Human (Homo sapiens) and chimpanzee (Pan troglodytes) share similar ancestral centromeric alpha satellite DNA sequences but other fractions of heterochromatin differ considerably.

The euchromatic regions of chimpanzee (Pan troglodytes) genome share approximately 98% sequence similarity with the human (Homo sapiens), while the heterochromatic regions display considerable divergence. Positive heterochromatic regions revealed by the CBG-technique are confined to pericentromeric areas in humans, while in chimpanzees, these regions are pericentromeric, telomeric, and intercalary. When human chromosomes are digested with restriction endonuclease AluI and stained by Giemsa (AluI/Giemsa), positive heterochromatin is detected only in the pericentromeric regions, while in chimpanzee, telomeric, pericentromeric, and in some chromosomes both telomeric and centromeric, regions are positive.

Counterstained enhancement of TaqI resistant sites after distamycin A/diamidinophenylindole treatment.

Numerous selective and differential staining techniques have been used to investigate the hierarchical organisation of the human genome. This investigation demonstrates the unique characteristics that are produced on fixed human chromosomes when sequential procedures involving restriction endonuclease TaqI. distamycin A (DA) and 4',6-diamidino-2-phenylindole (DAPI) are employed.

Arytenoid adduction and type I thyroplasty in the treatment of aphonia.

Arytenoid adduction is a procedure used to medialize the paralyzed vocal fold, closing the posterior glottis. Isshiki type I thyroplasty allows medialization of the anterior membranous vocal fold. Using the arytenoid adduction, in combination with Isshiki type I thyroplasty as needed, five patients were treated for aphonia.

Monozygotic twinning in a female with triple X[47,XXX].

We report a successful twin pregnancy in a woman with secondary amenorrhea who is genotypically 47,XXX. Cytogenetic markers suggested that they are apparently monozygotic twins.

Centromeric and telomeric repeats are stable in nonagenarians as revealed by the double hybridization fluorescent in situ technique.

We report a simple method for simultaneous identification of centromeric and telomeric repeat sequences of human chromosomes. Employing this technique, we investigated the stability of centromeres and telomeres in individuals over 90 years of age and compared them with younger controls (< 40 years). Our findings suggest that centromeric and telomeric repeats remain apparently stable in nonagenarians.

Direct visualization of the transposed ABL gene in a duplicated masked Ph chromosome.

In a small percentage of cases of chronic myelogenous leukemia (CML), where the Ph chromosome is masked because of highly complex translocations and sub-microscopic rearrangements, precise identification of chromosomal aberrations by routine banding techniques has been difficult. We report on a new case of CML in which a single copy of a masked Ph chromosome was duplicated during blast crisis, i.e.

Chromosomal anomalies in 1,000 children referred with suspected genetic disorders.

One thousand children ranging from newborns to 13 years of age with a variety of clinical disorders were referred to us to investigate the possible presence of chromosomal abnormalities. Various types of chromosomal anomalies were found in 166 children (16.6%), which is significantly (p < 0.

Molecular characterization of a complex translocation in a newborn infant.

A newborn infant was referred because of low-set ears, mild downward slant of the palpebral fissures, micrognathia with high-arched palate, a flat midface, small mouth, and thin upper lip with cupid bow configuration. To some extent her cry resembled that associated with cri du chat syndrome. Cytogenetic findings with G- and Q-banding alone failed to characterize precisely the complex translocations.

Molecular characterization of the secondary constriction region (qh) of human chromosome 9 with pericentric inversion.

Pericentric inversion of the secondary constriction region (qh) of human chromosome 9 is a frequent occurrence. This structural alteration is regarded as a normal familial variant, termed heteromorphism, and is inherited in a Mendelian fashion without any apparent phenotypic consequences. We characterized the qh region of chromosome 9 from five individuals using a series of molecular cytogenetic techniques.

