G-bands By Trypsin Using Giemsa Research Articles

Clinical, Phenotypic, and Demographic Characteristics of Peruvian Children and Neonates with Autosomal and Sex Chromosome Aneuploidies.

Autosomal and sex chromosome aneuploidies are associated with multiple risk factors that determine their frequency and their social and health impact. We aimed to determine the clinical, phenotypic, and demographic characteristics of Peruvian children and neonates with autosomal and sex chromosome aneuploidies. This was a retrospective study conducted on 510 pediatric patients. We conducted a cytogenetic analysis with G-bands by trypsin using Giemsa (GTG) banding, and the results were reported using the International System for Cytogenetics Nomenclature 2013 system. Of 399 children (mean age 2.1 ± 4 years), 84 (16.47%) had aneuploidies, with 86.90% being autosomal (73.81% trisomies). In autosomal aneuploidies, 67.85% (n = 57) of the children had Down syndrome where the most common cause was free trisomy 21 (52 cases, 61.91%), followed by Robertsonian translocation (4 cases, 4.76%). Edwards and Patau syndrome affected 4 (4.76%) and 1 (1.19%) neonate. The most frequent phenotypic characteristics in children with Down syndrome were Down syndrome-like facies (45.61%) and macroglossia (19.29%). Of sex chromosome aneuploidies, 6/7 were abnormalities of the X chromosome (mainly 45,X). Neonate's age (19 ± 44.9 months), paternal age (49 ± 9 years), height (93.4 ± 176 cm), and gestational age (30 ± 15.4 weeks) were significantly correlated with the presence of sex chromosome and autosomal aneuploidies (P < .001; P = .025; and P = .001). Down syndrome and Turner's syndrome were the most frequent aneuploidy and sex chromosome aneuploidy, respectively. In addition, some of the clinical, phenotypic, and demographic characteristics, such as newborn's age, paternal age, gestational age, and height, were significantly correlated with the occurrence of aneuploidy. In this sense, these characteristics could be considered risk factors among this population.

Uveadermatological syndrome (Vogt-Koyanagi-Harada-Like Syndrome) with depigmentation in a husky

SUMMARY The aim of this study to present the cytogenetic approach in a case of uveodermatologic syndrome in a 18-months-old, male, Siberian Husky. This dog was referred with a history of vision impairment and bilateral redish eyes. Clinical examination confirmed depigmentation over the lips and mouth mucosal area. On ophthalmic examination there was bilateral dilated pupilla, depigmentation of the fundus with visionable choroidal vessels, posterior uveitis, and loss of vision. A presumptive diagnosis of uveodermatological syndrome was made. Complete blood counts and biochemical parameters were normal. The case was cytogenetically evaluated, and GTG (G-bands by trypsin using Giemsa)-banding was performed. No numerical chromosomal anomalies were found. Medical treatment consisted in oral and topical administration of dexamethazone, with 1% syclopantholathydroclorur eye drop. To depressed immune reaction azathioprine also given by oral route. Dermatologic signs showed good improvement but the dog remained blind.

Chromosomal analysis from blood: 18 year experience of Songklanagarind Hospital

Metaphase chromosome analysis from cultured blood lymphocytes were investigated in 5,866 tests at Songklanagarind Hospital from 1990 through 2007 (18 years). Elaboration of G-bands by trypsin using Giemsa (GTG) was routinely employed with other banding techniques if required. High resolution chromosome banding was performed in suspected cases of structural chromosome abnormality. Successful studies were obtained in 5,665 tests (96.4 %) and 1,680 tests (28.7 %) were found to have chromosomal abnormalities. The failure rate was 3.4 % (201 tests). Fifty duplicated tests were discarded of the 1680 abnormal results, leaving 1,630 cases with abnormal chromosomes. Of 1,630 cases, Down, Edwards, and Patau syndromes were found in 933 (57.2 %), 87 (5.3 %) and 80 (4.9 %) cases, respectively. There were 215 cases with sex chromosome abnormalities (13.2 %), including 188 cases with Turner syndrome, 18 cases with Klinefelter syndrome, 6 cases with XXX syndrome and 3 cases with XYY syndrome. Androgen insensitivity syndrome (female with 46,XY) was found in 23 cases, and structural chromosome abnormalities were found in 222 cases (13.6 %). The remainder (70 cases/4.3 %) was composed of microdeletion, marker chromosome, fragile X syndrome and rare trisomy. To the best of our knowledge, this study is the largest group of chromosome analysis results reported from Thailand. These findings can be available to provide the database for genetic counseling.

