title: [Chromosomal abnormalities in patients from Obstetrics and Gynaecology hospital].
abstract: BACKGROUND
  Chromosomal abnormalities are present in 2-4 % of all newborns, and they cause 20 % of deaths in the first year of life. The estimated prevalence of chromosomal abnormalities is one for each 500-1000 newborns. These abnormalities can be numerical or structural, and they can affect autosomal or sexual chromosomes. They affect from 1 to 3 % of general population, and from 6 to 7 % of individuals with congenital anomalies.
  
  
  METHODS
  Descriptive study, which included all the registries of cytogenetic analysis (of adults and newborns) made in a genetic laboratory in a period of 14 years. The prevalence of polymorphisms and chromosomal abnormalities in the patients from the Hospital de Ginecoobstetricia 23, Instituto Mexicano del Seguro Social (Monterrey, Nuevo León) was assessed.
  
  
  RESULTS
  Of 4006 cytogenetic studies, 253 (6.3 %) did not show in vitro growth, 2667 (66.5 %) were normal, and 1175 (29.3 %) were abnormal. Of these, 614 (52.2 %) had polymorphisms, and 561 (47.7 %) structural or numerical chromosomal abnormalities. In regards to these chromosomopathies (561), trisomy 21 was observed in 429 (36.5 %); Turner's syndrome, in 84 (7.1 %); trisomy 18, in 57 (4.8 %); and trisomy 13, in 32 (2.7 %). With G-band technique, we found 93 % of in vitro cell growth.
  
  
  CONCLUSIONS
  Of these studies, 55 % was performed due to non-numerical abnormalities; 14.4 %, due to structural abnormalities; and the rest, due to polymorphisms.
authors.affiliation: Departamento de Genética, Hospital de Ginecoobstetricia 23, Instituto Mexicano del Seguro Social, Monterrey, Nuevo León. richdzher@hotmail.com; rjorgeh246@hotmail.com.
authors.forename: Ricardo Jorge
authors.initials: RJ
authors.lastname: Hernández-Herrera
authors.forename: Luz
authors.initials: L
authors.lastname: Rojas-Patlán
authors.forename: Rosa María
authors.initials: RM
authors.lastname: Garza-Pérez
authors.forename: Martha
authors.initials: M
authors.lastname: Dávila-Rodríguez
authors.forename: Elva Irene
authors.initials: EI
authors.lastname: Cortés-Gutiérrez
authors.forename: Emerson Odón
authors.initials: EO
authors.lastname: García-Rodríguez
authors.forename: Roberto Raúl
authors.initials: RR
authors.lastname: Hernández-Hernández
mesh_terms: D000328:Adult; D002869:Chromosome Aberrations / Q000706:statistics & numerical data*; D025063:Chromosome Disorders / Q000453:epidemiology*; D005260:Female; D006176:Gynecology; D006771:Hospitals, Maternity; D006779:Hospitals, Public; D006801:Humans; D007231:Infant, Newborn; D008800:Mexico / Q000453:epidemiology; D015995:Prevalence; D012042:Registries
keywords: Chromosomal abnormalities; Newborn infant