DNA Testing

DNA testing (also called DNA profiling, DNA typing, or genetic fingerprinting) is a technique employed by forensic scientists to assist in the identification of individuals on the basis of their respective DNA profiles. DNA profiles are encrypted sets of numbers that reflect a person's DNA makeup, which can also be used as the person's identifier. DNA profiling should not be confused with full genome sequencing. It is used in, for example, parental testing and rape investigation.

Although 99.9% of human DNA sequences are the same in every person, enough of the DNA is different to distinguish one individual from another. DNA profiling uses repetitive ("repeat") sequences that are highly variable, called variable number tandem repeats (VNTR). VNTRs loci are very similar between closely related humans, but so variable that unrelated individuals are extremely unlikely to have the same VNTRs.

GLOBAL offers the following DNA Testing:

Paternity Testing
Paternity DNA Testing GLOBAL provides DNA paternity testing. We guarantee 100% accurate, confidential results.

DNA paternity testing determines whether a man could be the biological father of a child. We all inherit our DNA (the genetic material) from our biological parents. A DNA paternity test compares a child’s DNA pattern with that of the alleged father to check for evidence of this inheritance—the most definitive proof of a biological relationship.

The result of a DNA paternity test is either an exclusion (the alleged father is not the biological father), or an inclusion (the alleged father is considered the biological father). For a standard paternity test, GLOBAL guarantees at least 99.99% probability of paternity for inclusions or 100% certainty of exclusion.

Family Relationship Testing
GLOBAL provides a variety of Family Relationship DNA tests for use in different situations. Some clients may wish to confirm their biological relationship to an alleged father's family if the potential father is unavailable for a paternity test. Others may need to verify family relationships in an immigration or adoption case.

Maternity Testing
Maternity DNA testing determines whether a woman could be the biological mother of a child. Like a DNA paternity test, it compares a child’s DNA pattern with that of the alleged mother to determine how likely it is that the child has inherited the DNA from the alleged mother.
Maternity test results may be used in the following circumstances:

• To confirm that an adoptee has been reunited with his/her birth mother
• To prove biological relationships in an immigration case.
• To confirm that an embryo conceived through in vitro fertilization was implanted into the correct mother
• To resolve situations in which mothers or hospital staff suspect that a baby mix-up has occurred in the nursery

In a maternity test, the child, alleged mother, and biological father are tested. The father’s participation in the maternity test helps to exclude half of the child’s DNA, leaving the rest for comparison with the alleged mother. If the father is not available, we can perform a fatherless test, which involves additional analysis.

Grandparentage Testing
A grandparentage DNA test determines whether a couple could be the biological grandparents of a child. It is an indirect way to determine family relationships when an alleged father is not available for a paternity test. Grandparentage test results may be used as proof in Social Security benefit and other inheritance claims as well as in some immigration cases.

In this test, the child’s DNA profile is compared with the DNA profiles of the alleged father’s biological parents. Since a child inherits half of his/her DNA from the mother (maternal side) and half from the father (paternal side), the paternal half should match DNA passed down from the alleged grandparents. The mother’s participation is encouraged to strengthen the genetic results.  When the mother and both paternal grandparents are included, the probability can be as high as a paternity test.

Siblingship Testing
A siblingship test is a DNA test conducted to determine if two children share one or both parents (i.e., if they are half or full siblings). It is an indirect way to determine family relationships when an alleged father is not available for a paternity test. Results of a siblingship test may be used as proof in Social Security benefit and other inheritance claims.

A siblingship test starts with the analysis of known relatives:

• Sibling 1 and Sibling 2 do not share the same mother and they want to find out if they share the same biological father—in this situation, a half vs. unrelated siblingship test is performed.
• Sibling 1 and Sibling 2 share the same biological mother but are unsure if they share the same biological father—in this situation, a full vs. half siblingship test is performed.
  

In the test, the siblings’ DNA profiles are compared to see how much of their DNA could have come from a common father. Participation of the mother(s) is encouraged to help exclude the mother’s contribution to the children’s DNA. Siblingship tests could require more analysis, and they could be more costly and take a longer time to complete without the mother’s participation.

Twin Zygosity Testing
A twin Zygosity test is a DNA test that definitively shows whether twins are identical or fraternal.

During OB-GYN visits, the physician might be able to tell whether twins are identical or fraternal through ultrasound examination of the placenta. When the twins are born, pathological examination of the placenta can also be done to determine Zygosity.

However, studies have shown that both methods are not 100% accurate, and scientists recommend DNA testing to determine Zygosity. There are also many cases in which medical records regarding Zygosity have been lost, or doubt may have arisen because of the twins’ physical characteristics as they grow up.

In such cases, only a DNA test will be able to reveal the truth. A twin Zygosity test compares the twins’ DNA profiles to see whether they match—an exact match proves that the twins are identical.

The results of a twin Zygosity test may be used to satisfy personal curiosity as well as to help solve health problems for the twins later down the road. For example, in the event that a twin needs an organ or tissue transplant donor, the identical twin is a perfect choice.

Genetic Reconstruction
In genetic reconstruction, a series of DNA tests are conducted to determine whether or not a child is related to the alleged father’s close relatives. It is an indirect way to determine family relationships when an alleged father is not available for a paternity test. Results of genetic reconstruction may be used as proof in Social Security benefit and other inheritance claims.

In the test, the child’s DNA profile is compared with the DNA profiles of at least two of the alleged father’s close relatives. A close relative may be a full sibling or a biological parent. Each individual’s DNA profile is unique, but close relatives will share a significant portion of their DNA profiles because of the hereditary nature of DNA.

