Editing Huntington's disease (section)

===Prenatal testing===

Obtaining a [[prenatal diagnosis]] for an embryo or [[fetus]] in the womb is also possible, using fetal genetic material acquired through [[chorionic villus sampling]]. An [[amniocentesis]] can be performed if the pregnancy is further along, within 14–18 weeks. This procedure looks at the amniotic fluid surrounding the baby for indicators of the HD mutation.<ref>{{cite web|title=Predictive Testing for Huntington's Disease|url=http://predictivetestingforhd.com/testing-for-hd/prenatal-testing/amniocentesis/|access-date=7 May 2013|year=2011|url-status=live|archive-url=https://web.archive.org/web/20130122124510/http://predictivetestingforhd.com/testing-for-hd/prenatal-testing/amniocentesis/|archive-date=22 January 2013}}</ref> This, too, can be paired with exclusion testing to avoid disclosure of parental genotype. Prenatal testing can be done when parents have been diagnosed with HD, when they have had genetic testing showing the expansion of the ''HTT'' gene, or when they have a 50% chance of inheriting the disease. The parents can be counseled on their options, which include [[termination of pregnancy]], and on the difficulties of a child with the identified gene.<ref name="pmid15758612">{{cite journal | vauthors = Kuliev A, Verlinsky Y | title = Preimplantation diagnosis: a realistic option for assisted reproduction and genetic practice | journal = Current Opinion in Obstetrics & Gynecology | volume = 17 | issue = 2 | pages = 179–183 | date = April 2005 | pmid = 15758612 | doi = 10.1097/01.gco.0000162189.76349.c5 | s2cid = 9382420 }}</ref><ref>{{cite web|title=Guidelines for Genetic Testing for Huntington's Disease|url=http://dwb4.unl.edu/chem/chem869n/chem869nlinks/www.hdfoundation.org/testread/hdsatest.htm|publisher=Heredity Disease Foundation|access-date=7 May 2013|url-status=dead|archive-url=https://web.archive.org/web/20150626005614/http://dwb4.unl.edu/Chem/CHEM869N/CHEM869NLinks/www.hdfoundation.org/testread/hdsatest.htm|archive-date=26 June 2015}}</ref>

In addition, in at-risk pregnancies due to an affected male partner, noninvasive prenatal diagnosis can be performed by analyzing [[cell-free fetal DNA]] in a blood sample taken from the mother (via [[venipuncture]]) between six and 12 weeks of pregnancy.<ref name=Die-Smulders2013/> It has no procedure-related risk of miscarriage.<ref name=Die-Smulders2013/>