Understanding the Paternity Test Report

When we test your DNA for paternity we look for the father’s and mother’s genetic markers and match them to the child being tested.  We look for 23 markers at specific places on the child’s DNA, and then we look for matching markers in the mother and the alleged father’s DNA.  The markers will have a number.  We look for matches, and call these matching alleles.

As we know the mother’s DNA matches, so then the other match has to come from the biological father.  If the profile does not match, the tested man is excluded as being the true biological father of the child.

We test the 23 special markers and then calculate the result to see if the alleged father is excluded or not excluded as being the father.  To be the biological father there must be a match with all 23 markers.  We also calculate a Probability of Paternity.  This is the percentage likelihood that a man is an identical match between the alleles of the man and child, and this means there is a very high (greater than 99.9999%) chance of the alleged father being the father.  It is never possible to prove 100% that a man is definitely the biological father of a child, as there is always a chance, however remote, that another man in the population may have DNA types which match that child.  

There are two possible outcomes in a DNA paternity test

1. Exclusion.  – THE PERSON TESTED IS NOT THE BIOLOGICAL PARENT.  A report which states a paternity exclusion will show a minimum of 2 or more of the numbers in the matching allele column that are left blank.  When an exclusion is indicated, the probability of parentage is 0%.

2. Paternity Inclusion. – THE PERSON TESTED IS ACCEPTED AS THE BIOLOGICAL PARENT and the report says NOT EXCLUDED. The Probability of Paternity number shows the number of individuals in the Australian population that would have to be tested who may have a profile the same as the tested person.

Counselling Options

Paternity testing means that in some cases the result from the laboratory will have a large impact on the lives of the individuals being tested.  Mostly the paternity of the alleged father is confirmed, but in a small number of cases this is not so.  These results can also affect other family members and friends of the individuals being tested.  Some results will show that the person who you believed was related to you is not related to you in a biological way.  This can be a life changing result and may be difficult to understand how the family structure can be changed after the DNA test.

However, some people may have a relationship confirmed which can eliminate thoughts of uncertainty about paternity or family relationships.  The reaction to a paternity result may be relief or grief.  Counselling can help individuals when the test result is unexpected.

The children being tested for paternity need to have the testing explained to them and why it is being done.  This should be done before the testing has been done as counselling is important for the ongoing relationship with the child.  Counselling should be undertaken if the result of the paternity test is believed to have an emotional impact on the child.

Counselling by someone outside the family is sometimes easier for the child rather than discussing the issues with the immediate family members.  Paternity cases before the Family Law court will have counselling options available to them.  For cases not before the court, counselling assistance can be accessed at the following sites:


Mensline 1300 789 978  offers counselling 24 hours every day

Lifeline 131114  offers counselling 24 hours every day

Men’s Survival Centre 1300 853 437

Lone Fathers Association (02)6239  4650 / (07) 3376 2876

Dads in Distress 1300 853 437



Dr. Mary Seth Smith – private counsellor  (07) 3300 4404 

Family Law Reform Association (Chelmer) (07) 3379 2871

Men’s Rights Agency (07) 3805 5611



Burnside Fathers Support Service (02)9806 0200

DADS Australia Sydney (02) 4577 2707 Mobile 0419 986 345

Grandparents Support Group (02) 4341 7640

Lone Parents’ Support Network (02) 9720 8599

Men’s Phone Line (02) 9979 9909

Unifam Counselling & Mediation Service (02) 9891628

GRANSMobile 0418 622 120

Credit Helpline (02) 9951 5544

Men’s Health and Wellbeing Association (02) 9802 1500



Lone Fathers Association (08) 8932 3339

SOUTH AUSTRALIA Child Support Action Group (08) 8341 1225

Men’s Information and Support Centre (08) 8212 0331



Family Law Reform Party (03) 9387 7044

Grans Victoria (03) 9796 5442

Fathers for Family Equity (03) 9878 6588

Parents Without Rights (03) 9568 3349



Grandparents Support Group (08) 9332 5469

Men’s Confraternity Inc (08) 9470 1734

Men’s Equity Network (08) 9246 1102