Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Review Article
  • Published:

A genomic view of mosaicism and human disease

Key Points

  • Mosaicism refers to the presence of genetically distinct cells within an organism that result from postzygotic mutational events.

  • There are several different types of mosaicism at the organismal level that are categorized by the tissue distribution of the variant cells, including germline mosaicism and somatic mosaicism.

  • Many different molecular types of genetic lesions — from single-nucleotide changes to large-scale chromosomal alterations — can be present in a mosaic form.

  • Mosaicism can be generated not only by mutations resulting in variant genotypes but also by the reversion or rescue of abnormal genotypes.

  • Mosaicism can lead to a diverse range of phenotypes, from overt to occult. It can also allow the clinical expression of mutations that would otherwise be lethal in the non-mosaic state, thus providing a broader assessment of genotype–phenotype correlations than do germline-inherited disorders.

  • Modern genomic technologies have allowed the considerable frequency of mosaicism in humans to be increasingly recognized. For example, the frequency of chromosome aberrations in the early embryo has now been estimated as close to 70%.

  • The complexity of the genetic causes and phenotypic consequences of mosaicism pose challenging dilemmas for the diagnosis, prognosis and mechanistic understanding of mosaic diseases in affected individuals.

Abstract

Genomic technologies, including next-generation sequencing (NGS) and single-nucleotide polymorphism (SNP) microarrays, have provided unprecedented opportunities to assess genomic variation among, and increasingly within, individuals. It has long been known that cancer is a mosaic genetic disorder, but mosaicism is now apparent in a diverse range of other clinical disorders, as indicated by their tissue distributions and inheritance patterns. Recent technical advances have uncovered the causative mosaic variant underlying many of these conditions and have provided insight into the pervasiveness of mosaicism in normal individuals. Here, we discuss the clinical and molecular classes of mosaicism, their detection and the biological insights gained from these studies.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Types of mosaicism and patterns of cutaneous mosaicism.
Figure 2: Detection of mosaicism.
Figure 3: Mosaicism for isochromosome 12p in two patients with Pallister–Killian syndrome.
Figure 4: Mechanisms of whole-chromosome uniparental disomy.
Figure 5: Segmental uniparental disomy for 11p in two tissues from one patient.

Similar content being viewed by others

References

  1. Strachan, T. & Read, A. P. Human Molecular Genetics (Garland Science, 2011).

    Google Scholar 

  2. Veltman, J. A. & Brunner, H. G. De novo mutations in human genetic disease. Nature Rev. Genet. 13, 565–575 (2012).

    Article  CAS  PubMed  Google Scholar 

  3. Carlson, B. M. Human Embryology and Developmental Biology (Elsevier/Saunders, 2013).

    Google Scholar 

  4. Tjio, J. H. & Nichols, W. W. History and present status of human chromosome studies. In Vitro Cell Dev. Biol. 21, 305–313 (1985).

    Article  CAS  PubMed  Google Scholar 

  5. Antonarakis, S. E., Phillips, J. A. & Kazazian, H. H. Jr. Genetic diseases: diagnosis by restriction endonuclease analysis. J. Pediatr. 100, 845–856 (1982).

    Article  CAS  PubMed  Google Scholar 

  6. Boehm, J. S. & Hahn, W. C. Towards systematic functional characterization of cancer genomes. Nature Rev. Genet. 12, 487–498 (2011).

    Article  CAS  PubMed  Google Scholar 

  7. Gordon, D. J., Resio, B. & Pellman, D. Causes and consequences of aneuploidy in cancer. Nature Rev. Genet. 13, 189–203 (2012).

    Article  CAS  PubMed  Google Scholar 

  8. Crowe, F. W., Schull, W. J. & Neel, J. V. A Clinical, Pathological and Genetic Study of Multiple Neurofibromatosis (Charles C. Thomas, 1956).

