Probing the human genome in search for a new 3q syndrome.

We report a case of partial trisomy 3q syndrome which could not be clinically identified as a distinct entity. The major clinical findings include: psychomotor delay with behavioral problems, coarse facial features, frontal bossing, bushy eyebrows, prominent ears, a small upturned nose and a history of repaired inguinal hernia. There was an additional material on chromosome 4, which could easily be matched with bands 18q21.

Evolutionary divergence of the oncogenes GLI, HST and INT2.

Almost a quarter of a century ago, the banding patterns of human and other higher primate chromosomes were compared, creating a barrage of speculation. Consequently, a number of approaches have been used to understand human descent. Chromosome modifications are believed to be important in the origin of species, and pericentric inversions account for the majority of evolutionary chromosomal alterations seen in Hominoidea.

Direct insertion of euchromatic material from chromosome Y in the X-chromosome in hypogonadotropic hypogonadisms with Crohn's disease.

The relationship between chromosomal abnormalities and Crohn's disease has not been established. Crohn's disease is associated with inflammation of the bowel, severe abdominal pain and chronic diarrhea. Its etiology is not known at present.

Highly complex chromosomal aberrations in bone marrow of a patient with metastatic prostate neoplasm.

Prostate cancer is the single most common malignancy among men in North America. Nevertheless, cytogenetic evaluation of bone marrow in patients with metastatic prostate neoplasm has been rare and, to date, only five such patients have been reported. We report an additional case where chromosomal abnormalities of a bizarre nature were found in the bone marrow.

Brief communication: comparative mapping of the human estrogen receptor (ESR) and the Kallmann (KAL) regions to the chromosomes of the great apes.

Human and great ape chromosomes display significant concordance by molecular and cytogenetic techniques, which may reflect their common origin. Nevertheless, chromosomal banding techniques did not reflect the syntenic homology at the DNA level, which created controversy and debate. The recent availability of the unique sequence loci-specific human estrogen receptor (ESR) (bq25.

Marker chromosomes in fetal loss.

The clinical significance of marker chromosomes has remained obscure especially when diagnosed prenatally. Some carriers have terminated their pregnancies. Extensive attempts have been made to characterize these chromosomes whose origin is frequently difficult to ascertain.

Rapid denaturation improves chromosome morphology and permits multiple hybridizations during fluorescence in situ hybridization.

Denaturation of chromosomal DNA for fluorescence in situ hybridization (FISH) is an essential step in a procedure associated with a number of variables. In our experience, shorter denaturation time in 70% formamide/2 x SSC at 72 C provides sufficient denaturation, where the hydrogen bonds are broken between the purines and pyrimidines of the double helix. This shortened exposure improves retention of morphology of human chromosomes from lymphocytes, aminocytes, fibroblasts and bone marrow, and allows the same metaphases to be denatured repeatedly and rehybridized with different probes.

Paracentric inversion involving the long arm of chromosome 9 resulting in deletion of abl gene.

We report on a new chromosomal finding in a newborn male with hypertelorism, apparently low-set malformed ears with patent canal, micrognathia with narrow high-arched palate, bilateral webbing of neck with low posterior hairline, widely spaced nipples, and complex heart anomalies. Initially, what appeared to be a simple paracentric inversion of the long arm of chromosome 9, that is, 46,XY, inv(9)(q31q34) by routine GTG-banding technique was later determined to be a paracentric inversion with deletion of the band 9q34.1 by FISH technique using an abl unique sequence DNA probe.

Characterization of an isodicentric Y-chromosome for the long arm in a newborn with mixed gonadal dysgenesis.

A newborn infant was referred for evaluation because of ambiguous genitalia. Examination of the genitalia revealed a hypospadiac phallus measuring 1.5 cm in length with chordee.

A de novo interstitial deletion of chromosome 15 band q25 as revealed by FISH-technique.

We report a new chromosomal finding in a 20 month-old girl. The minor clinical features included: moderate mental retardation, microcephaly, mild hypotonia and hypertelorism. Initially, what appeared to be a terminal deletion of the long arm of one chromosome 15 [15q26-->qter] was determined to be an interstitial deletion involving band 15q25 as revealed by FISH-technique, showing the presence of intact telomeric hybridization signals.

Breakpoints in alpha, beta, and satellite III DNA sequences of chromosome 9 result in a variety of pericentric inversions.

Human chromosome 9 with a pericentric inversion involving the qh region is considered normal. It has probably evolved through breakage and reunion and is retained through mendelian inheritance without any apparent phenotypic consequences. Fluorescent in situ hybridisation (FISH) technique using alpha, beta, and satellite III DNA probes showed that the breakpoints are variable and can be localised in the alpha or in the satellite III and beta DNA regions or both.

Retrieval of aneuploidy by FISH-technique in a case with 46,XX/47,XXX/47,XX,+8.

We report on a 46 year old female with a new chromosomal finding [46,XX/47,XXX/47,XX,+8] who was referred for ovarian failure. The clinical presentation was highly unusual and the patient does not exhibit the characteristic phenotype of trisomy 8 syndrome. Interphase cytogenetics using FISH-technique revealed discrepancies with a different population of cells when compared with its metaphase index.

Enumeration of semen leucocytes by fluorescence in situ hybridisation technique.

Aim-To determine whether the fluorescent in situ hybridisation technique (FISH) using a total human DNA genomic probe can be used to enumerate semen leucocytes.Methods-Semen samples from five donors were subjected to a mild KC1 solution. These samples were then biotin labelled under FISH conditions using a total human DNA genomic probe and the leucocyte counts were determined.

Characterization of 7q--by FISH technique of a case with acute myelogenous leukemia evolving from agnogenic myeloid metaplasia.

We present a new case of acute myelogenous leukemia (AML) which evolved from agnogenic myeloid metaplasia (AMM). Routine cytogenetic techniques revealed a terminal deletion of one chromosome 7 (del (7) (q21)). When metaphases were hybridized with the 7q specific telomeric probe, a signal was detected at the distal q arm of the deleted chromosome 7 suggesting an interstitial deletion and the cytogenetic diagnosis was changed to 46,XY, del(7) (q21.

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.

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.

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.

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.