Autosomal Chromosome Abnormalities Research Articles

The Types and Frequencies of X Chromosome Abnormalities in Women with Reproductive Problems

Introduction: X chromosome architecture and integrity are essential for normal ovarian function. Both numerical and structural X chromosome abnormalities play an important role in female infertility. This study aimed to determine the types and frequency of X chromosome aberrations detected in women referred for cytogenetic investigation due to reproductive problems. Methods: 2,936 women (average age: 37.5 years) were enrolled in the present study. Peripheral blood karyotyping was performed by conventional cytogenetic techniques. For each woman, 20 G-banded metaphases were studied and in case of suspected mosaicism, analysis was extended to 100 metaphases. Results: 2,588/2,936 (88.15%) of women had a normal karyotype (46,XX), while 348/2,936 (11.85%) had an abnormal one. Thirty-two women (1.09%) carried autosomal chromosome abnormalities and 316 (10.76%) had X chromosome rearrangements. In 311/2,936 women (10.59%), X chromosome numerical aberrations were detected (low-level mosaicism), and in 5/2,936 cases (0.17%), X structural abnormalities (two with pericentric inversion, one with Xq deletion and two 45,X mosaics, one with an Xp deletion cell line and the other with isochromosome Xq cell line). Low-level X mosaicism was a common finding in women >35 years as compared to younger ones (92.93% vs. 7.07%), a finding consistent with loss of chromosome X with aging. Other X chromosome abnormalities were detected in younger women (32.3 ± 4.13 vs. 41.04 ± 4.5 years). The mean age of women with Turner-like phenotype was 28.75 ± 6.6 years. Conclusion: The study confirms that the incidence of X chromosome abnormalities is increased in women with fertility problems and that karyotype is the gold standard for their identification. Genetic counseling is recommended in these cases to provide information concerning available treatment and fertility options.

Cytogenetic Investigations and Y-Chromosome Microdeletion Screening in some Infertile Kurdish males In Erbil province/ Iraq

Infertility is a disease of the reproductive system defined by the failure to achieve a clinical pregnancy after 12 months or more of regular unprotected sexual intercourse. Worldwide, infertility affects approximately 15% of all couples trying to conceive. Male infertility is responsible for about 50% of the infertility cases. Chromosomal abnormalities and Y-chromosome microdeletions are the most common genetic causes of male infertility. Klinefelter syndrome (KS) is the most prevalent factor of the chromosomal abnormality in the infertile male. Azoospermia Factor (AZF) microdeletions located on the Y chromosome are one of the recurrent genetic cause of male infertility. This study aims to investigate the prevalence of chromosomal anomalies and AZF microdeletions in 296 infertile Kurdish men in Erbil province, 289 patients diagnosed as azoospermia (97.6%) and 7 patients as severe oligozoospermia (2.4%) and 50 healthy men as control group. Twenty nine patients (9.8%) had various chromosomal abnormalities. The most common chromosomal abnormalities were found in sex chromosomes (93.1%; 29/27), among these abnormalities 20 patients (69%) had Klinefelter syndrome 47,XXY karyotype, 4 patients (13.8%) had 45X0/46, Xder(Y), 2 patients (6.9%) had XXY t(11;22)(q25;q13) and 1 patients (3.4%) had Mosaic Turner syndrome 46XY/45X0. The autosomal chromosomal abnormalities (6.9%; 2/29) detected in 2 patients 45, XY, rob (13;14) (q10;q10). Y chromosome microdeletions were found in 10 of 289 patients with azoospermia (3.5%), three of them (30%) had microdeletions in the AZFc region, 3 of them (30%) had microdeletions in the AZFb region, also other 3 patients had microdeletions in the b and c of AZF (AZF b,c) region, and the final one patient (10%) had microdeletions in the all a, b and c (AZF a,b,c) region. Combined Y chromosome microdeletions and chromosomal abnormalities were detected in 3 patients.

