In its interim report, the commission also said there was not enough evidence to support widespread rape allegations.
It did not mention claims that security forces had been killing people.
There have been repeated allegations of abuses of Rohingya people since a military counter-insurgency campaign was launched in Rakhine in October.
Some have even said the state's actions amount to ethnic cleansing, and Myanmar's de facto leader Aung San Suu Kyi, a Nobel peace laureate, has faced international criticism.
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The commission, set up by the Myanmar government and led by a former general, Myint Swe, is due to make its final conclusions before the end of January.
But, in its interim findings, it dismissed allegations of genocide on the basis that there are still Rohingya Muslims living in Rakhine and that Islamic religious buildings have not been destroyed.
It said it had so far found "insufficient evidence" that anyone had been raped by security forces, despite widespread claims. Accusations of arson, arbitrary arrest and torture are still being investigated.
Strangely, the commission made no mention of the most serious claim - that Burmese security forces have been killing civilians as collective punishment for attacks by Rohingya militants, the BBC's Myanmar correspondent Jonah Fisher reports.
Three months since this crisis began, little progress appears to have been made to solve it, he notes. The report says hundreds of Rohingya have been arrested but armed militants are still moving around easily and that looted weapons have yet to be recovered.
Earlier in the week, several police were detained after a video surfaced appearing to show officers beating Rohingya Muslims during a security operation in November.
The admission that security forces may have carried out abuses is an unusual development, as leaders have previously insisted they are following the rule of law.
Rakhine state is closed to journalists and investigators, making it difficult to independently verify any allegations.
The estimated one million Muslim Rohingya are seen by many in mainly Buddhist Myanmar as illegal migrants from Bangladesh. They are denied citizenship by the government despite tracing their ancestry back generations.
Communal violence in Rakhine state in 2012 left scores dead and displaced more than 100,000 people, with many Rohingya still remaining in decrepit camps.
They face widespread discrimination and mistreatment.
Hundreds of thousands of undocumented Rohingya are estimated to live in Bangladesh, having fled Myanmar over decades.
Bangladesh says around 50,000 Rohingya have crossed its border over the past two months.
The situation has drawn global condemnation. Over a dozen Nobel laureates wrote to the UN Security Council demanding action to stop the "human tragedy amounting to ethnic cleansing and crimes against humanity" in northern Rakhine.
A commission set up by Myanmar's government says it has so far found no evidence of genocide against Rohingya Muslims in Rakhine state.