Feasibility Testing

Admin

Following our appointment with the Fertility Associates (FA) specialist, we needed to supply copies of our birth certificates or passports (including residency visas) to prove our eligibility for publicly funded treatment. The specialist then submitted a National Clinical Assessment Criteria (CPAC) for Treatment of Infertility form to the Ministry of Health on our behalf. For couples facing fertility problems, this form comprises a priority scoring system with criteria such as types of diagnosed fertility issues, age, time spent trying to conceive etc. where a score of at least 65/100 is required to be eligible for treatment. In cases like ours where hereditary disease is the concern, if there is a 25% or higher chance of passing on the disease, provided you are a non-smoker, have a BMI in the range of 18-32 and are under 39 years of age, then you qualify for treatment.

After a few emails back and forth with the FA administrator, (I wasn't taking any chances after the delays we had with Dave's results) I was told that the Ministry of Health coordinator meets with the embryology team from FA once a month to discuss ongoing cases. At this point a couple is required to undergo genetic counselling if they have not already, but the counselling we had around Dave’s testing and diagnosis proved sufficient in our case. 

Location of the ATXN 3 gene on chromosome 14:
Cytogenetic Location: 14q32.12, which is the long (q) arm of chromosome 14 at position 32.12

Feasibility

Four weeks after our initial appointment, the FA embryologist rang to let me know she was posting out the paperwork for our feasibility study, which is to be conducted by Canterbury Health Laboratories in Christchurch. Each of us and our parents were asked to have blood samples taken (which could be done at the local blood sample collection centres in Nelson) and to sign consent forms giving permission for the lab to store and test our DNA. She said that depending on how busy the lab is, the feasibility testing would probably take about a month.

The purpose of feasibility testing is to use our blood cells to conduct a trial run of the test they will hopefully eventually use on our embryos. The aim is to confirm that the mutation carried (in our case the repeating sequence in the ATXN3 gene) can be reliably detected in our embryos, and to develop the best strategy for embryo analysis. When PGD is carried out on an embryo, only a few cells are sampled for testing so the lab needs to ensure they can accurately ascertain the presence or absence of the SCA3 mutation using such a minuscule sample size.