Chromosomal aneuploidies and associated rare genetic syndromes involved in male infertility

Background and objectives: Recent investigations have reported more than 70 genetic syndromes involved in male infertility; however, the majority of these syndromes are extremely rare. We aimed to report the most common chromosomal abnormalities and associated rare genetic syndromes in the context of human male infertility. Materials and Methods: We performed a review of published articles considering the most common chromosomal aneuploidies and rare genetic syndromes associated with male infertility on PubMed, Web of Science, and Scopus. Results: Chromosomal abnormalities are frequently found in infertile men, with an incidence rate of 2-15%. The chromosomal aberrations include the sex and autosomal chromosome abnormalities, as well as numerical and structural defects in chromosomes. There are various rare genetic syndromes involved in male infertility that are caused by structural and numerical abnormalities in chromosomes. Klinefelter syndrome is the most common type of sex chromosome aneuploidy in infertile males. Besides, Y chromosome microdeletions, particularly in azoospermia factor regions, serve as the second most common genetic cause of impaired spermatogenetic in infertile men. These molecular genetic abnormalities not only can be inherited, but also they may transmit to the next generation through assisted reproductive techniques and result in the birth of boys with higher risk of congenital abnormalities and infertility. Despite the normal secondary male sexual characteristics, some patients are azoospermic or severe oligozoospermic men. Therefore, identification of these molecular genetic factors and rare genetic disorders is essential in men with unexplained infertility. Discussion and conclusion: Since most of molecular genetic abnormalities can be transmitted to the next generation, identification of these rare genetic disorders is crucial for men with unexplained infertility. It is also essential for clinicians and physicians of reproductive medicine and andrologists to initiate genetic evaluation, aneuploidy screening and counseling prior to any therapeutic procedures.

Cytogenetic findings in Serbian patients with Klinefelter syndrome

Klinefelter syndrome (KS) describes the phenotype of the most common sex chromosome abnormality in humans (1/600 newborn males). The most widespread karyotype in affected patients is 47,XXY, but various others have been described. The aim of this study was to examine the karyotypes of a group of patients suspected of having Klinefelter's syndrome. Between January 1993 and April 2018 104 adult KS patients were evaluated. Cytogenetic analysis was carried out on metaphases obtained from phytohemagglutinin-stimulated peripheral lymphocytes using a standard procedure. Fluorescence in situ hybridization (FISH) analysis was performed on peripheral blood specimens. Vysis CEP X/Y- alpha satellite DNA probes were used to detect X and Y chromosomes. We identified KS presenting the ?standard? or 47,XXY karyotype in eighty three (80%) patients, while five (5%) KS patients showed the mosaic karyotype 47,XXY/46,XY and three (3%) patients had the mosaic karyotype 47,XXY/46,XX. In six (6%) cases KS patients with the ?standard? karyotype also had autosomal chromosomal abnormalities, while numerical sex chromosome abnormalities, with karyotypes 48,XXYY occurred in two (2%) subjects, 47,XYY in three (3%) and 47,XYY/46,XY in two (2%) individuals. Thus, most of our KS patients had the 'standard', 47,XXY karyotype, but some men formed a group of patients with a diversity of other karyotypes. These disparate chromosomal variants may have different physical and mental implications for the general symptomatology of KS. Therefore, it is important to determine the nature of the karyotype of every male with clinical characteristics of KS in very early childhood in order to initiate an adequate, personalized, medical approach.

Chromosomal analyses in genetic counseling of patients with developmental and congenital abnormalities from Belém, Pará State, Brazil: a retrospective study of 17 years

ABSTRACT OBJECTIVE: To present a retrospective study covering 17 years of referral of patients to a public clinical cytogenetic service in Belem, Para State, located in the Brazilian Amazon. MATERIALS AND METHODS: This study was based on a retrospective survey conducted from 1997 to 2014, considering registered chromosome G-banding results and relating them to information collected during patient evaluation. RESULTS: From a total of 1,580 patients, 730 (46.2%) had chromosomal abnormalities, of which 637 (87.3%) showed numerical alterations. Abnormalities involving autosomal chromosomes were more frequent, 524/730 (71.8%), while alterations in sex chromosomes comprised 28.2% (206). Down's syndrome was the most frequent, 424 (58.1%) of cases, followed by 175 (24.0%) cases of Turner's syndrome, and 25 (3.4%) of Klinefelter's syndrome. Patients with sex chromosome abnormalities were referred at a more advanced age when compared with those having autosomal chromosome abnormalities, with peaks around 11-15 years old (30.1% of cases) and 0-6 months old (40.5%), respectively. CONCLUSION: These findings are very similar to other studies and draw attention to public measures to improve both the quality with regard to diagnosis and the subsequent care of the patient. Keywords: Chromosome Disorders; Chromosome Banding; Congenital Abnormalities; Intellectual Disability; Cytogenetics

Longer oral contraception history as a possible preventive factor against fetal trisomy 21 in advanced maternal age pregnancies

