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PubMed This is a summary of 19 peer-reviewed journal articles Updated
Medical Genetics · Osteopoikilosis

Biology & Genetics: The LEMD3 Gene and Related Syndromes

At a Glance

Osteopoikilosis is a benign, inherited condition caused by a mutation in the LEMD3 gene. This mutation removes the natural "brake" on bone-building signals, creating small, dense bone islands. It is a harmless trait that has a 50% chance of being passed to children.

Understanding why “bone islands” form requires looking deep inside your cells at a specific instruction manual called the LEMD3 gene. While the name sounds complex, the biology of osteopoikilosis is actually a story about a missing “brake” in your bone-building system [1][2].

The Role of the LEMD3 Gene

Every cell in your body has a nucleus, and the LEMD3 gene (sometimes called MAN1) provides the instructions for a protein that sits on the inner wall of that nucleus [3][1]. This protein has a very specific job: it acts as a negative regulator, or a “brake,” on two major growth pathways called TGF-beta and BMP (Bone Morphogenetic Protein) [1][2].

In a typical person:

  1. Growth signals (TGF-beta and BMP) tell the body to create new bone [4].
  2. The LEMD3 protein eventually steps in to stop those signals so the bone doesn’t become too dense [1][5].

In someone with osteopoikilosis, one copy of the LEMD3 gene has a mutation (a “loss-of-function” mutation) [2][6]. Because there isn’t enough of the “brake” protein, the bone-building signals stay active longer than they should [2][5]. This leads to the small, circular clusters of extra-dense bone known as bone islands or enostoses [7][8].

Inheriting the Trait

Osteopoikilosis follows an autosomal dominant inheritance pattern [6][8]. This means:

  • Autosomal: The gene is not on a sex chromosome; it affects men and women equally.
  • Dominant: You only need one mutated copy of the gene from one parent to have the condition [9].
  • 50% Chance: If you have the mutation, there is a 50% chance of passing it on to each of your children [9]. Because the condition is harmless, children do not need X-rays or genetic testing just to see if they inherited it.

Related Syndromes: When It’s More Than Just Bone

While most people have “isolated” osteopoikilosis (meaning they only have the bone spots), the LEMD3 mutation can sometimes affect other tissues.

Buschke-Ollendorff Syndrome (BOS)

If a person has both osteopoikilosis and specific skin findings, it is called Buschke-Ollendorff Syndrome [10][11]. The skin lesions are typically connective tissue nevi—painless, small, yellowish or skin-colored bumps that are often found on the torso, arms, or legs [12][13]. Like the bone islands, these skin spots are benign and usually do not require treatment [12].

Melorheostosis

In very rare cases, osteopoikilosis can overlap with a condition called melorheostosis [14][15]. While osteopoikilosis looks like “dots,” melorheostosis looks like “dripping candle wax” on the side of a bone [16][17]. Unlike isolated osteopoikilosis, melorheostosis can be painful and may cause joint stiffness [17][18]. Current research suggests melorheostosis is usually caused by different, non-inherited mutations that occur randomly in specific cells (called somatic mosaicism), though they can occasionally occur together in the same person [14][15].

Why This Matters

Knowing the genetic cause (LEMD3) helps confirm that your “spots” are a result of a minor signaling error during bone development [2]. It provides peace of mind that these dense areas are not aggressive growths, but rather a permanent, stable part of your unique biological blueprint [19].

Common questions in this guide

What causes osteopoikilosis?
Osteopoikilosis is caused by a mutation in the LEMD3 gene. This gene normally produces a protein that acts as a brake on bone-building signals. Without enough of this protein, bone growth pathways stay active longer than they should, forming dense spots called bone islands.
Is osteopoikilosis inherited?
Yes, it follows an autosomal dominant inheritance pattern. This means you only need to inherit one mutated copy of the gene from a parent to have the condition, and there is a 50% chance of passing the trait on to each of your children.
Should my children get genetic testing for osteopoikilosis?
Because isolated osteopoikilosis is completely harmless, doctors generally do not recommend putting children through X-rays or genetic testing just to see if they inherited the trait.
What is Buschke-Ollendorff Syndrome?
Buschke-Ollendorff Syndrome is a condition where a person has both the bone islands of osteopoikilosis and specific skin lesions. These skin spots are painless, yellowish or skin-colored bumps that are harmless and usually do not require treatment.
Can osteopoikilosis cause bone pain or joint stiffness?
Isolated osteopoikilosis is painless. However, if it overlaps with a rare condition called melorheostosis—which appears as a "dripping candle wax" pattern on X-rays—you may experience deep bone pain and joint stiffness.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.Does my diagnosis seem to be isolated, or are there signs of Buschke-Ollendorff Syndrome?
  2. 2.Based on my imaging, is there any evidence of melorheostosis overlap, such as 'dripping candle wax' bone patterns?
  3. 3.Do you recommend genetic testing for the LEMD3 gene for me or my family?

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 (19)
  1. 1

    Structural basis for receptor-regulated SMAD recognition by MAN1.

    Miyazono KI, Ohno Y, Wada H, et al.

    Nucleic acids research 2018; (46(22)):12139-12153 doi:10.1093/nar/gky925.

    PMID: 30321401
  2. 2

    The Buschke-Ollendorff syndrome: a case report of simultaneous osteo-cutaneous malformations in the hand.

    Brodbeck M, Yousif Q, Diener PA, et al.

