Legius syndrome is a condition characterized by changes in skin coloring (pigmentation). Almost all affected individuals have multiple café-au-lait spots, which are flat patches on the skin that are darker than the surrounding area. Another pigmentation change, freckles in the armpits and groin, may occur in some affected individuals.

Other signs and symptoms of Legius syndrome may include an abnormally large head (macrocephaly) and unusual facial characteristics. Although most people with Legius syndrome have normal intelligence, some affected individuals have been diagnosed with learning disabilities, attention-deficit disorder (ADD), or attention-deficit/hyperactivity disorder (ADHD).

Many of the signs and symptoms of Legius syndrome also occur in a similar disorder called neurofibromatosis type 1. It can be difficult to tell the two disorders apart in early childhood. However, the features of the two disorders differ later in life.

The prevalence of Legius syndrome is unknown. Many individuals with this disorder are likely misdiagnosed because the signs and symptoms of Legius syndrome are similar to those of neurofibromatosis type 1.

Mutations in the SPRED1 gene cause Legius syndrome. The SPRED1 gene provides instructions for making the Spred-1 protein. This protein controls (regulates) an important cell signaling pathway that is involved in the growth and division of cells (proliferation), the process by which cells mature to carry out specific functions (differentiation), cell movement, and the self-destruction of cells (apoptosis). Mutations in the SPRED1 gene lead to a nonfunctional protein that can no longer regulate the pathway, resulting in overactive signaling. It is unclear how mutations in the SPRED1 gene cause the signs and symptoms of Legius syndrome.

Genetic Testing Information

• Genetic Testing Registry: Legius syndrome

Genetic and Rare Diseases Information Center

• Legius syndrome

Patient Support and Advocacy Resources

• National Organization for Rare Disorders (NORD)

Clinical Trials

• ClinicalTrials.gov

Catalog of Genes and Diseases from OMIM

• LEGIUS SYNDROME; LGSS

Scientific Articles on PubMed

• PubMed

• Brems H, Chmara M, Sahbatou M, Denayer E, Taniguchi K, Kato R, Somers R, Messiaen L, De Schepper S, Fryns JP, Cools J, Marynen P, Thomas G, Yoshimura A, Legius E. Germline loss-of-function mutations in SPRED1 cause a neurofibromatosis 1-like phenotype. Nat Genet. 2007 Sep;39(9):1120-6. doi: 10.1038/ng2113. Epub 2007 Aug 19. Citation on PubMed
• Denayer E, Chmara M, Brems H, Kievit AM, van Bever Y, Van den Ouweland AM, Van Minkelen R, de Goede-Bolder A, Oostenbrink R, Lakeman P, Beert E, Ishizaki T, Mori T, Keymolen K, Van den Ende J, Mangold E, Peltonen S, Brice G, Rankin J, Van Spaendonck-Zwarts KY, Yoshimura A, Legius E. Legius syndrome in fourteen families. Hum Mutat. 2011 Jan;32(1):E1985-98. doi: 10.1002/humu.21404. Citation on PubMed or Free article on PubMed Central
• Legius E, Stevenson D. Legius Syndrome. 2010 Oct 14 [updated 2020 Aug 6]. In: Adam MP, Feldman J, Mirzaa GM, Pagon RA, Wallace SE, Amemiya A, editors. GeneReviews(R) [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2025. Available from http://www.ncbi.nlm.nih.gov/books/NBK47312/ Citation on PubMed
• Messiaen L, Yao S, Brems H, Callens T, Sathienkijkanchai A, Denayer E, Spencer E, Arn P, Babovic-Vuksanovic D, Bay C, Bobele G, Cohen BH, Escobar L, Eunpu D, Grebe T, Greenstein R, Hachen R, Irons M, Kronn D, Lemire E, Leppig K, Lim C, McDonald M, Narayanan V, Pearn A, Pedersen R, Powell B, Shapiro LR, Skidmore D, Tegay D, Thiese H, Zackai EH, Vijzelaar R, Taniguchi K, Ayada T, Okamoto F, Yoshimura A, Parret A, Korf B, Legius E. Clinical and mutational spectrum of neurofibromatosis type 1-like syndrome. JAMA. 2009 Nov 18;302(19):2111-8. doi: 10.1001/jama.2009.1663. Citation on PubMed
• Pasmant E, Sabbagh A, Hanna N, Masliah-Planchon J, Jolly E, Goussard P, Ballerini P, Cartault F, Barbarot S, Landman-Parker J, Soufir N, Parfait B, Vidaud M, Wolkenstein P, Vidaud D, France RN. SPRED1 germline mutations caused a neurofibromatosis type 1 overlapping phenotype. J Med Genet. 2009 Jul;46(7):425-30. doi: 10.1136/jmg.2008.065243. Epub 2009 Apr 14. Citation on PubMed
• Spurlock G, Bennett E, Chuzhanova N, Thomas N, Jim HP, Side L, Davies S, Haan E, Kerr B, Huson SM, Upadhyaya M. SPRED1 mutations (Legius syndrome): another clinically useful genotype for dissecting the neurofibromatosis type 1 phenotype. J Med Genet. 2009 Jul;46(7):431-7. doi: 10.1136/jmg.2008.065474. Epub 2009 May 13. Citation on PubMed