Down syndrome is the most common autosomal chromosomal abnormality. According to the classical interpretation, it is the result of meiotic nondisjunction. Its occurrence is more common in advanced maternal age. Despite intensive research, pathophysiology of this genetic disorder is not fully understood. According to recent studies, a different kind of mechanism may be found in the background of trisomy 21 than was previously considered. Based on the ovarian mosaicism model, the cause of trisomy 21 (or any common trisomy) is a segregation error of a chromosome in premeiotic mitosis. The cell entering meiosis will be an oocyte with preexisting trisomy, where its (so-called "secondary") nondisjunction is essential. Maturation of the trisomic oocytes appears to fall behind the disomic oocytes, resulting in their relative accumulation in the ovaries as time progresses. The ratio of trisomic/disomic cells becomes less favorable in maternal maturity. If ovulation is inhibited - although the number of oocytes will continue to decline due to apoptosis - it can be assumed that the trisomic/disomic oocyte ratio remains more favorable with the progression of age. In our summary report, presenting and updating our previous data, we would like to propose that - according to ovarian mosaicism model - long-term oral contraception in the anamnesis may be beneficial in pregnancies with advanced maternal age. Orv Hetil. 2018; 159(28): 1146-1152.

Engineering of Systematic Elimination of a Targeted Chromosome in Human Cells.

Embryonic trisomy leads to abortion or congenital genetic disorders in humans. The most common autosomal chromosome abnormalities are trisomy of chromosomes 13, 18, and 21. Although alteration of gene dosage is thought to contribute to disorders caused by extra copies of chromosomes, genes associated with specific disease phenotypes remain unclear. To generate a normal cell from a trisomic cell as a means of etiological analysis or candidate therapy for trisomy syndromes, we developed a system to eliminate a targeted chromosome from human cells. Chromosome 21 was targeted by integration of a DNA cassette in HeLa cells that harbored three copies of chromosome 21. The DNA cassette included two inverted loxP sites and a herpes simplex virus thymidine kinase (HSV-tk) gene. This system causes missegregation of chromosome 21 after expression of Cre recombinase and subsequently enables the selection of cells lacking the chromosome by culturing in a medium that includes ganciclovir (GCV). Cells harboring only two copies of chromosome 21 were efficiently induced by transfection of a Cre expression vector, indicating that this approach is useful for eliminating a targeted chromosome.

Cytogenetic Analysis in Infertile Male Patients with Oligospermia and Azoospermia in the Southern Region of Iran, Shiraz

Background: Infertility was found to affect approximately 10%-15% of the couples, worldwide. Male factors are responsible for at least 50% of the infertility cases. The chromosomal abnormality is more common in infertile men than in fertile men. However, the aim of this study was to evaluate the frequency and type of major chromosomal abnormalities in the infertile men with problems in their sperm count, who had been referred to cytogenetic center in Shiraz, the main referral center in southern Iran. Materials and Methods: A total of 433 infertile males, with azoospermia [169(31%)] and oligospermia [264(69%)], were included in this prospective observational study. Samples were retrospectively collected from the infertile males, and examined by karyotype analysis. Results: The findings revealed that there are 17.3% chromosomal problems, in which 14.3% and 3% of all cases exhibited numerical and structural abnormalities, respectively. Among the 433 infertile patients, 57(33%) exhibited a numerical sex chromosome abnormality, including 49 (11.3%) subjects with typical Klinefelter syndrome, 4 (2.95%) ones with structural sex chromosome and 11 (4.4%) ones with the autosomal chromosome abnormality. Conclusion: The results from this study demonstrated that chromosomal abnormalities are common in the infertile men with a higher frequency of sex chromosomal abnormality, especially those with the numerical type. This highlights the importance of karyotype findings to make appropriate decisions regarding the management of the patients in infertility clinics.

Cytogenetic findings in patients with intellectual disability and/or multiple congenital anomalies

Introduction: Chromosomal abnormalities are a major etiology of intellectual disability (ID) and multiple congenital anomalies (MCAs). Screening for chromosomal aberrations by clinical diagnostic techniques has been primarily performed through standard karyotyping. Methods: A cytogenetic study involving 1730 individuals with ID and/or MCA was conducted using lymphocyte culture and high-resolution G-banding method. Results: Various types of chromosomal abnormalities were detected in 440 patients (25.5%). Numerical and structural chromosomal abnormalities, respectively, were observed in 63.3% (278 out of 440) and 36.7% (162 out of 440) patients. Among the chromosomal abnormalities, sexual chromosomal abnormalities were found in some cases, and Klinefelter syndrome with 2.5% frequency was the most frequent sex chromosomal abnormality. Autosomal abnormalities were found in cases, and Down syndrome was the most frequent autosomal chromosomal abnormality occurring in 41.0% of detected abnormalities. Conclusion: The higher contribution of chromosome aberrations in the northwest of Iran indicates the importance of cytogenetic evaluation in the etiology of MCA and/or ID patients. Genetic counseling was provided to the family members to explain the recurrence risk as well as the need for prenatal diagnosis in subsequent pregnancies and management of patients by collected data bank.