    BMC research notes 2016; (9()):294 doi:10.1186/s13104-016-2095-2.

    PMID: 27267960
  3. 3

    LEM-Domain-Containing Inner Nuclear Membrane Proteins: Emerging Regulators of Intranuclear Signaling.

    Lee B, Lee H, Shim J

    International journal of molecular sciences 2026; (27(2)) doi:10.3390/ijms27020942.

    PMID: 41596589
  4. 4

    MAN1 Restricts BMP Signaling During Synaptic Growth in Drosophila.

    Laugks U, Hieke M, Wagner N

    Cellular and molecular neurobiology 2017; (37(6)):1077-1093 doi:10.1007/s10571-016-0442-4.

    PMID: 27848060
  5. 5

    KLF4 is a key determinant in the development and progression of cerebral cavernous malformations.

    Cuttano R, Rudini N, Bravi L, et al.

    EMBO molecular medicine 2016; (8(1)):6-24 doi:10.15252/emmm.201505433.

    PMID: 26612856
  6. 6

    Identification of a novel LEMD3 Y871X mutation in a three-generation family with osteopoikilosis and review of the literature.

    Zhang Q, Mo ZH, Dong CS, et al.

    Journal of endocrinological investigation 2016; (39(6)):679-85 doi:10.1007/s40618-015-0419-z.

    PMID: 26694706
  7. 7

    Osteopoikilosis-the incidental finding of a rare bone dysplasia: A case report.

    Rosa-Juana TP, Ana AL, Julia MD, Sara CP

    Clinical case reports 2024; (12(7)):e9191 doi:10.1002/ccr3.9191.

    PMID: 39027358
  8. 8

    A novel LEMD3 pathogenic variant in a son and mother with osteopoikilosis.

    Elmaoğulları S, Yıldız AE, Demir S, et al.

    The Turkish journal of pediatrics 2019; (61(4)):594-598.

    PMID: 31990479
  9. 9

    Familiar osteopoikilosis: Case report with differential diagnosis and review of the literature.

    Gaudio A, Xourafa A, Rapisarda R, et al.

    Clinical case reports 2021; (9(2)):922-926 doi:10.1002/ccr3.3611.

    PMID: 33598273
  10. 10

    Mutation in LEMD3 (Man1) Associated with Osteopoikilosis and Late-Onset Generalized Morphea: A New Buschke-Ollendorf Syndrome Variant.

    Korman B, Wei J, Laumann A, et al.

    Case reports in dermatological medicine 2016; (2016()):2483041 doi:10.1155/2016/2483041.

    PMID: 27382493
  11. 11

    Buschke-Ollendorff syndrome with LEMD3 germline stopgain mutation p.R678* presenting as multiple subcutaneous nodules with mucin deposition.

    Xu Z, Yang C, Xue R

    Journal of cutaneous pathology 2021; (48(1)):77-80 doi:10.1111/cup.13771.

    PMID: 32519343
  12. 12

    Buschke-Ollendorff syndrome in a 6-year-old patient: clinical and histopathological aspects of a rare disease.

    Diotallevi F, Simonetti O, Radi G, et al.

    Acta dermatovenerologica Alpina, Pannonica, et Adriatica 2020; (29(1)):31-33.

    PMID: 32206820
  13. 13

    Elastoma: clinical and histopathological aspects of a rare disease.

    Maciel MG, Enokihara MM, Seize MB, et al.

    Anais brasileiros de dermatologia 2016; (91(5 suppl 1)):39-41 doi:10.1590/abd1806-4841.20164541.

    PMID: 28300889
  14. 14

    Melorheostosis and Osteopoikilosis Clinical and Molecular Description of an Italian Case Series.

    Gnoli M, Staals EL, Campanacci L, et al.

    Calcified tissue international 2019; (105(2)):215-221 doi:10.1007/s00223-019-00565-6.

    PMID: 31129707
  15. 15

    Melorheostosis: Exome sequencing of an associated dermatosis implicates postzygotic mosaicism of mutated KRAS.

    Whyte MP, Griffith M, Trani L, et al.

    Bone 2017; (101()):145-155 doi:10.1016/j.bone.2017.04.010.

    PMID: 28434888
  16. 16

    Melorheostosis: a Rare Sclerosing Bone Dysplasia.

    Kotwal A, Clarke BL

    Current osteoporosis reports 2017; (15(4)):335-342 doi:10.1007/s11914-017-0375-y.

    PMID: 28676968
  17. 17

    Buschke-Ollendorff syndrome presenting with asymptomatic yellowish papules and leg length discrepancy: A case report.

    Hung WK, Shen MH, Chen KY, et al.

    Journal of musculoskeletal & neuronal interactions 2022; (22(2)):292-295.

    PMID: 35642708
  18. 18

    Melorheostosis and Osteopoikilosis: A Review of Clinical Features and Pathogenesis.

    Wordsworth P, Chan M

    Calcified tissue international 2019; (104(5)):530-543 doi:10.1007/s00223-019-00543-y.

    PMID: 30989250
  19. 19

    Osteopoikilosis Demonstrating Multiple Joint Involvement in an Adult Male: An Incidental Radiographic Finding.

    Botwin A, Wasyliw C

    Cureus 2018; (10(9)):e3253 doi:10.7759/cureus.3253.

    PMID: 30430046

This page explains the genetics and biology of osteopoikilosis for educational purposes only. Always consult a genetic counselor or your healthcare provider to discuss your specific diagnosis or family history.

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