JUDAISM, GENETIC SCREENING AND GENETIC THERAPY

Genetic screening, gene therapy and other applications of genetic engi neering are permissible in Judaism when used for the treatment, curt, or prevention of disease. Such genetic manipulation is not considered to be a violation of God's natural law, but a legitimate implementatio n of the biblical mandate to heal. If Tay-Sachs disease, diabetes, hem ophilia, cystic fibrosis, Huntington's disease or other genetic diseas es can be cured or prevented by ''gene surgery,'' then it is certainly permitted in Jewish law. Genetic premarital screening is encouraged i n Judaism for the purpose of discouraging at-risk marriages for a fata l illness such as Tay-Sachs disease. Neonatal screening for treatable conditions such as phenylketonuria is certainly desirable and perhaps required in Jewish law Preimplantation screening and the implantation of only ''healthy'' zygotes into the mother's womb to prevent the birt h of an affected child are probably sanctioned in Jewish law. Whether or not these assisted reproduction techniques may be used to choose th e sex of one's offspring, to prevent the birth of a child with a sex-l inked disease such as hemophilia, has not yet been ruled on by modern rabbinic decisions. Prenatal screenings with the specific intent of ab orting an affected fetus is not allowed according to most rabbinic aut horities, although a minority view permits; it ''for great need.'' Not to have children if both parents are carriers of genetic diseases suc h as Tay-Sachs is not a Jewish option. Preimplantation screening is pr eferable. All screening test results must remain confidential. Judaism does not permit the alteration or manipulation of physical traits and characteristics such as height, eye and hair color, facial features a nd the like, when such change provides no useful benefit to mankind. O n the other hand, it is permissible to clone organisms and microorgani sms to facilitate the production of insulin, growth hormone, and other agents intended to benefit mankind and to cure and treat diseases.