Résumé
The study aimed to evaluate the role of nucleolus organizer region [NOR] heteromorphism as an etiological factor for parental nondisjunction in Down syndrome by comparing 25 patients affected by Down syndrome, and their parents with a control group of 80 non-affected Egyptians. All parents had normal karyotypes. The average modal number per parent of Ag-positive NORs was significantly higher in parents than controls. A significant difference in the size of the double-NOR variants [dNORs] was found. The mean maternal and paternal ages were significantly lower, with a significant increase in spontaneous abortions, for dNOR[+] couples compared with dNOR[-] couples
Sujets)
Adulte , Femelle , Humains , Nourrisson , Mâle , Adulte d'âge moyen , Avortement spontané/génétique , Études cas-témoins , Syndrome de Down/génétique , Nouveau-né , Caryotypage , Âge maternel , Non-disjonction génétique , Pedigree , GrossesseRésumé
A total of 3000 consecutive neonates delivered in a maternity hospital in Giza, Egypt, were subjected to full clinical and genetic evaluation. Social data included parental consanguinity and social class. The prevalence of malformations in the 3000 hospital live births and stillbirths was 3.17%. Malformed neonates [95] were classified into 13 groups according to the system affected using World Health Organization classification of congenital malformations. The most common anomalies were: central nervous system [29.5%], musculoskeletal system [20.0%] and genetic syndromes [13.7%]. Parental consanguinity was found in 31.79% of all cases and in 55.0% of malformed cases, thus illustrating the deleterious effects of consanguinity
Sujets)
Humains , Mâle , Femelle , Malformations/classification , Nouveau-né , Classe sociale , Méthodes épidémiologiques , MéthodesRésumé
A total of 660 patients referred to the genetics clinic, Medical Research Institute, Alexandria were assessed to determine the frequency of genetic disorders and the proportion of autosomal recessive disorders. It was found that 298 [45.2%] patients had genetic disorders, 100 [33.6%] of whom had an autosomal recessive disorder; these included 32 patients with metabolic defects, 18 with haemoglobinopathies and 50 with syndromes and single defects. The frequency of consanguinity among parents of patients with autosomal recessive disorders was high [60%, with 48% first cousins]. The average inbreeding coefficient was higher [0.03] than that reported for the Egyptian population in general [0.01]