Genetic reconstruction requires complex analytical methods. If only two of the alleged father's close relatives are available to take the test, participation of the child's mother is recommended. If the child's mother is not available, we recommend performing the test with the participation of at least three close relatives of the alleged father.

Maternal Relative (mt DNA) Comparison Test
This test is used to support or disprove a direct maternal connection between 2 or more participants (male or female).

The mtDNA comparison DNA test, also known as a maternal lineage test, can confirm your relationship to long-lost relatives and possible ancestors through the maternal/female line. It can also provide additional information for situations where maternity is in question, but the mother is unavailable for a maternity test–although maternity itself can't be determined, we can determine the child's relationship to a possible maternal relative.

The testing process is simple—the samples are taken using a painless buccal (cheek) swab, and testing is completed in 2–3 weeks. We will use a Chain of Custody collection process where your samples will be taken by a trained professional in a laboratory or clinic.

mtDNA Comparison vs. Ancestry DNA Testing
Unlike ancestry DNA tests, which give an ancient picture of your family and traces your geographical roots back several thousands of years, the comparison mtDNA test provides scientific confirmation of more recent relationships—for example, if you have identified a possible relative from genealogy research and want to confirm your relationship. This mtDNA comparative analysis will tell you whether or not your mtDNA sequences are consistent, or not consistent, with the conclusion that you and the possible relative(s) may be related through a common female ancestor.

mtDNA is Maternally Inherited
Both men and women have mitochondrial DNA (mtDNA); however, only women can pass their mtDNA on to their children. In a mitochondrial DNA comparison test, individuals’ mtDNA sequences are compared to see if they share certain regions of the DNA that indicate they come from the same maternal line.

The mtDNA test compares your mtDNA sequence with the Cambridge Sequence, a reference sequence of mtDNA. While most of the mtDNA sequence does not change from generation to generation, there is a variable region in the mtDNA that does change, with a mutation rate that has been determined by scientists.

When variations are found between your sequence and the reference sequence, these indicate how the human race branched off over the years. Through many generations, your family’s sequence variations stay intact and are passed down through maternal lines.

For example, if a female in Generation One has a specific mtDNA sequence, then all of her descendants (male or female) with a direct maternal connection to her would also have similar markers through many generations, as shown in the above illustration. This means that her sons and daughter would have the same mtDNA sequence, but only her daughter would pass on this sequence.

Paternal Relative (Y-STG) Comparison Test
This test is used to support or disprove a direct paternal connection between 2 or more male participants.

The paternal relative (Y-STR) comparison test, also known as a paternal lineage test, can confirm your relationship to long-lost relatives and paternal ancestors. This DNA test is also often used to provide additional evidence in difficult paternity cases in which the alleged father is not available for testing—indirectly, it can tell whether or not a child is related to the alleged father's brothers and other male relatives who share a common paternal line.

The testing process is simple—the samples are taken using a painless buccal (cheek) swab, and testing is completed in 2–3 weeks. We will use a Chain of Custody collection process where your samples will be taken by a trained professional in a laboratory or clinic.

Y-STR Comparison vs. Ancestry DNA Testing
Unlike ancestry DNA tests, which give an ancient picture of your family and traces your geographical roots back several thousands of years, the Y-STR comparison test provides scientific confirmation of more recent relationships—for example, if you have identified a possible relative from genealogy research and want to confirm your relationship. This Y-STR comparative analysis will tell you whether or not your Y-STRs are consistent, or not consistent, with the conclusion that you and the possible relative(s) may be related through a common male ancestor.

Comparison Testing in Paternity Situations
In a paternity situation where the alleged father is missing, Y-STR analysis cannot distinguish a specific relationship between males who belong to the same paternal line. However, it is useful for excluding males from an alleged biological relationship. For example, if a male child and his alleged uncle (alleged father’s full brother) are tested, their Y-STR profiles must match. If they do not, then the alleged uncle is excluded (not considered a biological uncle) and the alleged father is probably not the biological father.

Y Chromosome Inheritance
The Y-STR comparison DNA test is based on the fact that the Y chromosome is passed from father to son relatively unchanged through many generations. The illustration to the right shows a typical inheritance pattern for the Y chromosome. Because the Y chromosome follows the same father-to-son pattern much like surnames in Western culture, the test has also been referred to as a "Surname Test."

Although the Y chromosome is only found in males, women can also indirectly participate in a Y-STR DNA test if they are interested in determining their paternal relatives. They would need to ask a biological male relative, such as a father, brother, paternal uncle, or paternal grandfather to contribute a sample for comparison testing with her potential paternal relative or ancestor.

In a Y-STR DNA test, specific locations on the Y chromosome are examined to generate a Y-STR profile for each male tested. Males who are related through their fathers will tend to have the same or similar Y-STR profiles, and males who are not related will likely have different Y-STR profiles.

Immigration Testing
GLOBAL is certified by the testing lab for the collection of biological specimens.  Our DNA testing laboratory, Chromosomal Laboratories, Inc., is AABB accredited for relationship DNA testing.

Forensic Testing
GLOBAL offers DNA testing and expert services to legal professionals with forensics needs.  GLOBAL is set apart from other providers in that they have been in the testing administration for drugs and alcohol for 29 years and have a highly experienced staff in the forensics field.  They are a certified collection facility for Chromosomal Laboratories, Inc. of Phoenix, AZ. with its highly experienced forensics DNA experts and stringent laboratory quality control. Chromosomal Laboratories, Inc. has several licensees, certificates, and certifications and are accredited by the AABB (American Association of Blood Banks).  Upon inquiry, we will send complete details regarding qualifications of GLOBAL and Chromosomal Laboratories, Inc.

Ancestry Testing
Curious about your geographic roots? Thanks to the magic of DNA testing, you can discover the paths your ancestors took.