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Last reviewed: May 12, 2026 Last updated: May 12, 2026

Written by: Jay Hastings , CEO of PlexusDx

Jay Hastings is the CEO of PlexusDx, a precision health company focused on genetic testing, blood biomarker insights, and personalized wellness recommendations. He has more than 20 years of experience across healthcare innovation, genomics, laboratory operations, healthcare investing, and strategic finance. His work has included scaling healthcare startups, leading CLIA lab integrations, and helping expand consumer access to precision health tools.

Medically reviewed by: Jayden Lee, PharmD, EMBA

Jayden Lee, PharmD, EMBA, is the PlexusDx Medical Science Liaison with a PharmD and MBA specializing in pharmacogenomics and clinical product development, with a proven ability to bridge the gap between genomic research and practical patient outcomes. Dr. Lee has more than 10 years of professional experience in clinical pharmacy, academia, and research.

Molybdenum, the XDH Gene, and How They Affect Purine Metabolism

Molybdenum is an essential trace mineral that helps several enzymes do their jobs. One of these enzymes, xanthine dehydrogenase, is made by the XDH gene and depends on molybdenum to convert purines into uric acid so the body can eliminate them. Variants in the XDH gene can reduce or remove this enzyme’s activity, which may cause xanthine to build up instead of being converted to uric acid. This can sometimes lead to very low blood uric acid levels and an increased risk of forming xanthine kidney stones.

Why this matters

  • Purines are compounds found naturally in your body and in many foods. Proper breakdown prevents buildup of intermediate products like xanthine.
  • When xanthine accumulates it may form crystals that can lead to kidney stones or other urinary tract symptoms.
  • Molybdenum is required for the enzyme to function. Diet, hydration, and genetics together influence risk.

Common signs and when to follow up

  • Many people with one altered copy of XDH (carriers) have no symptoms.
  • People with two altered copies may have very low uric acid and a higher chance of xanthine stones.
  • Consider testing urine and blood uric acid if you have recurrent kidney stones, unexplained low uric acid, or family history of xanthinuria.

Practical Recommendations

PlexusDx provides genetic education only and does not give medical advice. Always discuss test results and changes to diet, supplements, or medical care with your healthcare provider.

Hydration and lifestyle

  • Maintain good hydration: aim for urine that is light yellow most of the day. Increased fluid intake helps dilute urine and reduces stone risk.
  • Avoid prolonged dehydration, especially during exercise or heat exposure.
  • Maintain a healthy body weight and regular physical activity to support overall kidney and metabolic health.

Dietary guidance

  • Moderate intake of high-purine foods: limit organ meats (liver, kidney), certain seafood (anchovies, sardines, mackerel), and very high-purine preparations.
  • Focus on a balanced diet rich in legumes, whole grains, fruits, and vegetables. These foods support overall purine metabolism and kidney health.
  • Limit excessive protein from single sources and consider spreading protein intake across meals.
  • Avoid high-sulfite foods if you are sensitive; molybdenum-dependent enzymes also help break down sulfites.

Supplements and nutrients

  • Do not start molybdenum supplements without medical guidance. Most people get adequate molybdenum from food, and supplementation is rarely necessary.
  • Discuss multivitamins or targeted supplements with your provider if you have restricted diets or malabsorption issues.
  • Maintain adequate dietary calcium and avoid excessive vitamin C doses that may change urinary oxalate — discuss with your clinician if you have a history of stones.

When to test and what to monitor

  • Blood uric acid levels: very low levels could prompt further evaluation for xanthinuria.
  • Urine analysis for xanthine crystals and 24-hour urine collection if kidney stones are recurrent.
  • Kidney imaging if clinically indicated for stones or pain.
  • Genetic counseling if you have two copies of a pathogenic XDH variant, or family members with symptomatic xanthinuria.

Genetic Interpretations

The accordion below explains what each genotype at rs72549369 in the XDH gene typically means. These interpretations are educational only. PlexusDx does not provide medical advice. Review results with your healthcare provider for personalized guidance.

Two effect alleles (AA) — Carrier of mutation related to xanthine oxidase deficiency

If you have the AA genotype for rs72549369, you carry two copies of the effect allele associated with xanthine oxidase deficiency, also called xanthinuria. The XDH gene encodes xanthine dehydrogenase, a molybdenum-dependent enzyme that converts purines into uric acid. With both copies altered, enzyme activity may be reduced or absent.

Potential consequences

  • Xanthine can accumulate in blood and urine instead of being converted to uric acid.
  • Very low blood uric acid levels are possible.
  • Increased risk of xanthine kidney stones and related urinary symptoms.

Suggested actions

  • Discuss these results with your healthcare provider and consider referral to a specialist or genetic counselor.
  • Have blood uric acid measured and consider urine testing for xanthine if clinically indicated.
  • Prioritize hydration and dietary moderation of high-purine foods such as organ meats and certain seafood.
  • Avoid starting molybdenum supplements without clinician input.

