Gender: boy
I found this information by searching on google. I explained how I arrived to this conclusion on Stage 5, but just entered on Stage 2 as told.
I found out that these were his relatives after searching google for any possible hits. I then came across the website JewishGen and it had listed all of the Majzler's they had on file. I then found Mordchaj, as well as the others I listed above. They all have the same ghetto addresses, that is why I made that conclusion.