What Age is Appropriate for Genetic Testing?

By: Dr. Robyn Murphy, ND

Your genes are the same throughout life, so genetic testing could technically be done from the point of conception; however, this seems somewhat invasive. Joking aside, this question comes up frequently from savvy parents looking to make the best lifestyle and dietary choices for their kids for prevention as well as optimizing their potential.

Some key information is available to parents using genetic testing.

1.  Dietary restrictions

Genetic testing is exceptionally helpful for parents who want to know if their child is at risk for Celiac disease or gluten sensitivity. It is especially helpful if a first-degree relative has Celiac, or another autoimmune disease, such as Type I Diabetes. This increases the chances of developing Celiac. While studies show that the timing of gluten introductions does not change the risk of developing the disease, the amount certainly does. 1 In addition, non-celiac gluten sensitivity may trigger changes in immune response, mood, cognition and gut health if left undetected.2,3,4

Determining whether or not lactose intolerance is present is a simple test that can potentially prevent years of fussy babies. Undigested lactose from dairy can lead to bloating, gas, diarrhea and abdominal discomfort. Genetic testing does not determine if there is a dairy allergy, rather if lactose is able to be digested properly. It is suggested that parents consider separate testing since allergies to dairy are linked to recurrent ear infections.5

2.  Nutrient requirements

Allergies are rampant in today’s school population, leading to numerous food restrictions in kids that may otherwise provide adequate sustenance for proper growth and development. Genetic testing identifies the potential risk for nutrient deficiencies, due to changes in how efficient the body is able to absorb, transport and/or metabolize nutrients. This information can guide parents to incorporate certain foods their kids need more of, lab tests to identify deficiencies and possibly supplementation.

Below are some key vitamins and minerals that are susceptible to genetic changes and deficiencies:

  • Vitamin A – for eye and reproductive health and immunity
  • Vitamin D – important for bone development, mood, cell growth and immune function
  • Vitamin C – in addition to vitamin D, deficiency is linked to gingivitis, infections and bronchial asthma in children
  • Iron – essential for oxygen delivery, development and energy
  • Vitamins B12 and folate – cognitive and neurological development
  • Choline – impacts brain development
  • Essential fatty acids – essential for cellular health, low omega 3 status can impact the development of ADHD, sleep disturbances and asthma in children.

3.  Probiotics and Gut health

The microbiome establishes during the first years of life. During this stage, it is important that babies receive the proper nutrition to help beneficial bacteria establish in order for a healthy digestive and immune system. Breast milk contains sugars known as human milk oligosaccharides (HMOs), which are protective to infants and function as a prebiotic in the establishment of bifidobacteria. 6  Infants born to mothers with the ‘non-secretor’ version of the FUT2 gene, have a delay in Bifidobacterium and Bacteroides establishment and may therefore benefit from the addition of probiotics. 6 Studies show that babies who have less Bifidobacterium early on or lower FUT2 dependent HMO are more likely to develop ADHD or allergies, respectively.7,

4.  Behaviour and Development

Behavioural development during childhood is a complex topic, since a child’s behaviour is shaped by numerous interrelated factors; however, genetics may uncover potential predispositions that warrant close observation or early intervention. Certain versions of the COMT gene can influence dopamine levels in the frontal area of the brain, important for focus and various executive functions. Studies show this gene may play a pivotal role in the development of ADHD, severity of autism, depression and PTSD.9,10,11 While many lifestyle genetic tests do not report directly on these topics, understanding if a child is ‘sensitive’ to stressful environments as reported with the COMT gene may prove beneficial in child rearing strategies and further investigation.

5.  Exercise predilection

Is your child the next NBA superstar? While genetic testing isn’t quite at this level, genetic insights into physical fitness reveal what sports children may naturally excel at. Variations in the actin gene, ACTN3, responsible for fast-twitch muscle fibers modifies how the muscle functions during exercise through structural, metabolic or signaling changes.12 Those with the “R” version fair better in power sports and is more common in elite sprint athletes.13 While differences in the ACE gene influence cardiorespiratory efficiency and tolerance towards endurance activities.14

Overall, the key to making the decision of when to introduce genetic testing to children depends on what information may be helpful as outlined above. Lifestyle genetic tests are not all encompassing, predicting all possible outcomes of health. It is important to consider if they are at an age where there are able to follow lifestyle or dietary strategies, what is their level of maturity and motivation, and if the actionable recommendations are applicable. This may be a fun step to take as a family, learn each other’s similarities and differences while encouraging specific and lasting lifestyle habits that ultimately optimize the chances for a healthy life.


