Can a parent get a judge to overturn a denial of paternity ruling?

Parents were never married but both signed an acknowledgement of paternity, but later on the father after trying to get custody decided to deny paternity and the mother who really feared the father and simpy wanted to case to go away signed that form which was entered into judgement without DNA testing but now the mother wants to obtain a DNA tets to reastablish paternity. The child was born in TX but the ruling was made by a judge in MA