    Google Scholar 

  9. Happle, R. Mosaicism in human skin. Understanding the patterns and mechanisms. Arch. Dermatol. 129, 1460–1470 (1993). This paper summarizes the data for a number of mosaic dermatological disorders and lays out the hypothesis for lethal genes manifesting as mosaic disorders.

    Article  CAS  PubMed  Google Scholar 

  10. Callum, P. et al. Gonosomal mosaicism for an NF1 deletion in a sperm donor: evidence of the need for coordinated, long-term communication of health information among relevant parties. Hum. Reprod. 27, 1223–1226 (2012).

    Article  CAS  PubMed  Google Scholar 

  11. Maertens, O. et al. Molecular dissection of isolated disease features in mosaic neurofibromatosis type 1. Am. J. Hum. Genet. 81, 243–251 (2007).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  12. Messiaen, L. et al. Mosaic type-1 NF1 microdeletions as a cause of both generalized and segmental neurofibromatosis type-1 (NF1). Hum. Mutat. 32, 213–219 (2011).

    Article  CAS  PubMed  Google Scholar 

  13. Lee, N. P. et al. Identification of clinically relevant mosaicism in type I hereditary haemorrhagic telangiectasia. J. Med. Genet. 48, 353–357 (2011).

    Article  CAS  PubMed  Google Scholar 

  14. Best, D. H. et al. Mosaic ACVRL1 and ENG mutations in hereditary haemorrhagic telangiectasia patients. J. Med. Genet. 48, 358–360 (2011).

    Article  CAS  PubMed  Google Scholar 

  15. Harboe, T. L. et al. Mosaicism in segmental Darier disease: an in-depth molecular analysis quantifying proportions of mutated alleles in various tissues. Dermatology 222, 292–296 (2011).

    Article  PubMed  Google Scholar 

  16. Happle, R. Cutaneous manifestation of lethal genes. Hum. Genet. 72, 280 (1986).

    Article  CAS  PubMed  Google Scholar 

  17. Happle, R. Lethal genes surviving by mosaicism: a possible explanation for sporadic birth defects involving the skin. J. Am. Acad. Dermatol. 16, 899–906 (1987).

    Article  CAS  PubMed  Google Scholar 

  18. McCune, D. & Bruch, H. Progress in pediatrics: osteodystrophia fibrosa. Am. J. Dis. Child 54, 806–848 (1937).

    Article  Google Scholar 

  19. Albright, F., Butle, A. M., Hampton, A. O. & Smith, P. Syndrome characterized by osteitis fibrosa disseminata, areas of pigmentation and endocrine dysfunction, with precocious puberty in females: report of five cases. N. Engl. J. Med. 216, 727–746 (1937).

    Article  Google Scholar 

  20. Happle, R. The McCune–Albright syndrome: a lethal gene surviving by mosaicism. Clin. Genet. 29, 321–324 (1986).

    Article  CAS  PubMed  Google Scholar 

  21. Weinstein, L. S. et al. Activating mutations of the stimulatory G protein in the McCune–Albright syndrome. N. Engl. J. Med. 325, 1688–1695 (1991). This is the landmark paper that describes the identification of mosaic mutations that cause the McCune–Albright syndrome.

    Article  CAS  PubMed  Google Scholar 

  22. Wiedemann, H. R. et al. The Proteus syndrome. Partial gigantism of the hands and/or feet, nevi, hemihypertrophy, subcutaneous tumors, macrocephaly or other skull anomalies and possible accelerated growth and visceral affections. Eur. J. Pediatr. 140, 5–12 (1983).

    Article  CAS  PubMed  Google Scholar 

  23. Happle, R. How many epidermal nevus syndromes exist? A clinicogenetic classification. J. Am. Acad. Dermatol. 25, 550–556 (1991).

    Article  CAS  PubMed  Google Scholar 

  24. Wallis, G. A., Starman, B. J., Zinn, A. B. & Byers, P. H. Variable expression of osteogenesis imperfecta in a nuclear family is explained by somatic mosaicism for a lethal point mutation in the alpha 1(I) gene (COL1A1) of type I collagen in a parent. Am. J. Hum. Genet. 46, 1034–1040 (1990).

