title: Prevalence of Emanuel syndrome: theoretical frequency and surveillance result.
abstract: Constitutional t(11;22)(q23;q11) is the most frequent recurrent non-Robertsonian translocation in humans. Balanced carriers of t(11;22) usually manifest no clinical symptoms, and are often identified after the birth of offspring with an unbalanced form of this translocation, known as Emanuel syndrome. To determine the prevalence of the disorder, we sent surveillance questionnaires to 735 core hospitals in Japan. The observed number of Emanuel syndrome cases was 36 and that of t(11;22) balanced translocation carriers, 40. On the basis of the de novo t(11;22) translocation frequency in sperm from healthy men, we calculated the frequency of the translocations in the general population. Accordingly, the prevalence of Emanuel syndrome was estimated at 1 in 110,000. Based on this calculation, the estimated number of Emanuel syndrome cases in Japan is 1063 and of t(11;22) balanced translocation carriers, 16,604, which are much higher than the numbers calculated from the questionnaire responses. It is possible that this discordance is partly attributable to a lack of disease identification. Further efforts should be made to increase the awareness of Emanuel syndrome to ensure a better quality of life for affected patients and their families.
authors: Division of Molecular Genetics, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Aichi, Japan.
authors: Tamae
authors: T
authors: Ohye
authors: Hidehito
authors: H
authors: Inagaki
authors: Takema
authors: T
authors: Kato
authors: Makiko
authors: M
authors: Tsutsumi
authors: Hiroki
authors: H
authors: Kurahashi
mesh_terms: D025063:Chromosome Disorders / Q000453:epidemiology*; D002972:Cleft Palate / Q000453:epidemiology*; D019295:Computational Biology; D062665:Epidemiological Monitoring; D005260:Female; D006330:Heart Defects, Congenital / Q000453:epidemiology*; D006801:Humans; D008607:Intellectual Disability / Q000453:epidemiology*; D007564:Japan / Q000453:epidemiology; D008297:Male; D009123:Muscle Hypotonia / Q000453:epidemiology*; D015995:Prevalence; D011795:Surveys and Questionnaires
keywords: 22); Emanuel syndrome; prevalence; surveillance; t(11; translocation