Brig. Gen. Manaf Tlass, a member of the elite Republican Guards and a son of a former defense minister, slipped out of the country and abandoned the Assad regime.
Tlass was one of the highest ranking Sunni Muslims in the Assad government, which is dominated by members of the Alawite sect. Tlass' father, who now lives in Paris, was a close confidante of former Syrian strongman Hafez Assad, who is the father of the current Syrian president.
Gen. Manaf Tlass and the Syrian president had been childhood friends.
"The defection of Manaf Tlass is a big set back for the Assad regime," said Mohammed Balout, a long time expert on Syria on the Lebanese daily Al Saffir.
Balout called it a "symbolic strategic defeat" and believed it would lead to more defections.
Tlass was the head of Brigade 105 of the Republican Guard in charge of protecting the capital Damascus.
The general's defection would have been "more powerful defection of his brigade defected with him," Balout said.
Without those troops, however, the defection does not pose a threat to Assad.
"Manaf was under home arrest for almost two years and he is not part of the security leaders in charge of the crackdown on the syrian uprising," Balout said.
Faysel Jaloul, an expert on Syria and researcher who is based in Paris, said the defection "no doubt is a symbolic and media victory for the opposition." When Assad's father died in 2000, the Tlass family remained loyal to the Assad family and Manaf Tlass helped engineer Bashir Assad's succession.
But his defection will have little impact on the events in Syria, Jaloul said. After Bashar Assad became president, the Tlass family was sidelined and is not as influential as it was during of the elder Assad.
Last month a Syrian air force pilot defected, flying his MiG21 to Jordan, which also was seen as a possible crack in the elite ranks of the regime.
Thousands of soldiers have defected to the rebels.
The Syrian uprising has reportedly cost 14,000 lives so far.