XYYYY syndrome, also known as 49,XYYYY, is an exceptionally rare chromosomal disorder in which a male human has three additional copies of the Y chromosome. Only seven non-mosaic cases of the disorder have ever been recorded in the medical literature, as well as five mosaic cases, of which two had more 48,XYYY than 49,XYYYY cells.[1] Due to the extreme rarity of the disorder, little is understood about it,[2] and the phenotype appears to be variable.[3]
- ^ Demily C, Poisson A, Peyroux E, Gatellier V, Nicolas A, Rigard C, Schluth-Bolard C, Sanlaville D, Rossi M (2017). "Autism spectrum disorder associated with 49,XYYYY: case report and review of the literature". BMC Medical Genetics. 18 (9): 9. doi:10.1186/s12881-017-0371-1. PMC 5282903. PMID 28137251.
- ^ Linden MG, Bender BG, Robinson A (October 1995). "Sex chromosome tetrasomy and pentasomy". Pediatrics. 96 (4): 672–682. doi:10.1542/peds.96.4.672. PMID 7567329.
- ^ Frey-Mahn G, Behrendt G, Geiger K, Sohn C, Schäfer D, Miny P (12 December 2002). "Y chromosomal polysomy: A unique case of 49,XYYYY in amniotic fluid cells". American Journal of Medical Genetics. 118A (2): 184–186. doi:10.1002/ajmg.a.10051. PMID 12655500. S2CID 37103837.