'n Analise van sitogenetiese studies op 2 334 pasiente
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The chromosome results of a series of 2 334 patients referred for cytogenetic analysis during 1966-1977 were tabulated by computer. The patients were grouped according to indications for referral, the main indications being amenorrhoea, congenital abnormalities, infertility and sex abnormalities. Among the patients with amenorrhoea, the largest percentage of chromosome abnormalities (28%) occurred in the group of 86 cases of primary amenorrhoea, whereas the percentage of chromosome abnormalities in the group of 113 secondary amenorrhoea patients was only 3.5. Of 615 patients with congenital abnormalities, 345 were referred for Down syndrome, of whom 64.6% had an abnormal chromosome constitution with extra chromosome 21 material. In the remainder of patients with chromosome abnormalities, trisomy 13 and trisomy 18 featured, although not all were referred as clearcut cases of Patau's or Edward's syndrome, the respective corresponding phenotypes. The incidence of chromosome abnormalities among patients with congenital abnormalities not typical of the above mentioned three syndromes was low (8.4%), with diverse chromosome constitutions. Among the infertile patients, 70 had azoospermia and 185 had oligozoospermia. The incidence of chromosome abnormalities within the two groups was 11.4% and 8.1% respectively. Of the 233 patients referred with sex abormalities, the highest proportion of chromosome abnormalities was found among those with Turner's and Klinefelter's syndromes. In these two classes 10 patients had a 45,XO or abnormal X chromosome constitution and 6 had 47,XXY karyotypes respectively. Another group of cases was classed among miscellaneous indications for referral. Of 61 amniotic fluid samples for prenatal diagnosis, there were 2 cases of trisomy 21. Of 154 male and female patients with a history of repeated miscarriages, 2.6% had chromosome abnormalities. Of a group of 62 patients with myelo- and lymphoproliferative disorders whose blood and/or bone marrow samples were included, 7 had chromosome abnormalities. Among 61 mentally retarded patients referred, 3 had mosaic chromosome constitutions. In every case a normal cell line was present. No chromosome abnormalities were found in 23 patients with retarded growth. 88 spontaneous and 19 ectopic abortusses showed 10.5% and 10.2% chromosome abnormalities respectively. Relatives of the original index patients were found to have chromosome abnormalities in 7.3% of cases, in most instances a rearrangement corresponding to that of the index patient. The significance of the observed abnormalities in this group of 2 334 individuals, when pooled, is discussed. The distribution of the chromosome abnormalities was 81% autosomal (largely as a result of chromosome 21) and 19% sex chromosomal. Additionally, 80% of all abnormalities were numerical and 20% were structural chromosome abnormalities in both autosomes and sex chromosomes.