Cytogenetic stability of chicken T-cell line transformed with Marek's disease virus: atomic force microscope, a new tool for investigation

The Marek's disease virus (MDV) integration may induce a novel organization of chromatin architecture with a modified genetic expression. In our opinion it is worthwhile trying to relate cytogenetic stability to functional modifications. Recently, atomic force microscopy technique was applied to study the structure of chromosomes at a nanoscale level. This high resolution allows to investigate the different structure of chromatin in order to study cytogenetic stability and chromosome aberrations due to MDV insertion. In this paper data are presented indicating a duplication [78,WZ,dup(1p)(p22-p23)] and a deletion [78,WZ cht del(3)(q2.10)] of Chromosomes 1 and 3 relatively. Relationships between GTG (G-bands by Trypsin using Giemsa) bands and the topography of chromosomes are also discussed, naming them Topographic Banding. The architecture of chromosomes observed by AFM can be related to the data obtained with classic banding techniques thus overcoming the optical resolution limits. The presence of chromatin bridges between sister chromatids at most of the heterochromatic regions is also evidenced. Besides, we present different studies of the longitudinal and transversal symmetry of the hetero and euchromatic regions to clearly demonstrate a different underlying architecture of these regions. It is indeed evident that the heterochromatic bands are more symmetrical than euchromatic bands.

Case report of de novo dup(18p)/del(18q) and r(18) mosaicism

This is a report of a 27-year-old woman with an unusual de novo chromosomal abnormality. Mosaicism was identified in peripheral blood cells examined by standard G-bands by trypsin using Giemsa (GTG) analysis and fluorescence in situ hybridization (FISH) analysis with chromosome-18 region-specific probes, 46,XX,del(18)(pter --> q21.33:)[41], 46,XX,r(18)(::p11.21 --> q21.33::)[8], and 46,XX,der(18)(pter --> q21.33::p11.21 --> pter)[1]. On the other hand, the karyotype of periodontal ligament fibroblasts was nonmosaic, 46,XX, der(18)(pter --> q21.33::p11.21 --> pter)[50]. All cell lines appeared to be missing a portion of 18q (q21.33 --> qter). The pattern of the dup(18p)/del(18q) in the rod configuration raises the possibility of an inversion in chromosome 18 in one of the parents. However, no chromosomal anomaly was detected in either parent. The most probable explanation is that de novo rod and ring configurations arose simultaneously from an intrachromosomal exchange. The unique phenotype of this patient, which included primary hypothyroidism and primary hypogonadism, is discussed in relation to her karyotype.

High-resolution R-banding at the 1250-band level

High-resolution human chromosomes were obtained from lymphocytes after thymidine synchronization. The block was released either with thymidine to produce GTG (G-bands by trypsin using Giemsa) and RHG (R-bands by heating using Giemsa) banding or with BrdU (5-bromo-2'-deoxyuridine) for RBG (R-bands by BrdU using Giemsa) banding. RHG and RBG band patterns are only 75 to 85% congruent. The dissimilarities increase with the band number per genome and vary from one chromosome region to another. After high-resolution RBG banding, the BrdU-substituted bands show an unequal condensation delay, which can be, according to the bands involved, very important, minimal, or even absent. The bands showing the highest degree of condensation delay are the bands replicating the latest. The GTG- and RHG-band patterns show complementary matching for about 90% of the bands. It was found that two third of the chromosome surface appears positively stained after R-banding. This suggests that more DNA is replicated during early S-phase than during late S-phase. To obtain a fully developed RBG-band pattern in 90 to 95% of harvested mitoses, a period of 4.5 hours after the removal of the blocking agent is optimal. Such a brief release period also implies that late S-phase is much shorter than early S-phase.

Chromosomal Abnormalities in Endometrial and Ovarian Carcinomas

Chromosomal Abnormalities in Endometrial and Ovarian CarcinomasDevelopment and progression of human malignancies involve multiple genetic changes including chromosomal instabilities such as translocations, deletions, and inversions. Chromosomal abnormalities were observed in 23 cases with ovarian and endometrial cancer by cytogenetic studies using a GTG (G bands by trypsin using Giemsa) banding technique. Specific chromosome bands were frequently involved, and were most frequent on chromosomes 1, 2, 3, 5, 12 and 17. Clonal alterations were observed at the cancer breakpoints, such as 1q21, 1q32, 3p21, 7q22, 11q23 in ovarian and 1p36, 1q32, 2p12, 3p21, 7q22, 9q34, 11p15, 11q23, 12q13, 14q11, 14q32, 16p13, 21q22 in endometrial cases. These findings provide evidence that multiple genetic lesions are associated with the pathogenesis of endometrial and ovarian cancer.