    CAS  PubMed  PubMed Central  Google Scholar 

  25. Williams, C. J. & Prockop, D. J. Synthesis and processing of a type I procollagen containing shortened pro-alpha 1(I) chains by fibroblasts from a patient with osteogenesis imperfecta. J. Biol. Chem. 258, 5915–5921 (1983).

    Article  CAS  PubMed  Google Scholar 

  26. Lamande, S. R., Dahl, H. H., Cole, W. G. & Bateman, J. F. Characterization of point mutations in the collagen COL1A1 and COL1A2 genes causing lethal perinatal osteogenesis imperfecta. J. Biol. Chem. 264, 15809–15812 (1989).

    Article  CAS  PubMed  Google Scholar 

  27. Byers, P. H., Tsipouras, P., Bonadio, J. F., Starman, B. J. & Schwartz, R. C. Perinatal lethal osteogenesis imperfecta (OI type II): a biochemically heterogeneous disorder usually due to new mutations in the genes for type I collagen. Am. J. Hum. Genet. 42, 237–248 (1988).

    CAS  PubMed  PubMed Central  Google Scholar 

  28. Goriely, A. & Wilkie, A. O. Paternal age effect mutations and selfish spermatogonial selection: causes and consequences for human disease. Am. J. Hum. Genet. 90, 175–200 (2012). This review elegantly summarizes the disorders that manifest a paternal age effect and the biological basis of this phenomenon.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  29. Conlin, L. K. et al. Mechanisms of mosaicism, chimerism and uniparental disomy identified by single nucleotide polymorphism array analysis. Hum. Mol. Genet. 19, 1263–1275 (2010). This paper demonstrates the utility of the SNP array for detection of mosaicism and elucidation of the mechanisms by which the mosaicism arises.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  30. Gottlieb, B., Beitel, L. K., Alvarado, C. & Trifiro, M. A. Selection and mutation in the “new” genetics: an emerging hypothesis. Hum. Genet. 127, 491–501 (2010).

    Article  CAS  PubMed  Google Scholar 

  31. Hirschhorn, K., Decker, W. H. & Cooper, H. L. Human intersex with chromosome mosaicism of type XY/XO. Report of a case. N. Engl. J. Med. 263, 1044–1048 (1960).

    Article  CAS  PubMed  Google Scholar 

  32. Erickson, R. P. Somatic gene mutation and human disease other than cancer: an update. Mutat. Res. 705, 96–106 (2010).

    Article  CAS  PubMed  Google Scholar 

  33. Hook, E. B. Exclusion of chromosomal mosaicism: tables of 90%, 95% and 99% confidence limits and comments on use. Am. J. Hum. Genet. 29, 94–97 (1977).

    CAS  PubMed  PubMed Central  Google Scholar 

  34. Rodriguez-Santiago, B. et al. Mosaic uniparental disomies and aneuploidies as large structural variants of the human genome. Am. J. Hum. Genet. 87, 129–138 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  35. Bras, J., Guerreiro, R. & Hardy, J. Use of next-generation sequencing and other whole-genome strategies to dissect neurological disease. Nature Rev. Neurosci. 13, 453–464 (2012).

    Article  CAS  Google Scholar 

  36. Mardis, E. R. The impact of next-generation sequencing technology on genetics. Trends Genet. 24, 133–141 (2008). This is a thorough review of the basics of NGS technologies that underlie many of the recent discoveries of mosaic disorders.

    Article  CAS  PubMed  Google Scholar 

  37. Miller, J. F. et al. Fetal loss after implantation. A prospective study. Lancet 2, 554–556 (1980).

    Article  CAS  PubMed  Google Scholar 

  38. Hassold, T. et al. Human aneuploidy: incidence, origin, and etiology. Environ. Mol. Mutagen. 28, 167–175 (1996).

    Article  CAS  PubMed  Google Scholar 

  39. Vanneste, E. et al. Chromosome instability is common in human cleavage-stage embryos. Nature Med. 15, 577–583 (2009). This paper uses array CGH to reveal the surprisingly high frequency of chromosome abnormalities in the very early embryo.

