ABSTRACT
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
Subject(s)
Adult , Female , Humans , Infant , Male , Middle Aged , Abortion, Spontaneous/genetics , Case-Control Studies , Down Syndrome/genetics , Infant, Newborn , Karyotyping , Maternal Age , Nondisjunction, Genetic , Pedigree , PregnancyABSTRACT
A diagnostic evaluation of craniofacial anomalies, either isolated or as part of a genetic syndrome was conducted on 25 patients [8 females, 17 males], age range 2 months to 47 years. Complete genetic examination, pedigree analysis, anthropometric measurements and radiological studies were carried out. Cytogenetic studies included fluorescence in situ hybridization [FISH] when indicated. In all, 15 patients had chromosomal abnormalities. Five patients had unbalanced chromosome rearrangements and six had chromosome markers. Three patients were FISH-positive for William syndrome and one was positive for Prader-Willi syndrome. Ten patients had monogenic disorders. Five were diagnosed as craniosynostosis syndromes. We conclude that minor features are useful for making a diagnosis of congenital anomalies
Subject(s)
Humans , Male , Female , In Situ Hybridization, Fluorescence , Chromosome Aberrations , Craniofacial Abnormalities/genetics , Genetic Markers , Williams Syndrome , Prader-Willi SyndromeABSTRACT
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]