Trisomy for distal segments of the long arm of chromosome 1

Clinical genetic analysis of distal trisomies 1q, based on the study of a t(1; 6) (q42.1; p24) family and the literature data, was performed. It was demonstrated that phenotypical manifestations of the trisomy are formed by nonspecific anomalies, due to imbalance as such, and by rather specific anomalies caused by triplication of a "critical segment". 1q42-1qter appeared to be such a segment for distal trisomy 1q.     

Trisomy for the distal third of the long arm of chromosome 19 in brother and sister

Summary Trisomy for the distal third of the long arm of chromosome 19 was observed in a 12-year-old boy and his 9-year-old sister. Both are affected by extremely severe statural and psychomotor retardation. The physical symptoms common to both are dwarfism, micro- and brachycephaly, antimongoloid slant of the eyes, hypertelorism, ptosis, short nose, short philtrum, poorly formed ears, short neck with excess skin, barrel-shaped thorax, diastasis of rectus muscles, kyphosis, sacral dimple, excess of digital arches, pedes valgi, laterally curved big toes, epilepsy and muscular hypotonia. The chromosomal anomaly was transmitted by the mother, who is the carrier of a translocation t(19;20)(19q133;20pter). In the pedigree, extending over four generations, among 30 pregnancies fathered or mothered by 5 carriers resulted in: 6 individuals with normal karyotype, 9 carriers, 2 confirmed and 2 presumptive unbalanced abnormal children, and 10 abortions.     

Reciprocal translocation between Y chromosome long arm euchromatin and the short arm of chromosome 1

A case with an apparently balanced reciprocal translocation between the long arm of the Y chromosome and the short arm of chromosome 1 t(Y;1)(q11.2;p34.3) is described. The translocation was found in a phenotypically normal male ascertained by infertility and presenting for intra-cytoplasmatic sperm injection treatment. Histological examination of testicular biopsies revealed spermatogenic failure. Chromosome painting with probes for chromosome 1 and for the euchromatic part of the Y chromsome confirmed the translocation of euchromatic Y chromosomal material onto the short arm of chromosome 1 and of a substantial part of the short arm of chromosome 1 onto the Y chromosome. Among the Y/autosome translocations, the rearrangements involving long arm euchromatin of the Y chromosome are relatively rare and mostly associated with infertility. Microdeletion screening at the azoospermia locus revealed no deletions, suggesting another mechanism causing infertility in this translocation carrier.     

Trisomy of the long arm of chromosome in a patient with primary myelofibrosis during blast crisis

The caryotype of a patient't leukemic cells with primary myelofibrosis being at the stage of blast crisis is described. In all cells examined a great submetacentric chromosome was detected which was formed by the duplication of the whole long arm of the first chromosome. The second chromosome of the first pair remained unchanged. Moreover, there was no sexual chromosome Y in seven metaphase plates. The significance of these and other changes of the first chromosome in the genesis of some malign diseases is discussed.     

Trisomy for the short arm of chromosome No. 10

To the authors knowledge there is a single previous report of confirmed trisomy for the short arm of chromosome No 10 (Hustinx et al., 1974). In this paper we present a further case of trisomy 10p, resulting from 3 : 1 segregation of maternal balanced translocation, t(3;10)(q;11), in a female infant aged 7 months and showing numerous somatic anomalies.     

Microdissection and microcloning of the long arm of human chromosome 7

DNA-fragments from the region of the long arm of human chromosme 7 to which the CF-locus has been mapped recently were isolated by microdissection and microcloning. We developed a new fixation procedure resulting in inserts of 1.0–7.0 kb in length with a mean value of 2.9 kb. Regional mapping of three clones on 7q was carried out by the use of different hybrid cell lines containing fragments of human chromosome 7.     

A refined physical map of the long arm of human chromosome 16

Mapping of 33 anonymous DNA probes and 12 genes to the long arm of chromosome 16 was achieved by the use of 14 mouse/human hybrid cell lines and the fragile site FRA16B. Two of the hybrid cell lines contained overlapping interstitial deletions in bands q21 and q22.1. The localization of the 12 genes has been refined. The breakpoints present in the hybrids, in conjunction with the fragile site, can potentially divide the long arm of chromosome 16 into 16 regions. However, this was reduced to 14 regions because in two instances there were no probes or genes that mapped between pairs of breakpoints.     

A genetic linkage map of the long arm of human chromosome 22

We have used a recombinant phage library enriched for chromosome 22 sequences to isolate and characterize eight anonymous DNA probes detecting restriction fragment length polymorphisms on this autosome. These were used in conjunction with eight previously reported loci, including the genes BCR, IGLV, and PDGFB, four anonymous DNA markers, and the P1 blood group antigen, to construct a linkage map for chromosome 22. The linkage group is surprisingly large, spanning 97 cM on the long arm of the chromosome. There are no large gaps in the map; the largest intermarker interval is 14 cM. Unlike several other chromosomes, little overall difference was observed for sex-specific recombination rates on chromosome 22. The availability of a genetic map will facilitate investigation of chromosome 22 rearrangements in such disorders as cat eye syndrome and DiGeorge syndrome, deletions in acoustic neuroma and meningioma, and translocations in Ewing sarcoma. This defined set of linked markers will also permit testing chromosome 22 for the presence of particular disease genes by family studies and should immediately support more precise mapping and identification of flanking markers for NF2, the defective gene causing bilateral acoustic neurofibromatosis.     

A centromere-based linkage group on the long arm of human chromosome 17

A genetic linkage group on the long arm of chromosome 17 is reported. A maximum likelihood of theta = 0.20 between the centromere-based locus D17Z1 and COL1A1 has been found, as well as a theta = 0.10 between COL1A1 and GH1. The most likely order of the three loci is D17Z1-COL1A1-GH1.     

