I would file a new I-130. Indicate that you are willing to go through DNA testing if the government is not satisfied with your documentary proof of your relationship.
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If you have proof that your response was delivered on time, such as a FedEx tracking number and delivery confirmatoin, then you may want to request reopening by the USCIS on its own motion. You may be able to do this through an attorney or through the immigration liaison person at a senator or congressperson's office. However, if the USCIS doesn't reopen the case on its own in this way, and you want to preserve this I-130, then you'll have to file the motion with the filing fee within the 30 days. If you cannot prove that you responding timely to the request for evidence, then this would probably be a waste of your time and money. But if you can prove your timely response, then this would preserve the priority date for this I-130. Filing a new I-130 would get you a new priority date, which may be much later than the original I-130.Ask a similar question