Molecular cytogenetic and phenotypic characterization of ring chromosome 13 in three unrelated patients.

We report on the cytogenetic and molecular investigations of constitutional de-novo ring chromosome 13s in three unrelated patients for better understanding and delineation of the phenotypic variability characterizing this genomic rearrangement. The patient's karyotypes were as follows: 46,XY,r(13)(p11q34) dn for patients 1 and 2 and 46,XY,r(13)(p11q14) dn for patient 3, as a result of the deletion in the telomeric regions of chromosome 13. The patients were, therefore, monosomic for the segment 13q34 → 13qter; in addition, for patient 3, the deletion was larger, encompassing the segment 13q14 → 13qter.

Xp22.3 interstitial deletion: a recognizable chromosomal abnormality encompassing VCX3A and STS genes in a patient with X-linked ichthyosis and mental retardation.

X-linked ichthyosis is a genetic disorder affecting the skin and caused by a deficit in the steroid sulfatase enzyme (STS), often associated with a recurrent microdeletion at Xp22.31. Most of the STS deleted patients have X-linked ichthyosis as the only clinical feature and it is believed that patients with more complex disorders including mental retardation could be present as a result of contiguous gene deletion.

A novel t(3;12)(q21;p13) translocation in a patient with accelerated chronic myeloid leukemia after imatinib and nilotinib therapy.

The acquisition of secondary chromosomal aberrations in chronic myeloid leukemia (CML) patients with Philadelphia chromosome-positive (Ph+) karyotype signifies clonal evolution associated with the progression of the disease to its accelerated or blastic phase. Therefore, these aberrations have clinical and biological significance. T(3;12)(q26;p13), which is a recurrent chromosomal aberration observed in myeloid malignancies, is typically associated with dysplasia of megakaryocytes, multilineage involvement, short duration of any blastic phase, and extremely poor prognosis.

A cytogenetic approach to the effects of low levels of ionizing radiation (IR) on the exposed Tunisian hospital workers.

Objectives: The aim of this study is to assess chromosomal damage in Tunisian hospital workers occupationally exposed to low levels of ionizing radiation (IR).

Materials And Methods: The cytokinesis-block micronucleus (CBMN) assay in the peripheral lymphocytes of 67 exposed workers compared to 43 controls matched for gender, age and smoking habits was used. The clastogenic/aneugenic effect of IR was evaluated using the CBMN assay in combination with fluorescence in situ hybridization with human pan-centromeric DNA in all the exposed subjects and controls.

Phenotype and micro-array characterization of duplication 11q22.1-q25 and review of the literature.

Partial duplication of 11q is related to several malformations like growth retardation, intellectual disability, hypoplasia of corpus callosum, short nose, palate defects, cardiac, urinary tract abnormalities and neural tube defects. We have studied the clinical and molecular characteristics of a patient with severe intellectual disabilities, dysmorphic features, congenital inguinal hernia and congenital cerebral malformation which is referred to as cytogenetic exploration. We have used FISH and array CGH analysis for a better understanding of the double chromosomic aberration involving a 7p microdeletion along with a partial duplication of 11q due to adjacent segregation of a paternal reciprocal translocation t(7;11)(p22;q21) revealed after banding analysis.

A PML/RARA chimeric gene on chromosome 12 in a patient with acute promyelocytic leukemia (M4) associated with a new variant translocation: t(12;15;17)(q24;q24;q11).

Acute promyelocytic leukemia (APL) is genetically characterized by a reciprocal translocation between chromosomes 15 and 17, t(15;17)(q22;q21), which results in the fusion gene PML-RARA. A small proportion of patients with APL have complex or simple variants of this translocation. With conventional cytogenetic methods, these translocations are detected in about 70-90 % of patients, with most of the negative results due to technical problems or cryptic variants.

Analysis of the clinico-hematological relevance of the breakpoint location within M-BCR in chronic myeloid leukemia.

The Philadelphia chromosome (Ph) derives from the balanced translocation between chromosomes 9 and 22. This chromosomal translocation results in the fusion between the 5' part of the BCR gene, normally located on chromosome 22, and the 3' part of the ABL gene on chromosome 9 giving origin to a BCR-ABL fusion gene which is transcribed and then translated into a hybrid protein. In general, three breakpoint cluster regions in the BCR gene have been described: major (M-BCR), minor (m-BCR) and micro (μ-BCR).

A combination of micronucleus assay and fluorescence in situ hybridization analysis to evaluate the genotoxicity of formaldehyde.