    Article  CAS  PubMed  Google Scholar 

  40. Hassold, T. J. & Jacobs, P. A. Trisomy in man. Annu. Rev. Genet. 18, 69–97 (1984).

    Article  CAS  PubMed  Google Scholar 

  41. Daber, R. et al. Mosaic trisomy 17: variable clinical and cytogenetic presentation. Am. J. Med. Genet. A 155, 2489–2495 (2011).

    Article  CAS  Google Scholar 

  42. Conlin, L. K. et al. Molecular analysis of ring chromosome 20 syndrome reveals two distinct groups of patients. J. Med. Genet. 48, 1–9 (2011).

    Article  CAS  PubMed  Google Scholar 

  43. Hsu, L. Y. et al. Incidence and significance of chromosome mosaicism involving an autosomal structural abnormality diagnosed prenatally through amniocentesis: a collaborative study. Prenat. Diagn. 16, 1–28 (1996).

    Article  CAS  PubMed  Google Scholar 

  44. Kelker, W. et al. Loss of 18q and homozygosity for the DCC locus: possible markers for clinically aggressive squamous cell carcinoma. Anticancer Res. 16, 2365–2372 (1996).

    CAS  PubMed  Google Scholar 

  45. Gijsbers, A. C. et al. Three new cases with a mosaicism involving a normal cell line and a cryptic unbalanced autosomal reciprocal translocation. Eur. J. Med. Genet. 54, e409–e412 (2011).

    Article  PubMed  Google Scholar 

  46. Robberecht, C. et al. Meiotic errors followed by two parallel postzygotic trisomy rescue events are a frequent cause of constitutional segmental mosaicism. Mol. Cytogenet. 5, 19 (2012).

    Article  PubMed  PubMed Central  Google Scholar 

  47. Hook, E. B. & Warburton, D. The distribution of chromosomal genotypes associated with Turner's syndrome: livebirth prevalence rates and evidence for diminished fetal mortality and severity in genotypes associated with structural X abnormalities or mosaicism. Hum. Genet. 64, 24–27 (1983).

    Article  CAS  PubMed  Google Scholar 

  48. Raffel, L. J., Mohandas, T. & Rimoin, D. L. Chromosomal mosaicism in the Killian/Teschler-Nicola syndrome. Am. J. Med. Genet. 24, 607–611 (1986).

    Article  CAS  PubMed  Google Scholar 

  49. Ballif, B. C. et al. Detection of low-level mosaicism by array CGH in routine diagnostic specimens. Am. J. Med. Genet. A 140, 2757–2767 (2006).

    Article  PubMed  Google Scholar 

  50. Cheung, S. W. et al. Microarray-based CGH detects chromosomal mosaicism not revealed by conventional cytogenetics. Am. J. Med. Genet. A 143, 1679–1686 (2007).

    Article  Google Scholar 

  51. Laurie, C. C. et al. Detectable clonal mosaicism from birth to old age and its relationship to cancer. Nature Genet. 44, 642–650 (2012).

    Article  CAS  PubMed  Google Scholar 

  52. Jacobs, K. B. et al. Detectable clonal mosaicism and its relationship to aging and cancer. Nature Genet. 44, 651–658 (2012).

    Article  CAS  PubMed  Google Scholar 

  53. Abyzov, A. et al. Somatic copy number mosaicism in human skin revealed by induced pluripotent stem cells. Nature 492, 438–442 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  54. Piotrowski, A. et al. Somatic mosaicism for copy number variation in differentiated human tissues. Hum. Mutat. 29, 1118–1124 (2008). This work investigates the frequency of copy number alterations in over 30 tissue samples from the same individual, revealing alterations that occur in only a single tissue in some cases, demonstrating the potential importance of tissue-specific mosaicism for human disease.