Clinical features and survival in individuals with trisomy 18: A retrospective one-center study of 44 patients who received intensive care treatments.

Trisomy 18 syndrome is a common autosomal aneuploidy chromosomal abnormality caused by the presence of extra chromosome 18 that leads to malformations of various parts of the body. In this study, we retrospectively investigated the effect of the medical progression and prognosis of 44 cases of trisomy 18, admitted to our neonatal intensive care unit between 1992 and 2013. The patients were divided into group A (n=20, 1992–2002) and group B (n=24, 2003–2012). Following delivery, karyotype, gender, gestational weeks, birth place, cesarean section, Apgar score and birth weight were analyzed using the Fisher's exact test, unpaired t-test and Mann-Whitney U test. Based on the statistical results, a comparison was made of the two groups and no significant differences were observed. Clinical data of major complications, mechanical ventilation, discharge from hospital and survival days were reviewed for the cases of trisomy 18. Of the 44 patients, 42 had cardiac anomaly, 16 had esophageal atresia, and 3 patients had brain anomaly. Ventilation treatment was performed in 29 cases (65.9%) and an increased percentage was identified in group B patients. The percentage survival was estimated using Kaplan-Meier curves and the two groups were analyzed using the generalized Wilcoxon test. Improvement in life prognosis was observed in group B as compared to group A. The log-rank test was used to assess survey periods of 180 days, 1 year, and the entire observation period. Although significant differences were observed for the prognosis of trisomy 18 at 180 days after birth, after 1 year and the entire survey period after birth, the significant differences were not confirmed. In conclusion, results of the present study provide information concerning genetic counseling for parents/guardians and life prognosis, prior to applying intensive management to newborns with trisomy 18.

Chromosomal abnormalities and Y chromosome microdeletions in infertile men from Morocco.

BackgroundMale infertility is responsible for 50 % of infertile couples. Thirty percent of male infertility is due to cytogenetic and genetic abnormalities. In Arab and North African populations, several studies have shown the association of these chromosomal abnormalities with male infertility. Our objective is to evaluate the frequency of chromosomal abnormalities and Y chromosome microdeletions in infertile men from Morocco.MethodsA total of 573 Moroccan infertile men (444 azoospermic and 129 oligozoospermic men) referred for cytogenetic analysis to the Department of Cytogenetics of the Pasteur Institute of Morocco, were screened for the presence of chromosomal abnormalities and Y chromosome microdeletions.ResultsChromosomal abnormalities accounted for approximately 10.5 % (60/573). Fifty six cases among them have sex chromosome abnormalities (93.34 %), including Klinefelter’s syndrome in 41 patients (68.34 %). Autosomal chromosome abnormalities (6.66 %) were observed in 4 patients. Chromosomal abnormalities were more prevalent in azoospermic men (13.06 %) than in oligospermic men (1.55 %). Y microdeletions were detected in 16 of 85 patients (AZFc: 14.12 %, AZFbc: 4.70 %), most of them where azoospermic men with no chromosomal abnormality.ConclusionsThese results highlighted the need for efficient molecular genetic testing in male infertility diagnosis. In addition, a genetic screening should be performed in infertile men before starting assisted reproductive treatments.

Bosentan treatment for pulmonary arterial hypertension due to patent ductus arteriosus and Down's syndrome in an infant

