Disease associated balanced chromosome rearrangements-report on 12 cases

The population frequency of familial disease balanced chromosome rearrangement with discordance for an abnormal phenotype is unknown. De novo balanced chromosome rearrangements are present in approximately 1:2000 newborn. The increased frequency of associated diseases may be due to truncation, inactivation or overexpression of specific genes. Uniparental disomy [UPD] has also been implicated. We report on 12 cases with apparently balanced chromosome rearrangements with abnormal phenotypes, 8 familial [5 families] and 4 de novo. Maternal inheritance accounted for 7/8 cases. The rearrangements included reciprocal translations in 8 cases, Robertsonian translocation in 2 cases and pericentric inversion in 2 cases. Apparently balanced rearrangements in general, represent an interpretational and counseling dilemma when detected in cases with abnormal phenotypes and/or mental retardation

Phenotypic variability in patients with isodicentric Y [p11.3]. Aclinical, cytogenetic and molecular study

Isodicentric [idic] chromosomes are the most common Y structural abnormalities and their influence on gonadal and somatic development is extremely variable. The prediction of their phenotypic consequences is often difficult because of the variety of genomic sequences concerned by duplications and deletions, and the variable degrees of mosaicism, 45, X cell line in particular, in various tissues. This study was conducted to provide more information on patients with idic [Yq] allowing a better phenotype-karyotype correlation and understanding the sexual differentiation in these patients. The study included 14 patients referred to the out patient clinic of the Human Genetics Department, Medical Research Institute, University of Alexandria. The reason for referral was genital ambiguity [8 patients], short stature with variable Turner stigmata [4 patients] and primary amenorrhea with normal height [2 patients]. All patients were subjected to clinical examination and chromosome analysis by GTG and CTG-banding techniques. Fluorescence in situ hybridization [FISH] and polymerase chain reaction [PCR] were done to determine the structure of the marker chromosomes detected by conventional methods. Chromosome analysis revealed a 45, X/46, X, idic [Y] [p11.3] in ten patients with variable degree of mosaicism, non mosaic 46, X, idic [Y] [p11.3] in two patients and a predominant 46, XX cell line along with 47, XX, idic [Y] [p11.3] cell line in two other patients .While the patients with an idic [Yq] described in this report were phenotypically different, all are considered as being at increased risk for gonadoblastoma. The great phenotypic variations seen in patients with an isodicentric Y chromosome greatly limit the genotype - phenotype correlation

biochemical and genotoxic effects of occupational exposure to vinyl chloride monoer

This study aimed to investigate the biochemical and genotoxic effects of the occupational exposure to vinyl chloride monomer [VCM]. The study included 84 workers occupationally-exposed to VCM, including 54 working in the Petrochemical Company and 30 working in El-Masria Company, in addition to 20 subjects as a control group. The biochemical assessment of the occupationally-exposed group involved a determination of glutathione [GSH] content in whole blood, erythrocyte glutathione peroxidase [GPx] and glutathione S-transferase [GST]. Twenty workers showed an elevation in these biochemical parameters. They were subjected to cytogenetic investigations including blood cultures for sister chromatid exchange [SCE] evaluation and micronucleus [MN] assay. A cytogenetic evaluation was performed to six of the control group using both SCE evaluation and MN assay. The statistical analysis of variance between groups [one-way ANOVA] revealed a significant decrease in GSH and GPx levels in the blood of workers when compared with the control group and a significant increase in the level of GST in workers when compared with the control group. The mean SCE/cell for the exposed workers was higher than that of the control, the difference was statistically nonsignificant. The mean MN/500 cytokinesis blocked binucleated cells was higher in the occupationally-exposed workers as compared the control group, the difference was statistically significant

Micronucleus assay in patients with lung cancer, chronic obstructive pulmonary disease and non-smoker control

This study included 96 male subjects; 40 patients with lung cancer, 36 patients with chronic obstructive pulmonary disease [COPD] and 20 control subjects. 25% of cases with lung cancer and 86.1% of cases with COPD had micronucleus [MN] frequency ranging <5-<15 MN/500 cytokinesis blocked [CB] binucleated cells compared with 100% in the control group. 40% of cases with lung cancer and 13.9% of cases with COPD had 15-20 MN/500 CB binucleated cells. 35% of cases with lung cancer had 20-25 MN/500 CB binucleated cells. These differences were statistically significant. In the lung cancer group, the mean MN/500 CB binucleated cells was 18.4 +/- 4.2, in the group with COPD, it was 8.3 +/- 4.1 with 8 patients having MN in the cancer range, i.e. 12-17. The mean MN/500 CB binucleated cells in the control group was 5.4 +/- 2.5. These differences were statistically significant. All cases with lung cancer and 63.9% of cases with COPD had a mean MN frequency greater than 95% CI of the mean MN frequency for the control group. Applying logistic regression analysis for the effect of risk factors revealed that lung cancer patients, who were current or ex- smokers, had significantly higher MN frequencies than patients with COPD

