Which of the examples of genetic testing below are prognostic tests? Which are diagnostic?

An adult diagnosed with Asperger syndrome (AS) has a genetic test that reveals a SNP in the GABRB3 gene that is significantly more common in people with AS than the general population.

Verified step by step guidance

1. Understand the difference between prognostic and diagnostic tests: Diagnostic tests are used to confirm or rule out a known or suspected genetic disorder in a symptomatic individual, while prognostic tests provide information about the likely course or outcome of a disease.
2. Identify the purpose of the genetic test in the given example: The test reveals a SNP in the GABRB3 gene that is more common in people with AS than in the general population.
3. Determine if the test is used to confirm a diagnosis or predict the course of the condition: Since the individual is already diagnosed with Asperger syndrome, the test is not used to confirm the diagnosis.
4. Consider whether the test provides information about the progression or outcome of the condition: The test identifies a genetic variant associated with AS but does not provide information about the progression or outcome of the condition.
5. Conclude whether the test is prognostic or diagnostic: Since the test does not confirm the diagnosis or predict the course of the condition, it is not a diagnostic or prognostic test. It may be more related to research or understanding genetic associations.

Key Concepts

Prognostic vs. Diagnostic Testing

Prognostic tests are designed to predict the likelihood of developing a disease or the likely course of an existing disease, while diagnostic tests are used to confirm or rule out a specific condition. Understanding the distinction is crucial for interpreting genetic test results, as it informs whether the test is assessing risk or confirming a diagnosis.

Single Nucleotide Polymorphism (SNP)

A Single Nucleotide Polymorphism (SNP) is a variation at a single position in a DNA sequence among individuals. SNPs can be associated with various traits or diseases, making them important in genetic testing. In the context of the question, the SNP in the GABRB3 gene is linked to Asperger syndrome, highlighting its relevance in understanding genetic predispositions.

GABRB3 Gene and Asperger Syndrome

The GABRB3 gene encodes a subunit of the GABA receptor, which is involved in inhibitory neurotransmission in the brain. Variations in this gene have been studied for their potential association with neurodevelopmental disorders, including Asperger syndrome. Recognizing the role of specific genes helps in interpreting the implications of genetic test results in relation to behavioral and cognitive traits.