title: The pattern of Down syndrome among children in Qatar: a population-based study.
abstract: BACKGROUND
  The objective of the present study was to determine the prevalence pattern of Down Syndrome (DS) in children <5 years of age in the State of Qatar. This is a retrospective descriptive study. The study was conducted in the Hamad General Hospital, Women's Hospital, and Rumailah Hospital (Hamad Medical Corporation). A total of 146 children were reported as having DS during the 6-year period from 1 January 2000 to December 31, 2005.
  
  
  METHODS
  The diagnostic classification of definitive DS was made in accordance with criteria based on the International Classification of Disease 10th Revision (ICD-10). The data collected from the medical records included sociodemographic characteristics of the children, genetic and family history, pedigree analysis, and clinical genetic examination.
  
  
  RESULTS
  A total of 146 children were diagnosed with DS during the last 6-year period and the prevalence rate is 19.5 per 10,000 live births. Of these, 40.4% were Qataris and 59.6% were non-Qataris. DS was slightly more common in boys (52.7%) than girls (47.3%). Infants <1 year old had the highest frequency of DS (40.4%), followed by children (1-2) years (26%). The most common abnormality was regular trisomy (98%). Also, one-half of the studied children had congenital heart problems (51.7%). There is a significant relationship between DS and maternal age as reported by other studies in other countries.
  
  
  CONCLUSIONS
  The identification of specific types of chromosomal abnormalities in DS children is important as it enables clinicians to accurately counsel the parent regarding the recurrence risk and available options.
authors.affiliation: Department of Pediatrics, Hamad Medical Corporation , Hamad General Hospital, Doha, Qatar.
authors.forename: Atqah Abdul
authors.initials: AA
authors.lastname: Wahab
authors.forename: Abdulbari
authors.initials: A
authors.lastname: Bener
authors.forename: Amy L
authors.initials: AL
authors.lastname: Sandridge
authors.forename: Georg F
authors.initials: GF
authors.lastname: Hoffmann
mesh_terms: D000328:Adult; D002675:Child, Preschool; D004314:Down Syndrome / Q000150:complications / Q000453:epidemiology* / Q000235:genetics; D005260:Female; D006330:Heart Defects, Congenital / Q000150:complications / Q000453:epidemiology / Q000235:genetics; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008423:Maternal Age; D008875:Middle Aged; D009030:Mosaicism; D011247:Pregnancy; D011780:Qatar / Q000453:epidemiology; D012189:Retrospective Studies; D012744:Sex Ratio