Biomedical subjects
Publications and source records attributed to B Zoll.
Linkage between the loci for fraXq of Martin-Bell syndrome and factor IX was studied in nine families exhibiting this syndrome by means of a restriction fragment length polymorphism at the factor IX locus. Computer analysis of the data indicates there to be no evidence for close linkage between the syndrome and the factor IX locus.
Cytogenetic investigations were carried out on 103 women presenting with either primary (n = 88) or secondary (n = 15) amenorrhea. A sex chromosome anomaly was found in 26% and 33% of these patients, respectively. Other studies on women with primary amenorrhea have found a similar or even higher percentage of patients with an abnormal karyotype. It is therefore suggested that all women with absence of menstruation after the age of 16 years should be investigated cytogenetically. The surprisingly high percentage of pathological karyotypes among the secondary amenorrhea group does indicate that sex chromosome anomalies cannot be ruled out in women who have had apparently normal ovarian function for at least some time, and therefore more patients from this group should be selected for chromosome analysis.
We report on a fetus with ring chromosome 18 and monosomy 18 mosaicism [mos 45,XX,-18/46,XX,r(18)] detected in cultured amniotic fluid cells at 15 weeks' gestation. Chromosome analysis of fetal blood, cultured chorionic villi and fetal fibroblasts confirmed the aberrant karyotype. The aberrant chromosome complement could not be detected in a short-term culture of chorionic villi (46,XX in 21 metaphases). These findings suggest that the aberrant karyotype was a postzygotic event. Fetal ultrasound was normal and the parents decided to terminate the pregnancy at 21 weeks' gestation. Autopsy revealed multiple abnormalities including facial dysmorphy, partial agenesis of the corpus callosum and an interatrial septal defect.