C-band heteromorphism in lung cancer patients

This study was conducted to investigate the intra-pair asymmetry, inversions and deviation in the size of the C-band region of chromosomes 1, 9 and 16 in 39 patients with lung cancer as compared with a group of 29 healthy subjects as controls. The size heteromorphism was evaluated using 16p as a reference. Heteromorphism between homologous chromosomes was considered when there was an intra- pair difference of one or more levels. Inversions whether partial [more than 1/4 of the C-band located on the short arm] or total were recorded. There was no significant difference in heterochromatin size between patients and controls. Comparing the symmetry and heteromorphic pattern in chromosomes 1, 9 and 16 revealed that heteromorphism was more frequent in lung cancer patients compared with the control groups. Heteromorphism of chromosome No. 9 was present in 51.28% in the lung cancer patients as compared with 34.48% of the control, the difference was statistically insignificant. Heteromorphism of chromosome No. 16 was present in 23.08% of the lung cancer patients as compared with 13.79% of the control group, but the difference was statistically insignificant. The frequency of localization variants was higher in the lung cancer patients than the control. The frequency of inversions in chromosome 9 was 5.13% in the group with lung cancer as compared with 1.73% in the control group, the differences were statistically insignificant

Chromosome damage in passive smoker female

Current epidemiological data associates passive smoking with health hazards which not only affects the passive smoker but also affects the offsprings of passive smoker females. To determine the effect of cigarette smoke on the chromosomes of passive smoker females who were still in the childbearing age, the micronucleus [MN] frequency in 20 passive smoker females [spouse smoker] who had been exposed to cigarette smoke for at least 5 years was compared to the MN frequency in 20 control subjects [females with non-smoking spouse] all in the age group 31-39 years. The MN frequency among passive smoker female group ranged from 16-27 MN/500 cytokinesis blocked [CB] binucleated cell, with a mean of 21.1 +/- 3.7, while the MN frequency among the control group ranged from 3-11 MN/500 CB binucleated cell, with a mean of 8 +/- 1.7. The difference is statistically significant [t=14.2, p<0.01]. Applying the correlation coefficient test between age and MN frequency, a weak positive though non significant correlation was found between age and MN frequency in the passive smoker female group [R=0.11, p=0.630] while an intermediate positive but still non significant correlation was found between age and MN frequency in the control [R=0.26, p=0.27]. There was a positive correlation between the duration of exposure to cigarette smoke and the MN frequency, but this was statistically non significant [R=0.33, p=0.125]. The results emphasize that mothers especially in the childbearing age should not be exposed to cigarette smoke to avoid its deleterious effects on their health thus preventing any harmful effect the smoke can have on their offsprings

Relationship between head circumference and psychomotor development in down syndrome

In the present study, the head circumference of 44 Down syndrome patients as well as 80 control subjects was measured and plotted on the Egyptian control chart. Assessment of the psychomotor skills of Down syndrome patients and the control group was performed using the Denver development screening test. The developmental quotient was calculated. The head circumference of DS patients was significantly lower than the control group. The head circumference of Down syndrome patients showed deviation from the normal population range with advancing age. The gross motor sector showed the most severe delay in all ages studied. The language sector showed a decline with age and was the most retarded domain in the older Down syndrome patients. An intermediate +ve, though insignificant correlation, was found between the head circumference and the developmental quotient in Down syndrome patients aged 6 months - 1.5 years, while a strong +ve correlation between the head circumference and the developmental quotient was found in Down syndrome patients aged 1.5 - 2.5 years, implying that the head circumference plays a role in the psychomotor retardation of Down syndrome patients

Heteromorphisms of Ag stained nucleolus organizer region [NORs] in acrocentric chromosomes of Egyptians

The nucleolar organizer region [NORs] of the acrocentric chromosomes of 80 normal Egyptians [40 males, 40 females] were studied using the Ag-staining technique [NSG]. The Ag-staining of NORs varied from one individual to the other, yet a consistent pattern of Ag +ve NORs was present in each individual. The modal number of Ag +ve NORs per cell ranged from 6 to 10. The average modal number of Ag +ve NORs per individual was 7.65. No sex difference was observed in the sample studied. The size distribution of silver +ve NORs revealed that very large NORs occurred with a frequency of 7%. The frequency of large NORs was 24.13%, medium sized NORs was 30.75%, small sized NORs was 14.62%, while the frequency of absent NORs was 23.5%. A racial difference in the expression as well as in the size of NORs is proposed. Only one individual [1.25%] was identified as possessing a double NORs [dNORs]