A genotoxic effect of formaldehyde (FA), particularly micronucleus (MN) induction, has been shown in several previous studies. The aim of the present study was to assess the frequency of micronuclei and to identify the type of chromosomal damage in Tunisian staff members working in the Pathologic Anatomy Laboratory of Farhat Hached hospital (Sousse, Tunisia) who were exposed to FA. Assessment of chromosomal damage was performed in peripheral lymphocytes of 31 FA-exposed employees compared with 31 control employees working in the administrative department of the same hospital.

Mutational screening of SF1 and WNT4 in Tunisian women with premature ovarian failure.

Background: WNT4 and SF1 genes play an important role in ovarian development. They constitute coherent candidate genes associated with premature ovarian failure (POF) pathogenesis.

Methods: We sequenced the coding region of WNT4 and SF1 in 55 Tunisian women with POF and 100 healthy controls.

Cytogenetic analysis in a large series of children with non-syndromic mental retardation.

Mental retardation affects 1-3% of the population. To evaluate the implication of chromosomal abnormalities in the etiology of mental retardation, 1420 patients with non-syndromic mental retardation recruited at the department of cytogenetics of Farhat Hached hospital (Sousse, Tunisia) between January 2005 and December 2009, were analyzed using standard cytogenetic techniques. Age ranged between 3 and 18 years with a median of 8 years.

Comprehensive analysis of BCR/ABL variants in chronic myeloid leukemia patients using multiplex RT-PCR.

Background: A specific chromosomal abnormality, the Philadelphia chromosome (Ph), is present in 90 - 95% of patients with chronic myeloid leukemia (CML). This aberration results from a reciprocal translocation between chromosomes 9 and 22, creating a BCR/ABL fusion gene. The diagnosis of CML is based on the detection of BCR/ABL gene or Ph chromosome.

Chromosomal microarray analysis of functional Xq27-qter disomy and deletion 3p26.3 in a boy with Prader-Willi like features and hypotonia.

Duplications of the long arm of the X chromosome are rare. The infantile phenotype shares some resemblance with the Prader-Willi syndrome, presenting severe psychomotor retardation, facial dysmorphic features with a broad face, a small mouth and a thin pointed nose, hypotonia, urogenital malformation and proneness to infections. We report a boy with an additional Xq27-qter chromosome segment translocated onto the short arm of chromosome 3.

Trisomy and tetrasomy 15q11-q13 diagnosed by molecular cytogenetic analysis in two patients with mental retardation.

In this study, we report two patients with the supernumerary marker chromosome (15)s. The first case is an 8.5-year-old girl with an inv dup (15) syndrome, mental retardation and dysmorphic features.

Cytogenetic and molecular aspects of absolute teratozoospermia: comparison between polymorphic and monomorphic forms.

Objective: To compare the results of cytogenetic and molecular analysis between absolute polymorphic and monomorphic teratozoospermia.

Methods: The semen samples from patients with polymorphic teratozoospermia (n = 20), globozoospermia (n = 8), or macrocephalic sperm head syndrome (n = 12), and healthy fertile men (n = 20) were analyzed according to the World Health Organization criteria. The constitutional blood karyotype of the patients was performed on cultured lymphocytes, according to standard techniques.

Clinical and molecular characterization of a combined 17p13.3 microdeletion with partial monosomy 21q21.3 in a 26-year-old man.

We led a clinical and molecular characterization of a patient with mild mental delay and dysmorphic features initially referred for cytogenetic exploration of an azoospermia. We employed FISH and array CGH techniques for a better definition and refinement of a double chromosome aberration associating a 17p microdeletion with partial monosomy 21q due to 1:3 meiotic segregation of a maternal reciprocal translocation t(17;21)(p13.3;q21.

Aneuploidy rate in spermatozoa of selected men with severe teratozoospermia.

The aim of this study was to evaluate the incidence of spermatic aneuploidies in men with severe teratozoospermia and to determine an eventual relation between aneuploidies and a specific morphology of spermatozoa. Fluorescence in situ hybridisation (FISH) using a probe cocktail containing the alpha satellite for the centromeric region of chromosome X, Y and 18 was performed on decondensed spermatozoa from fresh ejaculates of thirty patients with severe teratozoospermia (abnormal forms >80%) and 15 fertile men with normal semen profiles. The mean frequency of teratozoospermia in patients was 91 ± 6.