  1. Lionetti E, Castellaneta S, Francavilla R, et al. Introduction of Gluten, HLA Status, and the Risk of Celiac Disease in Children. N Engl J Med. 2014;371(14):1295-1303. doi:10.1056/NEJMoa1400697
  2. Sapone A, Lammers KM, Casolaro V, et al. Divergence of gut permeability and mucosal immune gene expression in two gluten-associated conditions: celiac disease and gluten sensitivity. BMC Med. 2011;9:23. doi:10.1186/1741-7015-9-23
  3. Casella G, Pozzi R, Cigognetti M, et al. Mood disorders and non-celiac gluten sensitivity. Minerva Gastroenterol Dietol. 2017;63(1):32-37. doi:10.23736/S1121-421X.16.02325-4
  4. A Daulatzai M. Non-celiac gluten sensitivity triggers gut dysbiosis, neuroinflammation, gut-brain axis dysfunction, and vulnerability for dementia. CNS Neurol Disord-Drug Targets Former Curr Drug Targets-CNS Neurol Disord. 2015;14(1):110–131.
  5. Juntti H, Tikkanen S, Kokkonen J, Alho OP, Niinimäki A. Cow’s milk allergy is associated with recurrent otitis media during childhood. Acta Otolaryngol (Stockh). 1999;119(8):867-873. doi:10.1080/00016489950180199
  6. Lewis ZT, Totten SM, Smilowitz JT, et al. Maternal fucosyltransferase 2 status affects the gut bifidobacterial communities of breastfed infants. Microbiome. 2015;3. doi:10.1186/s40168-015-0071-z
  7. Pärtty A, Kalliomäki M, Wacklin P, Salminen S, Isolauri E. A possible link between early probiotic intervention and the risk of neuropsychiatric disorders later in childhood: a randomized trial. Pediatr Res. 2015;77(6):823-828. doi:10.1038/pr.2015.51
  8. Sprenger N, Odenwald H, Kukkonen AK, Kuitunen M, Savilahti E, Kunz C. FUT2-dependent breast milk oligosaccharides and allergy at 2 and 5 years of age in infants with high hereditary allergy risk. Eur J Nutr. 2017;56(3):1293-1301. doi:10.1007/s00394-016-1180-6
  9. Jung M, Mizuno Y, Fujisawa TX, et al. The Effects of COMT Polymorphism on Cortical Thickness and Surface Area Abnormalities in Children with ADHD. Cereb Cortex N Y N 1991. December 2018. doi:10.1093/cercor/bhy269
  10. Esmaiel NN, Ashaat EA, Mosaad R, et al. The potential impact of COMT gene variants on dopamine regulation and phenotypic traits of ASD patients. Behav Brain Res. 2019;378:112272. doi:10.1016/j.bbr.2019.112272
  11. Danzi BA, La Greca AM. Genetic pathways to posttraumatic stress disorder and depression in children: Investigation of catechol-O-methyltransferase (COMT) Val158Met using different PTSD diagnostic models. J Psychiatr Res. 2018;102:81-86. doi:10.1016/j.jpsychires.2018.03.014
  12. Del Coso J, Hiam D, Houweling P, Pérez LM, Eynon N, Lucía A. More than a “speed gene”: ACTN3 R577X genotype, trainability, muscle damage, and the risk for injuries. Eur J Appl Physiol. 2019;119(1):49-60. doi:10.1007/s00421-018-4010-0
  13. Yang N, MacArthur DG, Gulbin JP, et al. ACTN3 Genotype Is Associated with Human Elite Athletic Performance. Am J Hum Genet. 2003;73(3):627-631.
  14. Peplonska B, Adamczyk JG, Siewierski M, et al. Genetic variants associated with physical and mental characteristics of the elite athletes in the Polish population. Scand J Med Sci Sports. 2017;27(8):788-800. doi:10.1111/sms.12687

About The Author

Dr. Robyn Murphy is the Clinical Research Advisor for AOR and a practicing naturopathic doctor, public speaker and researcher. Immensely passionate about educating both healthcare professionals and the public about advances in genetics and integrative medicine, Dr. Murphy strives to empower individuals with the proper tools and information to significantly change their health. As Scientific Advisor for DNA Labs, Dr. Murphy is the co-developer of lifestyle genetic testing with several published articles in medical journals. She is the past Associate Medical Director of a lifestyle genetics company and co-founder of The IBS Academy. Dr. Murphy holds a Bachelor of Science from the University of Alberta and Doctor of Naturopathic Medicine from CCNM, with advanced training and certifications in functional gastroenterology, hormone therapy (BHRT), biological medicine and advanced medical herbalism.

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