    Article  PubMed  Google Scholar 

  55. Bruder, C. E. et al. Phenotypically concordant and discordant monozygotic twins display different DNA copy-number-variation profiles. Am. J. Hum. Genet. 82, 763–771 (2008).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  56. Breckpot, J. et al. Differences in copy number variation between discordant monozygotic twins as a model for exploring chromosomal mosaicism in congenital heart defects. Mol. Syndromol. 2, 81–87 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  57. Hafner, C. et al. Keratinocytic epidermal nevi are associated with mosaic RAS mutations. J. Med. Genet. 49, 249–253 (2012).

    Article  CAS  PubMed  Google Scholar 

  58. Hafner, C. et al. Oncogenic PIK3CA mutations occur in epidermal nevi and seborrheic keratoses with a characteristic mutation pattern. Proc. Natl Acad. Sci. USA 104, 13450–13454 (2007). A candidate gene approach identifies PIK3CA as the cause of several mosaic dermatologic lesions. This is the first of a series of papers that demonstrates the importance of this pathway in mosaic dermatological disorders.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  59. Hafner, C. et al. Mosaicism of activating FGFR3 mutations in human skin causes epidermal nevi. J. Clin. Invest. 116, 2201–2207 (2006).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  60. Lindhurst, M. J. et al. A mosaic activating mutation in AKT1 associated with the Proteus syndrome. New Engl. J. Med. 365, 611–619 (2011). Here, the authors describe the first application of NGS to mosaic disorders in humans in a disorder that most famously afflicted Joseph Carey Merrick.

    Article  CAS  PubMed  Google Scholar 

  61. Lee, J. H. et al. De novo somatic mutations in components of the PI3K–AKT3–mTOR pathway cause hemimegalencephaly. Nature Genet. 44, 941–945 (2012).

    Article  CAS  PubMed  Google Scholar 

  62. Poduri, A. et al. Somatic activation of AKT3 causes hemispheric developmental brain malformations. Neuron 74, 41–48 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  63. Riviere, J. B. et al. De novo germline and postzygotic mutations in AKT3, PIK3R2 and PIK3CA cause a spectrum of related megalencephaly syndromes. Nature Genet. 44, 934–940 (2012).

    Article  CAS  PubMed  Google Scholar 

  64. Lindhurst, M. J. et al. Mosaic overgrowth with fibroadipose hyperplasia is caused by somatic activating mutations in PIK3CA. Nature Genet. 44, 928–933 (2012).

    Article  CAS  PubMed  Google Scholar 

  65. Kurek, K. C. et al. Somatic mosaic activating mutations in PIK3CA cause CLOVES syndrome. Am. J. Hum. Genet. 90, 1108–1115 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  66. Groesser, L. et al. Postzygotic HRAS and KRAS mutations cause nevus sebaceous and Schimmelpenning syndrome. Nature Genet. 44, 783–787 (2012).

    Article  CAS  PubMed  Google Scholar 

  67. Treon, S. P. et al. MYD88 L265P somatic mutation in Waldenström's macroglobulinemia. N. Engl. J. Med. 367, 826–833 (2012).

    Article  CAS  PubMed  Google Scholar 

  68. Shiang, R. et al. Mutations in the transmembrane domain of FGFR3 cause the most common genetic form of dwarfism, achondroplasia. Cell 78, 335–342 (1994).

    Article  CAS  PubMed  Google Scholar 

  69. Rousseau, F. et al. Mutations in the gene encoding fibroblast growth factor receptor-3 in achondroplasia. Nature 371, 252–254 (1994).

    Article  CAS  PubMed  Google Scholar 

  70. Choate, K. A. et al. Mitotic recombination in patients with ichthyosis causes reversion of dominant mutations in KRT10. Science 330, 94–97 (2010). This work documents the startling finding of the role of mitotic recombination in revertant mosaicism by demonstration of the correlation with normal patches of skin in a patient with icthyosis (and a documented mutation) with a normal genotype.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  71. Jonkman, M. F. & Pasmooij, A. M. Realm of revertant mosaicism expanding. J. Invest. Dermatol. 132, 514–516 (2012).

