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PubMed This is a summary of 15 peer-reviewed journal articles Updated
Nephrology

Symptoms and Signs to Watch For

At a Glance

Hereditary xanthinuria is often a silent condition, but its main symptoms include invisible xanthine kidney stones that cause flank pain and blood in the urine. Strenuous exercise can trigger acute kidney injury, making proper hydration essential.

Hereditary xanthinuria is often called a ‘silent’ condition because many people do not experience symptoms for years [1]. However, when symptoms do occur, they are typically related to the buildup of xanthine in the kidneys or, more rarely, in the muscles. Understanding these signs can help you identify potential complications early.

The Challenge of ‘Invisible’ Stones

The most common symptom of hereditary xanthinuria is the formation of xanthine stones (urolithiasis) [2]. These stones form because your body cannot break down xanthine into a more soluble form, causing it to crystallize in the urinary tract [3][4].

  • Radiolucent Nature: Unlike many other kidney stones, xanthine stones are often radiolucent, meaning they are essentially invisible on standard X-rays [5]. Doctors usually need an ultrasound or a CT scan to detect them [5][6].
  • Typical Stone Symptoms: If a stone moves or causes a blockage, you may experience:
    • Flank pain: Sharp, severe pain in your back or side, just below the ribs.
    • Hematuria: Blood in the urine, which may look pink, red, or tea-colored [7].
    • Frequent or painful urination: A persistent urge to go or a burning sensation.

Exercise-Induced Acute Kidney Injury (EIAKI)

One of the more serious ways xanthinuria can present is through Exercise-Induced Acute Kidney Injury (EIAKI) [3]. This occurs when intense physical activity causes a sudden, massive surge of xanthine to be filtered through the kidneys [8].

The high concentration of xanthine can suddenly clog the tiny tubes in the kidneys with crystals, leading to temporary kidney failure [9].

  • Signs to Watch For: Following strenuous exercise, you may notice a significant decrease in urine output, nausea, or a sudden, dull ache in the kidney area [10][3].
  • Importance of Hydration: This risk is significantly higher if you are dehydrated during exercise, as there is less fluid to keep the xanthine dissolved [11].

Rare Extra-Renal Symptoms

While the kidneys are the primary concern, some patients experience symptoms in other parts of the body due to xanthine crystal deposits.

  • Myopathy (Muscle Issues): In rare cases, xanthine crystals can deposit directly into muscle tissue, causing myopathy (muscle disease) [3][12]. This can manifest as persistent muscle pain, stiffness, or weakness, particularly after physical exertion [13].
  • Joint Pain: Although much less common than gout (which is caused by uric acid crystals), some patients have reported joint discomfort or arthralgic symptoms if xanthine crystals accumulate in the joints [13].

Are Symptoms Different Between Types?

Currently, researchers have found that Type I and Type II hereditary xanthinuria appear nearly identical in terms of physical symptoms [14][3]. Both types carry the same risks for kidney stones and exercise-related kidney issues [2]. The primary difference lies in how your body processes certain medications, making genetic testing important for long-term safety even if your symptoms are mild [15].

Common questions in this guide

Can standard X-rays detect xanthine kidney stones?
No, xanthine kidney stones are usually radiolucent, meaning they are virtually invisible on standard X-rays. Doctors typically need to use an ultrasound or a CT scan to locate them.
What is exercise-induced acute kidney injury in xanthinuria?
Intense physical activity can cause a sudden surge of xanthine to filter through the kidneys. This high concentration can clog the kidney tubes with crystals, leading to temporary kidney failure, especially if you are dehydrated.
Can hereditary xanthinuria cause muscle pain?
Yes, in rare cases, xanthine crystals can deposit directly into muscle tissue. This causes a condition called myopathy, leading to persistent muscle pain, stiffness, or weakness, particularly after physical exertion.
Are the symptoms different for Type I and Type II xanthinuria?
Type I and Type II hereditary xanthinuria have identical physical symptoms, including the same risks for kidney stones and exercise-related kidney issues. The main difference is how your body processes certain medications, which is why genetic testing is important.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.Since xanthine stones may not show up on a standard X-ray, can we schedule an ultrasound or CT scan to check for them?
  2. 2.Is my history of muscle pain related to my xanthinuria, and should we test for muscle enzyme levels?
  3. 3.How can I safely exercise without increasing my risk for acute kidney injury?
  4. 4.What specific signs of kidney distress should I look for after I've been physically active?
  5. 5.If I need a procedure for a stone, does the fact that it is a xanthine stone change the treatment approach?

Questions For You

Tap a prompt to share your answer — we'll use it plus this page's context to start a tailored conversation.

References

References (15)
  1. 1

    Identification of a new mutation in the human xanthine dehydrogenase responsible for xanthinuria type I.

