DOWNS-SYNDROME IN SAUDI-ARABIA - INCIDENCE AND CYTOGENETICS

A study has been carried out in Riyadh to determine the incidence and distribution of Down's syndrome births during a 9-year period from Jul y 1982 to June 1991. Down's syndrome was ascertained in 42 (23 females and 19 males) of 23,261 consecutive babies born alive to Saudi women, giving an incidence of 1 in 554 live births (1.8 per 1,000). A trend towards an increased incidence of Down's syndrome with advanced matern al age or increased maternal parity was found. Cytogenetic studies wer e performed on 37 cases of which all but 1 were non-disjunction trisom y 21, while the remaining infant had a translocation. This study provi des the first step for further epidemiological surveys of Down's syndr ome in the Kingdom of Saudi Arabia in order to prepare the ground for an effective antenatal screening programme for chromosomal disorders.