PlexusDx does not provide medical advice. Consult your healthcare provider for evaluation, testing, and personalized recommendations.

One effect allele (AG) — Carrier with likely adequate enzyme function

If you have the AG genotype for rs72549369, you carry one copy of the effect allele and one normal copy of XDH. Most carriers have one working gene copy that produces enough xanthine dehydrogenase for normal purine breakdown. Carriers typically do not have symptoms of xanthinuria.

What to watch for

  • Enzyme activity is generally adequate but may be slightly reduced in some carriers.
  • Routine care is usually sufficient; symptomatic issues are uncommon.

Practical tips

  • Stay well-hydrated to support kidney health and reduce stone risk.
  • Consider moderating intake of high-purine foods such as organ meats and certain seafood.
  • Discuss any history of kidney stones or family concerns with your healthcare provider to determine if further testing is needed.

PlexusDx does not provide medical advice. Consult your healthcare provider for testing or if you have symptoms.

No effect alleles (GG) — Typical genotype

If you have the GG genotype for rs72549369, you carry two copies of the non-effect allele. This is the typical genotype and suggests the XDH gene at this location functions normally to produce xanthine dehydrogenase. Purine metabolism at this genetic position is expected to work as intended.

General guidance

  • Maintain normal hydration and a balanced diet rich in legumes, whole grains, fruits, and vegetables.
  • No special genetic follow-up for xanthinuria is typically required unless you have clinical symptoms or family history of kidney stones.
  • Speak with your healthcare provider about routine screening only if you experience urinary symptoms or recurrent stones.

PlexusDx does not provide medical advice. Consult your healthcare provider for any health concerns.

Final notes

Variants in the XDH gene can influence how your body handles purines and the risk of xanthine accumulation. Whether you carry two, one, or no effect alleles, lifestyle measures such as staying hydrated, moderating high-purine foods, and working with your healthcare provider on any testing are practical steps to support kidney and metabolic health. PlexusDx provides educational information only; always consult your healthcare provider for medical advice, diagnosis, or treatment based on your genetic results.

If this genetic variant is present in your PlexusDx results, the following tests and reports are commonly used to explore it further:

🧬 Genetic Tests:

🧪 Blood Tests:

📄 Genetic Report:

Frequently Asked Questions About Molybdenum and XDH rs72549369

What does an XDH gene variant do to purine metabolism?

The XDH gene helps make xanthine dehydrogenase, a molybdenum-dependent enzyme that converts purines into uric acid for elimination. Variants in XDH can reduce or remove enzyme activity, which may cause xanthine to build up instead of being converted to uric acid. This can be associated with very low blood uric acid levels and an increased risk of xanthine kidney stones.

What are the rs72549369 genotype differences (GG, AG, and AA) and their typical risks?

With rs72549369, GG (no effect alleles) typically suggests normal XDH function and no special follow-up unless you have symptoms or recurrent stones. AG (one effect allele) usually means you’re a carrier with likely adequate enzyme function, and most carriers have no symptoms. AA (two effect alleles) is associated with xanthine oxidase deficiency/xanthinuria, where enzyme activity may be reduced or absent—leading to possible very low uric acid and a higher risk of xanthine kidney stones and urinary symptoms.

What should I do if I have recurrent kidney stones or low uric acid with an XDH variant?

Consider follow-up with your healthcare provider for evaluation such as blood uric acid testing and, if clinically indicated, urine testing for xanthine crystals (sometimes including a 24-hour urine collection) and kidney imaging for stones or pain. Practical steps include maintaining good hydration (light yellow urine most of the day) and moderating high-purine foods (e.g., organ meats and certain seafood). Do not start molybdenum supplements without clinician guidance, and review dietary changes and supplement needs with your provider.

What tests can help me learn more about Molybdenum and XDH rs72549369?

The Optimal Diet and Weight Loss Genetic Test delivers over 295 genetic insights related to nutrition response, body composition, metabolism, and fitness. The Diet and Nutrition Genetic Report translates your results into personalized, actionable guidance. Your healthcare provider can also recommend targeted blood tests based on your specific pathway results and health history to complement your genetic insights with current biomarker data.

Medical and Editorial Standards

Medical review process: This article was reviewed for medical accuracy, scientific clarity, evidence alignment, and appropriate discussion of genetics, medications, supplements, biomarkers, and health-related claims.

Sources and evidence: PlexusDx educational content is developed using peer-reviewed research, clinical literature, reputable medical references, and, where applicable, public health or regulatory guidance. References are included at the end of the article when scientific, medical, or health-related claims are discussed.

Commercial transparency: PlexusDx offers genetic testing, blood biomarker testing, personalized supplement recommendations, and related precision wellness services. Product mentions are intended to help readers understand available options and should not be interpreted as medical advice.

Important disclaimer: PlexusDx educational content is for informational purposes only and should not be used as a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making decisions about medications, supplements, genetic testing, lab testing, or health-related care.