Chapter 1: The Rise of Direct-to-Consumer Genetic Testing

Direct-to-consumer genetic testing has become increasingly accessible and affordable. While many services focus on ancestry analysis, others provide insights into lifestyle and health-related information. This approach holds the promise of empowering individuals to make informed choices regarding their health risks and enabling healthcare providers to tailor treatment plans more precisely. This concept embodies the essence of precision medicine—personalizing therapies based on a person's unique genetic profile.

However, the potential for misunderstanding these reports is significant. Many of these genetic tests may lack critical information. Sometimes, this is due to the absence of knowledge regarding all genetic variations linked to diseases or drug responses. Other times, relevant data might exist in medical literature but is not included in consumer reports. Both situations can have serious health implications if decisions are made based on incomplete information.

Consider the example of Favism, a genetic disorder caused by mutations in the gene responsible for producing the enzyme glucose-6-phosphate dehydrogenase (G6PD). Deficiencies in this enzyme lead to hemolytic anemia, a condition where red blood cells burst, impairing oxygen transport in the body.

The G6PD gene has numerous variants categorized into five classes based on their impact on enzyme function. Individuals with class 1 variants exhibit the lowest enzyme activity, resulting in chronic anemia, while those with class 2 variants also have a deficiency. Individuals with classes 3 and 4 maintain higher enzyme activity but still less than those without variants. Notably, only individuals with class 1 variants exhibit symptoms, while others may remain asymptomatic, even though some variants offer protection against malaria.

Even those with G6PD deficiency, regardless of class, can face life-threatening crises after consuming certain foods like fava beans or taking specific medications. Alarmingly, screening for G6PD deficiency is not a standard practice for all newborns in the United States.

Given the availability of this genetic information, consumer genetic testing companies could incorporate G6PD deficiency data into their health reports. For instance, 23andMe provides insights into G6PD deficiency risks. However, these reports may not encompass all relevant information.

A case illustrates this concern: a young man with an Ashkenazi Jewish mother and a Northern European father had his wisdom teeth extracted before college and was prescribed antibiotics. After experiencing blood in his urine, a doctor switched his medication to Bactrim, mistakenly believing it would treat a urinary tract infection. His condition worsened, leading to hospitalization with dangerously low oxygen levels.

Despite extensive testing, the medical team initially overlooked the possibility of medication-induced hemolytic anemia due to G6PD deficiency. The situation escalated, necessitating multiple blood transfusions. Meanwhile, the young man's mother, a scientist, began researching hemolytic anemia causes and stumbled upon the connection to Favism.

The G6PD gene, located on the X chromosome, meant that the mother could pass a variant to her son. She had previously utilized 23andMe for her genetic testing and found her health report indicated no variants. However, she was aware that multiple variants could lead to G6PD deficiency.

After further investigation, she discovered that she carried a variant causing class 2 G6PD deficiency. This variant altered the G6PD enzyme's structure, explaining her son's medical crisis, which was triggered by the antibiotic.

Chapter 2: The Importance of Understanding Genetic Reports

While 23andMe's report indicated no variant, a deeper understanding of genetic testing revealed the existence of variants linked to G6PD deficiency. If the young man had relied solely on the health report, he might have been unaware of the need to avoid specific medications, including the one that precipitated his medical emergency. This underscores the necessity of comprehending which genetic variants are assessed in reports.

The limitations of genetic testing services can have serious ramifications. For instance, 23andMe only evaluates specific variants prevalent in certain populations, neglecting those common among other ancestries. This information is outlined on their website, yet the raw genetic data contains insights into other variants that may be more difficult to access.

By providing SNP data, 23andMe empowers families to identify their specific G6PD deficiency variants, enabling them to avoid medications and dietary choices that could trigger dangerous reactions. Surprisingly, the medical professionals consulted in this case were unaware of the genetic information available through consumer testing.

If you've received DNA testing or health reports, it's crucial to recognize the potential dangers of misinterpretation. Many individuals lack the expertise to navigate the raw data, leading to misunderstandings about health risks. Understanding the nuances of genetic testing can empower patients and healthcare providers alike.

Healthcare professionals should consider inquiring whether patients have undergone consumer genetic testing. Referrals to genetic counselors can help patients decode genetic risk reports and unearth vital information not readily available in standard reports.

The first video, "DNA Testing: The Promise And The Peril," delves into the complexities and implications of consumer genetic testing, providing an insightful overview of the topic.

The second video, "The Promise and Peril of Artificial Intelligence," explores the role of AI in genetic testing, shedding light on the intersection of technology and healthcare.