DNA aids MIA identification.

The cold that gripped the Korean peninsula in late 1950 was one of the worst on record. Thousands of United Nations troops were prepared for the final push to end the Korean War by Christmas, as Gen. Douglas MacArthur had promised. They were just beginning to celebrate Thanksgiving when the war turned drastically.

The lightning intervention by as many as a million Chinese forces not only turned the tide of war, it swallowed up thousands of men who disappeared in the din and fog of desperate battle.

During the frantic fighting, some 8,000 Americans went missing in action. There was hope that their fate would be known when relations with North Korea warmed in the late 1990s. But in recent years, the United States has been denied access to some battle sites because of tensions with North Korea.

Although recovery efforts have been hampered, the joint POW/MIA Command's Central Identification Laboratory (JPAC/CIL) in Hawaii is working to identify the remains of hundreds of Americans from that war.

During its last operations in North Korea, a JPAC recovery team found six sets of remains near the Chosin Reservoir, the scene of heavy fighting involving Chinese and U.S. troops during the last months of 1950. A second team recovered a set of remains from along the Chong Chon River 60 miles north of Pyongyang.

In 33 joint recovery operations beginning in 1996, the teams have recovered 229 sets of remains believed to be those of U.S. soldiers missing in the Korean War. Recovery, however, is only the beginning of the process. There is a concerted effort to identify the remains using the latest scientific technology and notify the next of kin of those who vanished decades ago.

Researchers use mitochondrial DNA (mtDNA) testing to identify the remains of those recovered from Korea. The mtDNA can be taken from a living maternal relative of an MIA, including mother, brothers and sisters, grandmother, and others who share the mother's bloodline. This direct maternal line helps identify MIA remains because mtDNA is identical as it spans generations.

Since 1991, the Armed Forces DNA Identification Laboratory (AFDIL) in Rockville, Md., has worked with the Central Identification Laboratory to identify the remains of missing service members. More than 350 identifications were made from 2001-2005, and in 75 percent of those cases DNA analysis played a significant role in the successful return of service members to their families.

The AFDIL helped identify the remains of Tsar Nicholas II of Russia, who was assassinated and buried in 1918. It was also used to identify the remains of three Civil War soldiers.

Former Department of Defense Registry Director Brion C. Smith helped pioneer the process of using mtDNA to identify old remains by extracting it from the teeth of a known Civil War soldier. "We went to the museum collection at Walter Reed Army Hospital to try the technique on teeth and then returned them undamaged," Smith said. "It was the first extraction of mtDNA from teeth." The mtDNA can also be extracted from skeletal remains.

The use of mtDNA is crucial in identifying remains from the Korean War. Smith said that 200 sets of remains were returned by North Korea between 1991 and 1994, and that "any context of recovery is lost. The remains are commingled, and there's no real guarantee that they are all Americans," he said.

"The mtDNA testing verifies identification," Smith said. "Without it, there is very little hope of identifying these individuals."

"Many times there is other evidence that can be used to help identify MIA remains," he said. "Plane parts, dog tags, and other information. In about half of the World War II and Vietnam cases, we don't need mtDNA. In Korea, it's a different story."

The mtDNA testing is a long, painstaking process, which can take up to three months to complete.

The AFDIL is collecting mtDNA samples from MIA family members to help the identification process. "We need two tubes of blood from a known maternal relative," Smith said. So far, the AFDIL has more than 6,700 samples representing 4,100 Korean War MIAs.

"The Department of Defense is spending a lot of time and effort to make sure there will be no more MIAs," Smith said. "I hope MIA families would be reassured by the efforts that are still going on. Korea is not the forgotten war and neither are the Korean War MIAs. There is a widespread effort to rectify that."

For more information about providing a mtDNA sample to the AFDIL, maternal relatives of MIAs are asked to contact the USAF Missing Persons Branch 800-531-5501; Department of the Army 800-892-2490; Headquarters U.S. Marine Corps 800-847-1597; or Department of the Navy 800-443-9298.