    Article  CAS  PubMed  Google Scholar 

  72. Kearney, H. M., Kearney, J. B. & Conlin, L. K. Diagnostic implications of excessive homozygosity detected by SNP-based microarrays: consanguinity, uniparental disomy, and recessive single-gene mutations. Clin. Lab. Med. 31, 595–613 (2011).

    Article  PubMed  Google Scholar 

  73. Lindstrom, D. L., Leverich, C. K., Henderson, K. A. & Gottschling, D. E. Replicative age induces mitotic recombination in the ribosomal RNA gene cluster of Saccharomyces cerevisiae. PLoS Genet. 7, e1002015 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  74. Romanelli, V. et al. Beckwith–Wiedemann syndrome and uniparental disomy 11p: fine mapping of the recombination breakpoints and evaluation of several techniques. Eur. J. Hum. Genet. 19, 416–421 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  75. Cooper, W. N., Curley, R., Macdonald, F. & Maher, E. R. Mitotic recombination and uniparental disomy in Beckwith–Wiedemann syndrome. Genomics 89, 613–617 (2007).

    Article  CAS  PubMed  Google Scholar 

  76. Markert, C. L. & Petters, R. M. Manufactured hexaparental mice show that adults are derived from three embyronic cells. Science 202, 56–58 (1978).

    Article  CAS  PubMed  Google Scholar 

  77. Kalousek, D. K. & Vekemans, M. Confined placental mosaicism and genomic imprinting. Baillieres Best Pract. Res. Clin. Obstet. Gynaecol. 14, 723–730 (2000).

    Article  CAS  PubMed  Google Scholar 

  78. Hoornaert, K. P. et al. The phenotypic spectrum in patients with arginine to cysteine mutations in the COL2A1 gene. J. Med. Genet. 43, 406–413 (2006).

    Article  CAS  PubMed  Google Scholar 

  79. Kingsbury, M. A., Yung, Y. C., Peterson, S. E., Westra, J. W. & Chun, J. Aneuploidy in the normal and diseased brain. Cell. Mol. Life Sci. 63, 2626–2641 (2006).

    Article  CAS  PubMed  Google Scholar 

  80. Yurov, Y. B. et al. Unexplained autism is frequently associated with low-level mosaic aneuploidy. J. Med. Genet. 44, 521–525 (2007).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  81. Sebat, J. et al. Strong association of de novo copy number mutations with autism. Science 316, 445–449 (2007).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  82. Marshall, C. R. et al. Structural variation of chromosomes in autism spectrum disorder. Am. J. Hum. Genet. 82, 477–488 (2008).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  83. Gollob, M. H. et al. Somatic mutations in the connexin 40 gene (GJA5) in atrial fibrillation. N. Engl. J. Med. 354, 2677–2688 (2006).

    Article  CAS  PubMed  Google Scholar 

  84. Malan, V., Vekemans, M. & Turleau, C. Chimera and other fertilization errors. Clin. Genet. 70, 363–373 (2006).

    Article  CAS  PubMed  Google Scholar 

  85. Winberg, J. et al. Chimerism resulting from parthenogenetic activation and dispermic fertilization. Am. J. Med. Genet. A 152, 2277–2286 (2010).

    Article  Google Scholar 

  86. Yamazawa, K. et al. Parthenogenetic chimaerism/mosaicism with a Silver–Russell syndrome-like phenotype. J. Med. Genet. 47, 782–785 (2010).

    Article  CAS  PubMed  Google Scholar 

  87. Shin, S. Y., Yoo, H. W., Lee, B. H., Kim, K. S. & Seo, E. J. Identification of the mechanism underlying a human chimera by SNP array analysis. Am. J. Med. Genet. A 158, 2119–2123 (2012).