Prenatal detection of a de novo Yqh-acrocentric translocation

Objectives To identify the extra chromosomal material on 46,XX,21p+ for prenatal diagnosis. Design and methods Conventional cytogenetic studies using GTG (G bands by trypsin using Giemsa) and CBG (C bands by barium hydroxide using Giemsa) techniques were performed on chromosomes at metaphase obtained from cultured amniocytes and parental blood lymphocytes. Molecular cytogenetic techniques, QF-PCR (quantitative fluorescent polymerase chain reaction), FISH (fluorescent in-situ hybridization), and DA-DAPI (Distamycin A and 4,6-diamino-2-phenylindole) staining, were then used to clarify the extra material present on fetal chromosome 21 p. Results The extra material on fetal chromosome 21 p has originated from Yqh, most likely at PAR2 (the secondary pseudoautosomal region). The karyotype should be 46,XX,der(21)t(Y;21)(q12;p13)de novo.ish der(21)t(Y;21)(q12;p13) (EST Cdy16c07+). Conclusion This case demonstrates the usefulness of molecular techniques in the investigation of rare chromosomal rearrangements.

Is cytogenetic diagnosis of 46,XX karyotype spontaneous abortion specimens erroneous? Fluorescence in situ hybridization as a confirmatory technique

Performing the standard cytogenetic technique on spontaneous abortion material is still a valuable tool, but finding a normal 46,XX karyotype can confuse investigators and lead to a problem in diagnosis. This is mainly because it is possible for the female or male conceptus to retain contaminating maternal cells. To address this possibility, we used fluorescence in situ hybridization technique (FISH). X (DXZ1: p11.1-q11.1 region) and Y (DYZ3: p11.1-q11.1 region) chromosome alpha-satellite probes were employed to confirm the karyotypes previously diagnosed as 46,XX by our cytogenetic laboratory, or to verify the occurrence of 'Y chromosome component'. Besides conventional long-term tissue cultures and G-bands by trypsin using Giemsa (GTG) bandings, FISH analyses were also performed. A total of 134 spontaneous abortion specimens (singleton gestations) were referred for cytogenetic evaluation, of which 125 specimens were successfully karyotyped. Of these, 20.8% (26/125) had chromosome aberrations; 88.5% (23/26) of these aberrations were numerical and 11.5% (3/26) were structural. The most prevalent numerical anomalies were trisomies 15, 16 and 21, tetraploidies, triploidies and monosomy X. FISH results were obtained for 45 out of 92 cases with 46,XX, of which 2 (4.4%) showed XY signals. For accurate cytogenetic evaluation of spontaneous abortion materials, an additional technique such as FISH is required in order to confirm the cytogenetic results or to provide an estimate of the error rate in the analysis of miscarriages.

Epilepsy and neurological findings in 11 individuals with 1p36 deletion syndrome

The 1p36 deletion syndrome is a newly delineated multiple congenital anomalies/mental retardation syndrome characterized by mental retardation, growth delay, epilepsy, congenital heart defects, characteristic facial appearance, and precocious puberty. We analyzed 11 patients by fluorescence in situ hybridization (FISH) using commercially available bacterial artificial chromosome and P1-derived artificial chromosome genomic clones to define the chromosomal deletion responsible for the 1p36 deletion syndrome. Cytogenetic investigation revealed two cases with a terminal deletion of 1p36. Nine patients had an apparently normal karyotype with standard G-bands by trypsin using Giemsa (GTG), but FISH screening with the highly polymorphic genetic marker D1Z2, which is mapped to 1p36.3 and contains an unusual reiterated 40-bp variable number tandem repeat, revealed a submicroscopic deletion. All patients had severe to profound mental retardation. Based on the University of California Santa Cruz Genome Browser, we constructed a deletion map and analyzed the relationship between neurological findings and chromosomal deletions for the 11 cases. Six cases had intractable epilepsy and three had no seizures. The common deletion interval was about 1 million base pairs (Mbp) located between RP11-82D16 and RP4-785P20 (Rho guanine exchange factor (GEF) 16). The severity of clinical symptoms correlates with the size of the deletion. This is demonstrated by the 3 patients with at least 8 Mbp deletions that display profound mental retardation and congenital heart defects. Although haploinsufficiency of the potassium channel beta-subunit ( KCNAB2) is thought to be responsible for intractable seizures in the 1p36 deletion syndrome, this was not the case for 3 of the 11 patients in this study. Further investigation of the 1p36 region is necessary to allow identification of genes responsible for the 1p36 deletion syndrome.