A survey of 1,000 cases referred for cytogenetic study to King Khalid University Hospital, Saudi Arabia

We reviewed cytogenetic studies that have been done in 1,000 consecutive no n-oncology samples that were referred to the Cytogenetics Unit at King Khal id University Hospital, Riyadh, Saudi Arabia. The cases were grouped accord ing to the referral diagnosis and the requested cytogenetic service, The fr equency of the different types of numerical and structural abnormalities wa s determined and the relative frequency of cases with abnormal karyotype wa s calculated in each group, This study should assist physicians in Saudi Ar abia and surrounding countries by increasing the awareness of the frequency of cytogenetic abnormality in different diagnostic groups, It also gives f igures for comparison with other countries and research centers.