    Article  CAS  Google Scholar 

  88. Wilson, M. et al. The clinical phenotype of mosaicism for genome-wide paternal uniparental disomy: two new reports. Am. J. Med. Genet. A 146, 137–148 (2008).

    Article  CAS  Google Scholar 

  89. Romanelli, V. et al. Constitutional mosaic genome-wide uniparental disomy due to diploidisation: an unusual cancer-predisposing mechanism. J. Med. Genet. 48, 212–216 (2011).

    Article  PubMed  Google Scholar 

  90. Yu, N. et al. Disputed maternity leading to identification of tetragametic chimerism. N. Engl. J. Med. 346, 1545–1552 (2002).

    Article  PubMed  Google Scholar 

  91. Vogt, J. et al. Monozygotic twins discordant for neurofibromatosis type 1 due to a postzygotic NF1 gene mutation. Hum. Mutat. 32, E2134–E2147 (2011).

    Article  CAS  PubMed  Google Scholar 

  92. Kaplan, L. et al. Monozygotic twins discordant for neurofibromatosis 1. Am. J. Med. Genet. A 152, 601–606 (2010).

    Article  Google Scholar 

  93. Fraga, M. F. et al. Epigenetic differences arise during the lifetime of monozygotic twins. Proc. Natl Acad. Sci. USA 102, 10604–10609 (2005).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  94. Harder, A. et al. Monozygotic twins with neurofibromatosis type 1 (NF1) display differences in methylation of NF1 gene promoter elements, 5′ untranslated region, exon and intron 1. Twin Res. Hum. Genet. 13, 582–594 (2010).

    Article  PubMed  Google Scholar 

  95. Conlin, L. K. et al. Utility of SNP arrays in detecting, quantifying, and determining meiotic origin of tetrasomy 12p in blood from individuals with Pallister–Killian syndrome. Am. J. Med. Genet. A 158, 3046–3053 (2012).

    Article  CAS  Google Scholar 

Download references

Acknowledgements

L.G.B. is funded by the Intramural Research Program of the US National Human Genome Research Institute of the National Institutes of Health. He is an uncompensated consultant to the Illumina Corporation and receives an honorarium from the Wiley–Blackwell Corporation for editing activities. N.B.S. is funded by the US National Institute of Diabetes and Digestive and Kidney Diseases, the US National Human Genome Research Institute, the Ring14 Association and is supported by the Fred and Suzanne Biesecker Liver Center in the Research Institute at the Children's Hospital of Philadelphia. She is grateful, as always, to L. Conlin, both for scientific discussion and for the generation of the drafts of figures included in this work.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Leslie G. Biesecker.

Ethics declarations

Competing interests

Leslie G. Biesecker is an uncompensated consultant to the Illumina Corporation. He receives honoraria from the Wiley–Blackwell Corporation for editing activities. Nancy B. Spinner declares no competing financial interests.

PowerPoint slides

Glossary

Germline mosaicism

The diploid germ cell precursors in the gonad are heterogeneous: some have a mutation and some do not.

Somatic mosaicism

The non-germ cells of the body are heterogeneous: some have a mutation and some do not.

Lines of Blaschko

Streaky lines visible on the skin that radiate inferolaterally from the area over the dorsal spine. They are the consequence of the migration of neuroectodermal cells from the closure of the neural tube.

Heterochromia irides

Describes an individual with irises that are of distinctly different colours.

Aneuploidy

A human cell with other than a multiple of 23 chromosomes.

Structural alterations

Describes genomic changes that can be balanced, large-scale rearrangements without copy number changes (such as translocations and inversions) or large deletions and duplications that result in copy number changes.

Hyperkeratosis

A dermatological condition consisting of a thickening of the keratin-rich layer of the epidermis.

Atrophy

A condition of tissue volume loss due to disuse or lack of trophic stimulation.

Soma

All cells of the body other than the germ cells.

