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.

LIG4 and Male Fertility: What Your Genotype Means for Sperm Health

DNA ligase IV, encoded by the LIG4 gene, helps repair DNA double strand breaks that occur during sperm development. When this repair process is less efficient, sperm can end up with higher DNA damage, lower counts, or reduced motility, and that can increase the risk of infertility. Your rs1805388 genotype can influence how well LIG4 performs.

How to read this report

This article explains how different rs1805388 genotypes may affect sperm DNA repair and fertility risk, and gives practical, evidence-informed steps you can take to support sperm health. PlexusDx does not provide medical advice. Always discuss genetic results and health decisions with your healthcare provider.

Genetic interpretations

AA genotype (two effect alleles)

Carrying two copies of the A allele at rs1805388 is associated with reduced DNA ligase IV activity. This may lead to less efficient repair of DNA breaks during spermatogenesis and a higher chance of sperm DNA damage, lower sperm count, and reduced motility compared with typical function.

What you can do

  • Prioritize an antioxidant rich diet: berries, leafy greens, cruciferous vegetables, nuts, and colorful fruits to help reduce oxidative damage to sperm DNA.
  • Consider supplements that support sperm health: N-Acetyl Cysteine 600 to 1200 mg/day, Vitamin C 500 mg or more/day, CoQ10 100 to 200 mg/day, L-carnitine 1 to 2 g/day, and zinc 15 to 30 mg/day. Discuss doses with your clinician before starting.
  • Avoid testicular heat exposure: no hot tubs or saunas and avoid prolonged laptop-on-lap use.
  • Stop smoking, limit alcohol, and reduce exposure to environmental toxins and pesticides.
  • Maintain healthy weight, manage stress, prioritize 7 to 9 hours sleep per night, and engage in moderate regular exercise.
  • If fertility is a concern, consider semen analysis and sperm DNA fragmentation testing; consult a reproductive specialist as needed.
AG genotype (one effect allele)

Carrying one A allele may modestly reduce DNA ligase IV function during sperm development. This can slightly increase the likelihood of sperm DNA damage, lower count, or reduced motility compared with people who do not carry the effect allele, though many carriers have normal fertility.

What you can do

  • Adopt an antioxidant first diet: include berries, leafy greens, cruciferous vegetables, nuts, legumes, and whole grains to support cellular repair.
  • Supplements that may help: N-Acetyl Cysteine, Vitamin C, CoQ10, L-carnitine, and zinc. Speak with your healthcare provider about appropriate dosing and interactions.
  • Reduce heat and toxin exposures, avoid tobacco, and limit excessive alcohol.
  • Optimize lifestyle: healthy weight, stress reduction, consistent sleep, and moderate activity support hormone balance and sperm quality.
  • If you are planning a pregnancy or have concerns, a semen analysis can give a baseline and guide next steps with your clinician.
GG genotype (no effect alleles)

With two copies of the G allele, LIG4 function is expected to be typical. Your risk of infertility related to this specific variant is not elevated. Normal DNA repair activity supports standard spermatogenesis and sperm DNA integrity.

What you can do

  • Continue to support sperm health through an antioxidant rich diet: berries, leafy greens, nuts, cruciferous vegetables, and omega 3 rich foods such as fatty fish or algae sources.
  • Maintain healthy lifestyle habits: avoid heat to the testes, minimize toxin exposures, avoid smoking, limit alcohol, manage stress, keep a healthy weight, get adequate sleep, and exercise regularly.
  • Consider periodic semen analysis if you have reproductive plans or risk factors such as prior infections, undescended testes, or occupational exposures.

Dietary and supplement guidance

Nutrition plays a key role in protecting sperm DNA and supporting overall sperm quality. Focus on whole foods that provide antioxidants, healthy fats, and micronutrients that are particularly important for sperm function.

  • Antioxidant rich foods: berries, cherries, citrus, dark leafy greens, tomatoes, bell peppers, and cruciferous vegetables.
  • Healthy fats: fatty fish, walnuts, chia or flax seeds, and olive oil to support membrane health and hormone production.
  • Micronutrient sources: oysters, lean meats, beans, seeds, and fortified cereals for zinc, selenium, folate, and B vitamins.
  • Hydration: adequate fluid intake supports semen volume and concentration.

