the Jan. 27 issue of Nature is from a female Sumatran (Pongo abelii) orangutan. In addition, five Sumatran and five Bornean (Pongo pygmaeus) orangutan genomes were sequenced at a less detailed level. The orangutan is the third non-human primate to have its genome sequenced, after the chimp and rhesus macaque. Of the great apes, orangutans are the most distantly related to humans, while chimpanzees are the most closely related.

Researchers can now leverage the orangutan genome sequence to learn more about the biology of this endangered species and to identify what has been added or deleted in the evolution of primate and human genomes that may have contributed to unique human characteristics.

Scientists Identify Genetic Cause of New Vascular Disease

Researchers at the Undiagnosed Diseases Program have identified the genetic cause of a rare and debilitating vascular disorder not previously explained in the medical literature. The adult-onset condition is associated with progressive and painful arterial calcification affecting the lower extremities, yet spares patients’ coronary arteries. The new disease finding was published Feb. 2 in the New England Journal of Medicine.

The rare arterial condition caused by calcium buildup in arteries below the waist and in the joints of a patient’s hands and feet has been observed in nine individuals from three unrelated families, who are the only people known to have the disorder. The researchers refer to the condition as ACDC, or arterial calcification due to CD73 deficiency. Although symptoms of the disorder include leg and joint discomfort, medical evaluations of the patients ruled out rheumatoid arthritis or other joint-related problems. Genetic analyses performed by the researchers suggested a novel disorder and pinpointed the cause of the condition as mutations, or variants, in the NT5E gene.

“This is the first novel disease discovery identified through the collaborative and interdisciplinary approach employed by clinical researchers in the NIH Undiagnosed Diseases Program,” said NIH director Dr. Francis Collins. “This disorder previously baffled the medical field and evaded diagnosis when conventional methods were used.”

“Vascular calcification often results from poor diet and lack of exercise,” said study coauthor Dr. William Gahl, director of the UDP. “The calcium buildup in arteries of our patients, however, arises because the systems to inhibit it are not working in their cells. We hope that an understanding of this faulty mechanism will guide us in providing helpful treatments for these patients.”

Level of Tumor Protein Indicates Chances Cancer Will Spread

Researchers at NIH and the University of Hong Kong have discovered that high levels of a particular protein in cancer cells are a reliable indicator that a cancer will spread.

By measuring the protein’s genetic material in tumors that had been surgically removed from patients, along with measuring the genetic material from surrounding tissue, the researchers could predict at least 90 percent of the time whether a cancer would spread within 2 years.

The findings, which appeared in the Journal of Clinical Investigation, raise the long term possibilities of new tests to gauge the likelihood that a cancer will spread and, ultimately, of a treatment that could prevent cancer from spreading.

The protein, known as CPE-delta N, is a form of carboxypeptidase E (CPE). Ordinarily, CPE is involved in processing insulin and other hormones. CPE-delta N was present in high amounts in tumors that had spread and, to a much lesser degree, in surrounding tissues.

“Testing for CPE-delta N, if combined with existing diagnostic methods, offers the possibility of more accurately estimating the chances that a cancer will spread,” said NICHD director Dr. Alan Guttmacher, whose institute supported the study. “Conceivably, a patient’s CPE-delta N levels could be a key guide in individualizing their cancer care to improve outcome.”


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