Expressivity

The degree to which a trait manifests in an individual who has some recognizable manifestation of the disorder.

Segmental mosaicism

This is a subtype of somatic mosaicism: an anatomically recognizable portion of the body has cells that have a mutation that is not present in other parts of the body.

Hereditary haemorrhagic telangiectasia

A disorder of vessel dysplasia that can be caused by mutations in a number of genes.

Darier–White disease

A disorder of heterogeneous skin lesions, which can include warty papules, plaques, and seborrhoea, caused by mutations in ATP2A2.

Penetrance

The proportion of individuals with a specific phenotype among carriers of a particular genotype.

Discordant monozygotic twins

Twins that result from the fission of a single fertilized inner cell mass but who have a distinct phenotypic difference between them.

Bony hyperostoses

Focal overgrowths of bone and osteoid (partially calcified bone matrix).

Café-au-lait spots

Light brown macules of the skin that are a common manifestation of neurofibromatosis, McCune–Albright syndrome and several of other disorders.

Proteus syndrome

A disorder of mosaic, progressive overgrowth caused by mutation in AKT1.

Nevus sebaceous

A skin lesion characterized by overgrowth of sebaceous glands.

Pallister–Killian syndrome

A disorder of dysmorphic features and intellectual disability caused by mosaic tetrasomy of chromosome 12p.

Osteogenesis imperfecta type II

A disorder of bone fragility and short stature caused by mutations in COL1A1 or COL1A2.

Pseudoachondroplasia

A disorder of short stature and dysmorphic features, generally less severe than achondroplasia, caused by mutations in COMP.

Achondropasia

A disorder with severe short stature and dysmorphic features caused by mutations in FGFR3.

Nondisjunction

The failure of chromosomes to segregate normally during cell division, resulting in the mis-segregation of chromosomes into daughter cells. Nondisjunction at meiosis I results in products with additional or missing chromosomes that are genetically distinct (homologues), whereas nondisjunction at meiosis II results in missing or extra sister chromatids.

Cat eye syndrome

A syndrome of dysmorphic features and intellectual disability caused by duplication of a segment of chromosome 22q.

Supernumerary

Extra copies of either a whole chromosome or of a chromosome segment that contains a centromere.

Loss of heterozygosity

Describes that status of a cell or tissue that was originally heterozygous at a genetic locus but owing to somatic alterations is subsequently homozygous or hemizygous.

Uniparental disomy

(UPD). When both chromosomes of a homologous pair are inherited from the same parent. When these chromosomes are different, this is uniparental heterodisomy. When these chromosomes are identical through duplication, this is uniparental isodisomy.

Hemimegencephaly

A descriptor for a brain that has substantial asymmetry, with one side being abnormally large and commonly malformed.

Fibroadipose overgrowth

A manifestation of overgrowth that includes excess fatty tissue with fibrous strands caused by somatic mutation of PIK3CA.

Waldenström macroglobulinaemia

A malignant B cell neoplasm with lymphoplasmacytic infiltration of bone marrow and excess monoclonal immunoglobulin M.

Hyperplastic

An enlarged tissue caused by an increased number of cells.

Hypertrophic

An enlarged tissue caused by enlarged cells.

Beckwith–Wiedemann syndrome

An overgrowth and tumour susceptibility syndrome caused by imprinting defects of 11p15.

Costello syndrome

A syndrome of dysmorphic features, intellectual disability and tumour predisposition caused by mutations in the HRAS gene. A member of the rasopathy family of phenotypes.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Biesecker, L., Spinner, N. A genomic view of mosaicism and human disease. Nat Rev Genet 14, 307–320 (2013). https://doi.org/10.1038/nrg3424

Download citation

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nrg3424

This article is cited by

Search

Quick links

Nature Briefing: Translational Research

Sign up for the Nature Briefing: Translational Research newsletter — top stories in biotechnology, drug discovery and pharma.

Get what matters in translational research, free to your inbox weekly. Sign up for Nature Briefing: Translational Research