Supplements sometimes used to support sperm health include

  • N-Acetyl Cysteine 600 to 1200 mg/day
  • Vitamin C 500 mg or more/day
  • Coenzyme Q10 100 to 200 mg/day
  • L-carnitine 1 to 2 g/day
  • Zinc 15 to 30 mg/day

Discuss supplements with your healthcare provider to confirm suitability, dosing, and interactions with medications or medical conditions.

Lifestyle actions that support sperm DNA and fertility

  • Avoid heat exposure to the testes: brief periods at elevated temperature can impair sperm production for several months.
  • Stop smoking and reduce alcohol intake: both are associated with worse sperm parameters and increased DNA damage.
  • Limit exposure to environmental toxins: reduce contact with pesticides, solvents, and heavy metals relevant to your occupation or home environment.
  • Maintain a healthy weight: both underweight and overweight can affect hormone balance and sperm quality.
  • Manage stress and prioritize sleep: chronic stress and poor sleep can disrupt hormones that regulate sperm production.
  • Exercise moderately: regular physical activity supports hormonal health; avoid excessive endurance training that may impair fertility.

When to seek testing or specialist care

  • After 12 months of trying to conceive without success, or after 6 months if you are over age 35, consult your healthcare provider for evaluation.
  • Consider a semen analysis to assess count, motility, morphology, and volume.
  • If semen parameters are abnormal or if you have recurrent pregnancy loss with a partner, discuss sperm DNA fragmentation testing and referral to a reproductive specialist or urologist.
  • If you have known exposures, prior chemotherapy, a history of testicular injury, undescended testes, or genetic concerns, raise these early with your clinician.

Bottom line

Variants in LIG4 can influence how effectively sperm DNA is repaired. If you carry one or two copies of the effect allele at rs1805388, you may have a higher risk of sperm DNA damage and related fertility issues, but many lifestyle and nutritional steps can help protect sperm health. If your genotype does not carry the effect allele, standard fertility protective practices remain important.

Important: PlexusDx does not provide medical advice. This information is educational only. Discuss your genetic results, supplements, tests, and treatment options with your healthcare provider to determine the best plan for your health and fertility goals.

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 Infertility and LIG4 rs1805388

What does the LIG4 rs1805388 genotype mean for male fertility?

LIG4 (DNA ligase IV) helps repair DNA double-strand breaks during sperm development. Your rs1805388 genotype can influence how efficiently this repair happens. If repair is less efficient, sperm may have higher DNA damage, which can be linked to lower sperm count and/or reduced motility and an increased risk of infertility.

How do AA, AG, and GG rs1805388 genotypes differ in sperm DNA repair risk?

AA (two A alleles) is associated with reduced LIG4 activity, which may increase sperm DNA damage and reduce sperm count and motility versus typical function. AG (one A allele) may modestly reduce LIG4 function and slightly increase the likelihood of DNA damage or weaker sperm parameters, though many carriers have normal fertility. GG (no effect alleles) is expected to have typical LIG4 function and is not associated with elevated infertility risk from this variant.

What fertility-support steps are recommended if I carry the rs1805388 effect allele?

Focus on protecting sperm DNA with an antioxidant-rich diet (berries, leafy greens, cruciferous vegetables, nuts, and colorful fruits), and consider discussing targeted supplements with your clinician—commonly N-acetyl cysteine (600–1200 mg/day), vitamin C (500 mg+), CoQ10 (100–200 mg/day), L-carnitine (1–2 g/day), and zinc (15–30 mg/day). Also avoid testicular heat (no hot tubs/saunas; minimize laptop-on-lap), stop smoking, limit alcohol, reduce toxin exposure, maintain a healthy weight, manage stress, prioritize 7–9 hours of sleep, and exercise moderately. If trying to conceive without success, consider semen analysis and, when appropriate, sperm DNA fragmentation testing with a reproductive specialist.

What tests can help me learn more about Infertility and LIG4 rs1805388?

The Hormone, Thyroid, and Reproductive Health Genetic Test delivers over 85 personalized genetic insights through a comprehensive Hormone & Fertility Genetic Report, explaining inherited tendencies related to hormonal balance, reproductive function, and endocrine signaling. The Mens Hormone and Fertility Health 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.