any existing techniques on human genetic modification

[steelcat]

are there any existing techniques on human genetic modification
for adult human.

[jonmoulton]

You need to be careful with the distinction between "existing" techniques and "approved" techniques. No techniques involving human DNA manipulation have made it through clinical trials (dangerous to make statements like that, someone will probably surprise me...), so no techniques are "approved". However, techniques that altered DNA have entered clinical trial -- I would call that an existing, but unapproved, technique. Look into the chloride channel (CFTR) gene therapies using viral delivery for cystic fibrosis.
http://en.wikipedia.org/wiki/Cystic_fibrosis#Transplantation_and_gene_therapy