DNA test crazy
Bedsheets, pants, panties tested for sex stains
Last year 150 people had DNA tests performed, double that of 1995. GENEVIEVE JIANG (
[email protected]) reports
SHE was hysterical and in tears.
Holding a stained NS poncho, the middle-aged woman turned up one day last year at the Health Sciences Authority (HSA) at Outram Road insisting on getting it tested.
She had found stains on the poncho (which can double as a groundsheet) at home, and suspected that her husband had been unfaithful - with another man.
Mrs Tan Wai Fun, 50, head of HSA's DNA Profiling Laboratory, recalled the scene: 'There were stains on different parts of the poncho and she wanted to get it tested to see if there was semen belonging to more than one man.
'She suspected that her husband was gay.'
But no DNA tests were done, because the woman couldn't afford the fees.
A basic test to confirm that the poncho contained semen would have cost her $300. A more detailed test to determine if the semen belonged to two different men would have cost about $2,000.
'I ended up playing counsellor for close to an hour,' said Mrs Tan. 'She was obviously distraught and just needed a listening ear.'
Due to the confidential nature of DNA tests, HSA wouldn't identify the clients.
Suspicious spouses seeking the truth make up only a handful of the cases they see every year - usually fewer than 10.
Mrs Tan Wai Fun
'Although they are the minority, these are often the cases that stick in our minds,' said Mrs Tan. 'People come in with all sorts of things for testing. Some with squashed balls of tissue, with bedsheets, with their spouse's shirt and pants, and some husbands even bring in their wives' stained underwear.
'We also get calls asking us how to store the so-called specimens.'
Mrs Tan said the stained fabric can be dried and placed in a clean envelope, and can be stored for several weeks.
Once, a man brought in a ball of tissue paper for testing.
He had been away on holiday for a week, and when he returned home he found it on the floor of his toilet at home.
He suspected his wife had been unfaithful while he was away.
The results showed that there were indeed semen stains on the tissue.
For the man, there was no need for DNA profiling and matching to be conducted. The positive result was enough for him to conclude that his wife had been unfaithful.
REGULAR CUSTOMER
And sometimes, even when the results are negative, clients are not satisfied.
Dr Christopher Syn, 33, one of six forensic scientists at HSA's DNA profiling lab, recalled: 'There was a man who came in three times, with different items each time. He was convinced that his wife had committed adultery.
'But each time, we couldn't find any semen stains. Still, he was unconvinced.
'He has become our regular customer. We see him about once every three to four months.'
Since DNA testing was made available to the public in April 1990, more and more people involved in divorce, custody battles and child-maintenance cases have turned to the tests. Some also want to determine or confirm genetic relationships for reasons like immigration requirements.
For example, to get a US green card through a family programme, you must prove you are biologically related to a US citizen.
Each person has around 30,000 genes, which are carried on twin strands of DNA. DNA is unique to each person, and doesn't change throughout their life.
Half the DNA comes from the biological father and the other half from the biological mother.
In 1991, there were 15 cases of DNA testing, most of them for paternity tests. This number grew to 87 in 1995, and almost doubled to 171 in 2002.
Last year, 150 people went in for DNA testing, again mostly related to doubts over paternity.
The cost varies.
To check for the presence of semen on a small item like underwear or tissue costs between $250 and $300.
A DNA test to determine the paternity of a child costs $925.
Christopher Syn
Often, when results are out, the scene is one of denial and heartbreak.
Mrs Tan said: 'One of my most memorable cases was that of an elderly man from India with three adult sons.
'The results showed that the first son wasn't his.
'He kept repeating that it can't be true, that his wife was a good woman, and that we had made a mistake.'
He insisted that the test was affected by his son's drinking and smoking habit, and agreed to pay for a second test.
The results were the same.
'There was a heartbreaking moment when the elderly man brought all this son's belongings - from his clothes to his primary school report books - telling us about what a good boy his son was. He was in denial. It was obvious to all this was a shattered man.'
Mrs Tan said DNA testing is 99.9 per cent accurate. Test reports can be ready within three weeks.
In paternity cases, blood samples are collected from the child, mother and alleged father. The DNA is extracted and purified.
A genetic analyser then compares the DNA profile of the child with that of the mother, to determine which half was inherited from her.
The other half must have been inherited from the child's biological father, so if the patterns match, the person has to be the biological father.
If not, it's someone else.
CLINTON & THAT BLUE, STAINED DRESS
DNA tests disproved former US President Bill Clinton's denials that he'd had a sexual relationship with White House intern Monica Lewinski.
The test revealed that DNA from his blood matched that of semen stains found on her infamous blue dress.
Revelations of illicit liaisons have also emerged from DNA tests here.
In a custody case in 2001, a baby was found to have been fathered by the mother's lover, rather than her husband.
Under the Women's Charter, that meant her husband had no rights over the child and the mother won custody.
Last month, in another custody battle, a woman revealed in court that her two older children were not fathered by her husband.
Apart from paternity tests, DNA testing can be used to identify victims such as those of the Sep 11 terrorist attacks and the tragic SQ 006 crash in 2000.
SOLVES CRIMES
It can also be used to solve criminal cases - sometimes years later.
In 2000, DNA evidence helped catch a rapist of two young sisters in Derby, UK, 13 years after the attacks.
Closer to home, DNA helped put a name to a skeleton found in a warehouse along Tong Watt Road last year.
SOurce: NP