Assessment of chromosomal aberrations, micronuclei and proliferation rate index in peripheral lymphocytes from Tunisian nurses handling cytotoxic drugs.

Anti-neoplastic agents are widely used in the treatment of cancer and some non-neoplastic diseases. These drugs have been proved to be mutagens, carcinogens and teratogens. To check the eventual effects of anti-cancer drugs on occupationally exposed Tunisian nurses, we used chromosomal aberration assay and micronucleus assay.

Molecular cytogenetic characterization of Philadelphia-negative rearrangements in chronic myeloid leukemia patients.

Background: The BCR/ABL gene rearrangement is generated by a reciprocal translocation t(9;22)(q34;q11) in chronic myeloid leukemia (CML) patients. In most cases, it is cytogenetically visualized by the Philadelphia (Ph) chromosome. About 5-10% of CML patients lack cytogenetic evidence of the Ph translocation but show BCR/ABL fusion by fluorescence in situ hybridization (FISH) or reverse transcriptase-polymerase chain reaction (RT-PCR).

Molecular cytogenetic study of derivative chromosome 9 deletion in chronic myeloid leukemia patients.

The aims of this study are to investigate the frequency of derivative chromosome 9 (der (9)) deletion in Tunisian patients with chronic myeloid leukemia (CML) and to assess the correlation between this deletion and the cytogenetic response for patients treated with hydroxyurea (HU) or imatinib (IM). Karyotype analysis of 336 patients with CML was performed with R-banding technique. Fluorescence in situ hybridization (FISH) was carried using home-brew probes 17L7 and 248J22 for detecting, respectively, adjacent 5'ABL and 3'BCR deletions on der(9).

Translocation t(X;10)(p10;p10): a rare chromosomal abnormality in a new born female with acute myeloid leukemia.

Sex chromosomes are infrequently involved in patients with hematologic malignancies. In most instances, the abnormality is either duplication in the q arm or deletion and translocation involving the q13 and q24 regions. We report herein a rare translocation t(X;10)(p10;p10) in a newborn with 2 months and 20 days with acute myeloid leukemia (AML) (FAB, M4).

Analysis of sperm aneuploidies and DNA fragmentation in patients with globozoospermia or with abnormal acrosomes.

Objectives: To evaluate the levels of DNA fragmentation and aneuploidy rate in ejaculated sperm of men with globozoospermia and men with a predominance of abnormal acrosomes.

Methods: The semen samples obtained from 2 globozoospermic men, 8 patients with a predominance of abnormal acrosomes, and 20 fertile men were analyzed using the fluorescence in situ hybridization and the terminal desoxynucleotidyl transferase-mediated deoxyuridine triphosphate biotin nick-end labeling assay. Dual fluorescence in situ hybridization for chromosomes 8 and 12, and triple fluorescence in situ hybridization for chromosomes X, Y, and 18 were performed.

Chromosomal microarray analysis in a girl with mental retardation and spina bifida.

Chromosomal imbalances comprise a major cause of mental retardation, particularly in association with congenital malformations and dysmorphic features. Chromosomal analysis using banded karyotyping is limited by the low resolution of this technique, and cryptic chromosomal rearrangements cannot be detected. We describe a 6-year-old girl with mental retardation, mild growth, congenital malformation, and facial anomalies.

Validation of nomograms to predict the risk of non-sentinels lymph node metastases in North African Tunisian breast cancer patients with sentinel node involvement.

Introduction: In approximately half of patients with breast cancer and lymph node metastases, the sentinel node (SN) is the only involved axillary node. Scoring systems have been developed to predict probability of non-SN metastases among those with a positive SN. The goal of the present study was to determine whether the five models (Memorial Sloan-Kettering Cancer Center (MSKCC), Stanford, Tenon, Cambridge and the Turkish model) accurately predicted non-SN involvement in a North African Tunisian population.

E355G mutation appearing in a patient with e19a2 chronic myeloid leukaemia resistant to imatinib.

The development of imatinib is a milestone in the treatment of chronic myeloid leukaemia (CML), and its therapeutic effect has been extensively investigated in patients with CML who carry M-bcr and m-bcr BCR-ABL fusion transcripts. However, knowledge about its therapeutic effect on patients with CML who have the rare BCR-ABL fusion transcript e19a2 (mu-bcr) remains sparse. This report describes a patient with Philadelphia-positive chronic myeloid leukaemia with e19a2 rearrangement, in whom E355G mutation had been acquired.