Structure of the pericentric long arm region of the human Y chromosome.

We have analysed the sequence organization of the DNA in the pericentric region of the long arm of the human Y chromosome. The structures of one cosmid and three yeast artificial chromosome clones were determined. The region consists of a mosaic of the known 5, 48 and 68 base-pair tandemly repeated sequences and at least five novel repeated sequence families. A long range-map of approximately 3.5 x 10(6) base-pairs of genomic DNA was constructed that placed the clones between about 500 x 10(3) and 850 x 10(3) base-pairs from the long arm edge of the centromeric alphoid DNA array.     

Fragile site long arm chromosome 16

Summary A fragile site at the long arms (q21) of chromosome 16 was found in two persons, each of whom became the parent of a child with a de novo structural chromosome abnormality—a balanced autosomal translocation and an autosomal deletion. The question of an increased risk of structural chromosome abnormalities in the offspring of persons with fragile site long arm 16 is discussed.     

Repeated DNA sequences in the distal long arm of the human X chromosome

Summary Two DNA probes from within a single large insert from a recombinant phage-DNA library that was constructed from flow-sorted chromosomes enriched for the human X chromosome were shown to hybridize with repeated X-specific and autosomal DNA sequences. The X-chromosomal repeated sequences were assigned to the distal long arm of the X chromosome by both hybrid mapping and in situ hybridization. Fine mapping places these repeats in a region of Xq28 between DX13 (DXS15, in distal Xq28) and factor VIII (F8C, in proximal Xq28). The location of the X-specific repeats makes them potentially useful for future investigations of discases mapping to the distal long arm of the X chromosome, such as the fragile X syndrome.     

Cosmid linking clones localized to the long arm of human chromosome 11.

Molecular probes that contain DNA flanking CpG-rich restriction sites are extremely valuable in the construction of physical maps of chromosomes and in the identification of genes associated with hypomethylated HTF (HpaII tiny fragment) islands. We describe a new approach to the isolation and characterization of linking clones in arrayed chromosome-specific cosmid libraries through the large-scale semiautomated restriction mapping of cosmid clones. We utilized a cosmid library representing human chromosome 11q12-11qter and carried out automated restriction enzyme analysis, followed by regional localization to chromosome 11q using high-resolution in situ suppression hybridization. Using this approach, 165 cosmid linking clones containing one or more NotI, BssHII, SfiI, or SacII sites were identified among 960 chromosome-specific cosmids. Furthermore, this analysis allowed clones containing a single site to be distinguished from those containing clusters of two or more rare sites. This analysis demonstrated that more than 75% of cosmids containing a rare restriction site also contained a second rare restriction site, suggesting a high degree of CpG-rich restriction site clustering. Thirty chromosome 11q-specific cosmids containing rare CpG-rich restriction sites were regionally localized by high-resolution fluorescence in situ suppression hybridization, demonstrating that all of the CpG-rich sites detected by this method were located in bands 11q13 and 11q23. In addition, the distribution of (CA)n repetitive sequences was determined by hybridization of the arrayed cosmid library with oligonucleotide probes, confirming a random distribution of microsatellites among CpG-rich cosmid clones. This set of reagent cosmid clones will be useful for physical linking of large restriction fragments detected by pulsed-field gel electrophoresis and will provide a new and highly efficient approach to the construction of a physical map of human chromosome 11q.     

Homozygous duplication on long arm of chromosome pair no. 1

Summary In members of a family it was found, that the long arms from one or both chromosomes A₁ are lengthened. The elongation of the chromosomes was caused by duplication of the paracentric region as shown by Giemsa banding pattern.

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Zusammenfassung Bei mehreren Mitgliedern einer Familie wurde eine Verlängerung der langen Arme eines oder beider Chromosomen A₁ beobachtet. Dem Giemsa-Bändermuster zufolge dürfte eine Duplikation des zentromerennahen Abschnittes vorliegen.

     

Deletion mapping of H-Y antigen to the long arm of the human Y chromosome

A gene encoding or controlling the expression of the H-Y transplantation antigen was previously mapped to the human Y chromosome. We now report the sublocalization of this gene on the long arm of the human Y chromosome. Eight patients with Y-chromosomal abnormalities were examined with a series of existing and new DNA markers for the Y chromosome. The resulting deletion map was correlated with H-Y antigen expression. We conclude that the H-Y antigen gene maps to a portion of deletion interval 6 that is identified by specific DNA markers.     

Assignment of the human gamma-glutamyl transferase gene to the long arm of chromosome 22

Summary We have determined the chromosomal location of the human gene for gamma-glutamyltransferase (GGT). This study was done by in situ hybridization of human metaphase spreads with a rat cDNA probe specific for this enzyme and constructed from two clones previously characterized in our laboratory. The final construct had a 1.6-kb-long insert covering 92% of the coding sequence for GGT. The new insert was also freed of any GC tails introduced for the cDNA cloning, because we observed that these sequences were responsible for a high background. Using this probe for the analysis of 136 human metaphase spreads, we observed a strong specific signal on chromosome 22 at the interface of q111-112 and a minor peak in q131. Thus GGT might represent a new marker for the study of certain diseases which have chromosomal abnormalities at these loci.     

Assignment of the TCP1 locus to the long arm of human chromosome 6 by in situ hybridization

TCP1, the human homolog of the Tcp-1 locus in the mouse, which is part of the murine t complex and codes for an abundant testicular germ-cell protein, has been mapped within the human genome by in situ hybridization. Using a cDNA probe for TCP1, pB1.4 hum, we assigned TCP1 to human chromosome region 6q23----qter, with the most likely localization being 6q25----q27.