Disappearance of a highly unusual clone, 46,XY,del(7)(p12),t(9;22)(q34;q11) in chronic myeloid leukemia after treatment with recombinant interferon and cytosine arabinoside.

A patient with the typical features of the stable phase of chronic myeloid leukemia (CML) displayed two karyotypically related subclones. In addition to the t(9;22), cells from one clone contained a deletion of the short arm of chromosome 7, del(7)(p12), [46,XY,del(7)(p12),t(9;22)(q34;q11)]; the other contained only the standard translocation [46,XY,t(9;22)(q34;q11)]. Cells with a deletion of the short arm of chromosome 7 at band p12 as the only additional abnormality have not been observed previously in CML.

Molecular characterization of the smallest secondary constriction region (qh) of human chromosome 16.

We report the smallest secondary constriction region (h) in human chromosome 16. The cytochemical, cytogenetic, and molecular techniques revealed the complex heterogeneity of heterochromatin observed in this region. The heteromorphisms can be found due to the variation in centromeric (c) region alone or in combination with the h region.

Detection of the heteromorphic spectrum of heterochromatin in the human genome by in situ digestion using restriction endonuclease AluI.

A battery of selective banding techniques has been utilized to identify the heteromorphic markers in the human genome. The recent addition of the AluI/Giemsa (G)-technique has helped not only in identifying the variable sites, but in characterizing their heteromorphic spectra. In the present investigation, we classified the pericentromeric heterochromatin by the AluI/G-technique by its size and position using 50 normal individuals and suggested the potential uses of this banding technique over earlier methods.

The interstitial deletion of bands q33-35 of long arm of chromosome 7: a review with a new case report.

Interstitial or terminal deletion resulting in partial monosomy of various segments of the long arm of chromosome 7 was first recorded over two decades ago. Since then, a number of reports have correlated the severity of clinical manifestations with the length of the deletion involved. However, difficulty remains in defining a so-called "distinct syndrome".

Pericentric inversion of chromosome 7 (inv(7) (p22q11.2)) and ring chromosome 8 (r(8) (p23q24.3)) in a girl with minor anomalies.

A 13 year old girl was referred with congenital microcephaly, developmental delay, a prominent nose, highly arched palate, and an apparently low set left ear. She was found to have a pericentric inversion of one chromosome 7 and a ring chromosome 8, 46,XX,inv(7) (pter----p22::q11.23----p22::q11.

An apparent balanced translocation [t(9;11)(p21.2;p14.2)] in a neonate with dysmorphic features.

The role of so called balanced translocations in human morphogenesis remains puzzling. An eleven month old hispanic female was referred for neurological evaluation. The major dysmorphic features include: epicanthal folds, flat nasal bridge, small mouth, micrognathia, low set ears and cleft-palate.

The T cell receptor gene and its association with human diseases.

The genetic organization and protein structure of the T cell receptor (TCR)/CD3 complex are currently under investigation, and recent work has provided information about its assembly, expression and function. This article reviews what is currently known about the structure and assembly of the TCR/CD3 complex. The TCR chains are members of the immunoglobulin gene superfamily and are generated by combinatorial associations of V, J, D, and C genes.

Heteromorphisms of pericentromeric heterochromatin of chromosome 19.

The pericentromeric heterochromatin of chromosome 19 exhibits considerable variation even by the G-banding technique. Nevertheless, the C-banding technique has been universally employed to investigate pericentromeric hetromorphisms. We demonstrate that optimal expression of the pericentromeric region can be achieved by using the AluI/G technique.

Clonal expansion after bone marrow transplantation in a patient with chronic myelogenous leukemia.

A patient with chronic myelogenous leukemia (CML) having the standard [t(9;22), Ph] translocation is presented where the Philadelphia (Ph) chromosome disappeared following bone marrow transplantation (BMT). The Ph chromosome reappeared in host cells after one year of stable hematologic remission. Three additional cell lines, all possessing the Ph chromosome with other abnormalities were consistently present in her marrow cells.