Julie Cini, spinal muscular atrophy disease carrier whose twin daughter died of the disease at one year old.

Julie Cini, spinal muscular atrophy disease carrier whose twin daughter died of the disease at one year old. Photo: Joe Armao

Julie Cini had never heard of spinal muscular atrophy before her daughter Montanna was born, limp and floppy from the mostly fatal muscle-wasting disease.

"The hospital basically told us to take our child home and love her until she died," said Ms Cini. She passed away aged 10 months. Her second daughter Zarlee, born in 2006, survived two months longer than her sister.

Before Montanna's birth Ms Cini and her husband had no idea they were unwitting carriers of the devastating disorder. Had they known they could test for such conditions "we could have spared ourselves the devastation," said Ms Cini.

While doctors have known about recessive disorders for decades, rapid improvements in genetic screening are making tests more cost-effective. From Thursday prospective parents can order a genetic test online that screens for 145 recessive disorders, such as cystic fibrosis, Tay-Sachs, and Fragile X.

As many as one in 25 people are carriers of a recessive genetic disorder, but because a carrier's health is not affected, many have no idea they can pass a disorder on, said the founder of Life Letters, medical doctor and entrepreneur Sam Prince.

While children with only one parent carrier will be born unaffected, couples who both carry a defective gene have a one in four chance their child will be born with the genetic disorder. However, the chance of two partners having the same mutation is very low.

Dr Prince said his motivation for the pre-conception test, called Tiny Letters, was to empower people to take advantage of genetic technology to make decisions about their family's health.

"It's all about informed choice. [It's about] going into your future with your eyes wide open," he said.

Couples can order the Tiny Letters test online ($900 for an individual or $1700 for a couple), but unlike other direct-to-consumer genetic tests the company will insist a GP or genetic counsellor returns the results.

"We want to do this responsibly and ethically," said Dr Prince.

Dr Barlow-Stewart, a member of the company's advisory board, believes an easily accessible test will increase peoples access to important information about their health before they get pregnant.

"Not everyone goes to talk about these things with their doctor before they get pregnant, but if it's on the web they may come across it," she said.

Other advisors include Nobel Prize winner Brian Schmidt, genetics pioneer Leslie Burnett, ethicist Simon Longstaff and David Weisbrot, who led the Australian Law Reform Commission's inquiries into the protection of genetic information and gene patenting.

Morton Rawlin, the vice-president of the Royal Australian College of General Practitioners, said it was good to see direct-to-consumer genetic test that involved GPs at the stage of the results, but people should seek the advice of their doctor before they ordered it.

He said some became deeply anxious and worried about the genetic test results.

"Just because you have a genetic marker for a condition, doesn't mean you are going to end up with that condition," he said. "There are also long-term implications, for example if the tests are discoverable by insurance companies you may end up with higher premiums".

A spokesman for the Royal College of Pathologists of Australasia, Graeme Suthers, who is an expert in genetic testing and the head of genetics for Sonic Healthcare, said he welcomed the move to integrate a test with GP care.

"On the plus side it engaging with the public… it puts the individual at the centre of their healthcare management," he said.

But he said it was important to keep in mind how inheritance of recessive disorders worked – with both partners needed to carry the gene mutation for it to be passed on. One in 25 people carrying one of the genes being tested for meant only one in 625 couples would both carry a mutation, and only in a very tiny proportion of those would both couples carry the same mutation and so run the risk of passing a condition on.

"If you were to approach this issue from the perspective of the minister for health, asking should we commit public funds for this test, I would say the answer would be 'no way, Jose,' because the chance of any major problems being averted is very low," he said. "But if you are a couple and you are interested, yes by all means… but remember, you are doing this on emotional grounds - and there is nothing wrong with that - not medical grounds."

Ms Cini, now the CEO of the Spinal Muscular Atrophy Association of Australia, hopes her experience offers a cautionary tale to others.

"If my story means anything I beg people to think about pre-conception testing," she said.

"Prevention is better than cure. It's a no brainer."