1/159. Increased sister chromatid exchange in bone marrow and blood cells from Bloom's syndrome.Bone-marrow cells from a patient with Bloom's syndrome cultured for 48 h in the presence of BudR exhibited a striking increase in the number of sister chromatid exchanges (SCEs) in comparison to that in the marrow cells of a patient with treated polycythemia vera (PV). Thus, it appears that an increased incidence of SCE in Bloom's syndrome occurs in various differentiated types of cells, not just blood lymphocytes, and constitutes the syndrome's most characteristic cytogenetic feature. In contrast, the incidence of SCE was not increased in marrow cells and lymphocytes of the particular PV patient studied here, whose cells did exhibit increased numbers of chromatid and chromosome gaps and breaks, presumably as result of the patient's earlier treatment. An increased frequency of SCE was demonstrated in Bloom's syndrome lymphocytes using both a technique based on BudR incorporation and one based on labeling with tritated deoxycytidine. This observation constitutes evidence against the increase of SCE being due to an unusual reaction to BudR. By conventional cytogenetic techniques, chromosome instability, including chromatid and chromosome breaks, but no homologous chromatid interchanges were also recognized in Bloom's syndrome bone-marrow cells incubated in vitro (without BudR) for either 1.k or 16 h. This observation points to the existence of chromosome instability in vivo.- - - - - - - - - - ranking = 1keywords = chromosome (Clic here for more details about this article) |
2/159. Exclusion of chromosome 9 helps to identify mild variants of acromesomelic dysplasia Maroteaux type.Acromesomelic dysplasia Maroteaux type (AMDM) is an autosomal recessive disorder belonging to the group of acromesomelic dysplasias. AMDM is characterised by severe dwarfism with shortening of the middle and distal segments of the limbs. An AMDM gene has recently been mapped to human chromosome 9p13-q12 by homozygosity mapping in four consanguineous families. Here, we show linkage of the disease gene to chromosome 9p13-q12 in four of five consanguineous AMDM families and its exclusion in a fifth family with two children affected with a mild form of the disease. This study suggests that genetic heterogeneity accounts for the variable clinical and radiological severity of AMDM.- - - - - - - - - - ranking = 1.5keywords = chromosome (Clic here for more details about this article) |
3/159. Campomelic dwarfism.The campomelic syndrome is a short-limb, usually fatal, neonatal dwarfism. It is characterized by bowed lower limbs, especially the tibia, usually associated with a cutaneous dimple over the anterior skin. There is delayed calcification of the epiphyses and delayed mineralization of the spine and pelvis. The cartilages of the tracheobronchial tree are hypoplastic, contributing to death from respiratory problems. Other associated abnormalities are unusual appearing facies, cleft palate, absent olfactory nerves and talipes equinovarus. Less commonly seen are cardiac, renal and brain anomalies.- - - - - - - - - - ranking = 0.0036248433492153keywords = ring (Clic here for more details about this article) |
4/159. Exclusion of chromosome 15q21.1 in autosomal-recessive weill-marchesani syndrome in an inbred Lebanese family.We report an inbred family where 3 siblings had short stature, brachydactyly, limitation of joint movements, microspherophakia, luxated lenses, glaucoma, and heart malformations. parents of the affected siblings were relatively short, but did not have any of the other features present in their siblings. Those clinical features are consistent with the Weill Marchesani syndrome (MIM 277600). Both autosomal-recessive and autosomal-dominant pedigrees have been reported, with a possible linkage to chromosome 15q21.1 in the latter. Linkage analysis at 15q21.1 in this Lebanese family allowed us to exclude the role of this region in the etiology of the syndrome. Speculations regarding the pathogenesis of the disorder are discussed.- - - - - - - - - - ranking = 1.25keywords = chromosome (Clic here for more details about this article) |
5/159. Isochromosome consisting of terminal short arm and proximal long arm X in a girl with short stature.A 16-year-old girl with short stature, short neck, shield chest, and cubitus valgus was studied. FISH analyses of her structurally altered x chromosome showed a der(X)- (wcpX ,TelXp/Yp ,SHOX ,STS ,KAL-, 37A12-,DXZ1 ,XIST ,97L7 ,300O13-,404F- 18-,417G15-,404F18-,140A-,TelXq/Yq-). These results, together with the high-resolution banding analysis, indicated her karyotype to be 46,X,der(X)(Xpter-->Xp22.3::Xq22.3--> cen-->Xq22.3::Xp22.3-->Xpter). The der(X) was an isochromosome, consisting of duplicated terminal short arms and duplicated proximal long arms. This in turn suggested that the chromosome was formed through pericentric inversion of an x chromosome, followed by isochromosome formation through sister chromatid exchange at Xp, close to the centromere. Replication R-banding analysis showed that the abnormal x chromosome was late replicating. Analysis of digestion patterns with a methylation-sensitive restriction endonuclease of the phosphoglycerate kinase 1 gene, located in Xq13.3, indicated that its inactivation patterns were completely skewed.- - - - - - - - - - ranking = 2.5keywords = chromosome (Clic here for more details about this article) |