    Collazo Abal C, Romero Santos S, González Mao C, et al.

    Advances in laboratory medicine 2021; (2(4)):567-574 doi:10.1515/almed-2021-0018.

    PMID: 37360896
  2. 2

    Classical Xanthinuria in Nine Israeli Families and Two Isolated Cases from Germany: Molecular, Biochemical and Population Genetics Aspects.

    Peretz H, Lagziel A, Bittner F, et al.

    Biomedicines 2021; (9(7)) doi:10.3390/biomedicines9070788.

    PMID: 34356852
  3. 3

    A case of xanthinuria type I with a novel mutation in xanthine dehydrogenase.

    Iguchi A, Sato T, Yamazaki M, et al.

    CEN case reports 2016; (5(2)):158-162 doi:10.1007/s13730-016-0216-3.

    PMID: 28508967
  4. 4

    XDH-1 inactivation causes xanthine stone formation in Caenorhabditis elegans which is inhibited by SULP-4-mediated anion exchange in the excretory cell.

    Snoozy J, Bhattacharya S, Johnson B, et al.

    PLoS biology 2025; (23(9)):e3003410 doi:10.1371/journal.pbio.3003410.

    PMID: 40991662
  5. 5

    CT, US and MRI of xanthine urinary stones: in-vitro and in-vivo analyses.

    Shamir SB, Peng Q, Schoenfeld AH, et al.

    BMC urology 2020; (20(1)):157 doi:10.1186/s12894-020-00736-w.

    PMID: 33046039
  6. 6

    Low-Dose Characterization of Kidney Stones Using Spectral Detector Computed Tomography: An Ex Vivo Study.

    Große Hokamp N, Salem J, Hesse A, et al.

    Investigative radiology 2018; (53(8)):457-462 doi:10.1097/RLI.0000000000000468.

    PMID: 29596080
  7. 7

    [Analysis of a family with hypouricemia due to type Ⅰ xanthinuria].

    Wang XY, Wang YJ, Zhou YK

    Zhonghua yi xue za zhi 2024; (104(43)):3985-3988 doi:10.3760/cma.j.cn112137-20240713-01598.

    PMID: 39533690
  8. 8

    Genetic Basis of the Epidemiological Features and Clinical Significance of Renal Hypouricemia.

    Hakoda M, Ichida K

    Biomedicines 2022; (10(7)) doi:10.3390/biomedicines10071696.

    PMID: 35885001
  9. 9

    Xanthine Oxidoreductase Inhibitors Suppress the Onset of Exercise-Induced AKI in High HPRT Activity Urat1-Uox Double Knockout Mice.

    Hosoya T, Uchida S, Shibata S, et al.

    Journal of the American Society of Nephrology : JASN 2022; (33(2)):326-341 doi:10.1681/ASN.2021050616.

    PMID: 34799437
  10. 10

    Unmasking the silent culprit: recurrent exercise-induced acute kidney injury in a Chinese adolescent with renal hypouricemia.

    Gao Y, Xu L, Wei M, et al.

    Renal failure 2024; (46(2)):2373271 doi:10.1080/0886022X.2024.2373271.

    PMID: 39107999
  11. 11

    A frameshift mutation in MOCOS is associated with familial renal syndrome (xanthinuria) in Tyrolean Grey cattle.

    Murgiano L, Jagannathan V, Piffer C, et al.

    BMC veterinary research 2016; (12(1)):276 doi:10.1186/s12917-016-0904-4.

    PMID: 27919260
  12. 12

    [Long-standing myalgia and hypouricemia in a young woman : Case report and review of the literature].

    Venyte R, Schuster-Amft C, Behrendt F, et al.

    Zeitschrift fur Rheumatologie 2025; (84(9)):746-751 doi:10.1007/s00393-025-01689-x.

    PMID: 40810925
  13. 13

    Fortuitous Discovery of Hereditary Xanthinuria.

    Biaz A, Tazi S, Bouhsain S, et al.

    Clinical laboratory 2020; (66(10)) doi:10.7754/Clin.Lab.2020.200253.

    PMID: 33073950
  14. 14

    Urolithiasis due to Hereditary Xanthinuria Type II: A Long-term Follow-up report.

    Kubihal S, Goyal A, Singla R, Khadgawat R

    Indian pediatrics 2020; (57(5)):468-469.

    PMID: 32444521
  15. 15

    Clinical and genetic analysis of MOCOS gene-related hypouricemia.

    Peng H, Tu P, Ma Q, et al.

    Frontiers in genetics 2025; (16()):1636032 doi:10.3389/fgene.2025.1636032.

    PMID: 41164817

This page explains hereditary xanthinuria symptoms for educational purposes only. It does not replace professional medical advice. Always consult your nephrologist or primary care doctor if you experience kidney pain, blood in your urine, or unusual muscle symptoms.

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