6/159. Brachytelephalangic dwarfism due to the loss of ARSE and SHOX genes resulting from an X;Y translocation.Here we report an 8-year-old male patient who had mesomelic shortening of forearms and legs, brachytelephalangia and ichthyotic skin lesions. Chromosomal analysis showed an X;Y translocation involving the short arm of the x chromosome (Xp). fluorescence in situ hybridization (FISH) and molecular studies localized the breakpoints on Xp22.3 in the immediate vicinity of the KAL gene demonstrating deletions of steroid sulfatase (STS), arylsulfatase E (ARSE), and short stature homeo box (SHOX) genes. It was suspected that the patient was suffering from chondrodysplasia punctata because of a loss of the arylsulfatase E (ARSE) gene. However, no stippled epiphyses were to be seen in the neonatal radiograph. Interestingly, this patient is the first case with a proven loss of the ARSE gene without chondrodysplasia punctata, assuming that chondrodysplasia punctata is not an obligatory sign of ARSE gene loss. Brachytelephalangia was the only result of ARSE gene deletion in this case. The patient's mother also had dwarfism and showed Madelung deformity of the forearms. She was detected as a carrier of the same aberrant x chromosome. The male patient did not show Madelung deformity, demonstrating that Lerri-Weill syndrome phenotype may be still incomplete in children with SHOX gene deletion. The wide clinical spectrum in the male and the Leri-Weill phenotype in his mother are the results of both a deletion involving several sulfatase genes in Xp22.3 and the SHOX gene located in the pseudoautosomal region. Nevertheless, there is no explanation for the absence of chondrodysplasia punctata despite the total loss of the ARSE gene. Further studies are necessary to investigate genotype/phenotype correlation in cases with translocations or microdeletions on Xp22.3, including the ARSE and the SHOX gene loci.- - - - - - - - - - ranking = 0.50362484334922keywords = chromosome, ring (Clic here for more details about this article) |
7/159. Early-onset liver disease complicated with acute liver failure in alstrom syndrome.We report a case of alstrom syndrome with evidence of extensive hepatic disease diagnosed at five years of age, who subsequently developed acute liver failure and died at eight years of age. Such a case, with the patient dying before the age of ten, has not been described before. The biochemical findings during our patient's liver failure raised the question of a possible mitochondrial function defect in this syndrome. Further investigation of this possibility is needed.- - - - - - - - - - ranking = 0.0036248433492153keywords = ring (Clic here for more details about this article) |
8/159. trisomy 8 syndrome.trisomy 8 syndrome, with or without mosaicism, is characterized by the following clinical signs and symptoms: mental retardation, deformed skull, prominent forehad, high-arched palate, low-set and/or dysplastic ears, long and slender trunk, reduced joint mobility, and deep plantar furrows. The deep furrow or longitudinal crease of the sole may be pathognomonic for the syndrome. It should be noted that it has been seen in other rare syndromes. It is recommended that a child with mental retardation and associated multiple anomalies should be subjected to a cytogenetic study in order to define the incidence of this syndrome. Differnetial diagnosis should include: Fong's syndrome, arthrogryposis and otopalato-digital syndrome. It is interesting to note that there seem to be individuals who have had no physical abnormalities and have been identified during an evaluation for repeated abortions. The above described case of trisomy 8 mosaicism was seen and treated for many years by many different specialists without an accurate diagnosis.- - - - - - - - - - ranking = 0.0036248433492153keywords = ring (Clic here for more details about this article) |
9/159. Hallermann-Streiff syndrome and progeria.Reported is an atypical, severe case of Hallermann-Streiff syndrome combined with progeria, bilateral microphthalmus, cataracts, and normal chromosome count. A plea is made for study into the teratology of abnormal chemical, metabolic, and other forces that attack the early stages of the development of the human fetus and produce multiple anomalies.- - - - - - - - - - ranking = 0.25keywords = chromosome (Clic here for more details about this article) |
10/159. prenatal diagnosis of kyphomelic dysplasia.Kyphomelic dysplasia (KD) is a rare autosomal recessive entity characterized by disproportionate dwarfism with shortening and bowing of the limbs, narrow chest, 11 ribs and metaphyseal flaring. Mental development is generally normal. We report the in utero ultrasound appearances and post-mortem radiographic findings of a 22-week-old male fetus suggestive of KD. A review of 19 previously reported patients with KD is also presented.- - - - - - - - - - ranking = 0.0036248433492153keywords = ring (Clic here for more details about this article) |
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