Down's syndrome is the most common autosomal chromosome abnormality with an estimated incidence of approximately 1.1 per 1000 births [ [1] Morris J.K. Alberman E. Trends in Down's syndrome live births and antenatal diagnoses in England and Wales from 1989 to 2008: analysis of data from the National Down Syndrome Cytogenetic Register. BMJ. 2009; 339 Google Scholar ]. The prevalence of congenital heart disease (CHD) in the Down's population is 40–60% [ 2 D'Alto M. Romeo E. Argiento P. et al. Therapy for pulmonary arterial hypertension due to congenital heart disease and Down's syndrome. Int J Cardiol. 2013; 164: 323-326 Abstract Full Text Full Text PDF PubMed Scopus (39) Google Scholar , 3 Suzuki K. Yamaki S. Mimori S. et al. Pulmonary vascular disease in Down's syndrome with complete atrioventricular septal defect. Am J Cardiol. 2000; 86: 434-437 Abstract Full Text Full Text PDF PubMed Scopus (59) Google Scholar , 4 Rowe R.D. Uchida I.A. Cardiac malformation in mongolism: a prospective study of 184 mongoloid children. Am J Med. 1961; 31: 726-735 Abstract Full Text PDF PubMed Scopus (134) Google Scholar ] and patent ductus arteriosus (PDA) is a common congenital heart disease and makes up 5–10% of all heart disease in newborns at term [ 5 Yunfei L. Ke L. Qi A. et al. Transcatheter intervention following ambrisentan treatment in an adult patient with patent ductus arteriosus and severe pulmonary hypertension. Int J Cardiol. 2014; 173 (e16–7) Abstract Full Text Full Text PDF PubMed Scopus (6) Google Scholar , 6 Mitchell S.C. Korones S.B. Berendes H.W. Congenital heart disease in 56,109 births. Incidence and natural history. Circulation. 1971; 43: 323-332 Crossref PubMed Scopus (934) Google Scholar ]. Children with Down's syndrome may develop progressive pulmonary changes earlier than non-Down's counter-parts with similar congenital heart defects and harder to decrease the pressure [ [7] Soudon P. Stijns M. Tremouroux-Wattiez M. et al. Precocity of pulmonary vascular obstruction of Down's syndrome. Eur J Cardiol. 1975; 2: 473-476 PubMed Google Scholar ]. Here we are going to report an infant with pulmonary arterial hypertension due to patent ductus arteriosus and Down's syndrome.

Prevalence and possible causes of hypospadias

Hypospadias is the most common congenital malformation of the male external genitalia. After the heart and circulatory system, it is the second most common developmental disorder in males. It is due to a midline fusion defect of the male urethra, which results in a misplaced urethral meatus. Hypospadias may be distal, medial and proximal. It may occur as an isolated defect or it may develop together with other genital disorders (retention of testes in one or both sides, microphallus, bifid scrotum) or with malformation of other organs. In some cases syndromic forms may also occur. Genetic factors play a crucial role in the occurrence of early developmental defect, but endocrine and environmental factors may also be important in the aetiology of hypospadias. It may be associated with various sex and autosomal chromosomal abnormalities. Monogenic and chromosomal causes of hypospadias accounts for about in 30% of all cases, while genetic factors remain unknown in 70% of cases. The authors summarize the development of the male external genitalia, the prevalence and possible causes of hypospadias. They propose that better understanding of the pathogenesis of the disease may contribute to the prevention and decreased prevalence of the disease.

Chromosomal aberrations and polymorphic evaluation in males with primary infertility from Indian population.

The chromosomal abnormalities are one of the important causes of male infertility. In view of the genetic risks for the next generation, the importance of careful evaluation of karyotype is essential. The objective of this study was to determine the frequency of chromosomal abnormalities in infertile men with primary infertility from Indian population. The 78 infertile men with primary infertility, out of which 26 men were azoospermic, 19 men were oligospermic, 4 men were asthenospermic and 29 men were oligoasthenospermic were studied. Karyoptying was performed on peripheral blood lymphocytes by using the Giemsa trypsin banding (GTG) banding technique. Additional data was collected from published studies in Indian population leading to a total of 1814 cases. Chromosome analysis of 78 infertile males showed major chromosome abnormalities in 10.2%, with 6.4% in autosomal chromosome abnormalities and 3.8% in sex chromosome abnormalities. The incidence of major chromosome abnormalities in oligospermic males were 21% and azoospermic males were 15.4 %. Chromosomal polymorphic variants were identified to be 16.7%. Combining the data from other published studies identified 153/ 1814 (8.4%) infertile men of chromosomal abnormalities; with 10.8% in azoospermia, 7.3% in oligospermia and 7.3% in oligoasthenoteratospermic from India. The overall high prevalence of chromosomal abnormalities in infertile males suggests that the conventional chromosomal analysis is an important investigative tool for male infertility, especially prior to use of any assisted reproductive techniques.

The Cytogenetic Basis of Human Infertility: A Review

Infertility resulting in humans has evoked considerable legal, medical and social interests. Infertility remains a major public health problem. Epidemiological studies reveal that genetic and environmental factors are responsible for infertility. As an estimate nearly 15-20% of couples have difficulty or is unable to conceive. Infertility is multi-factorial, but primarily it is because of male factor, female factor or a combination of both. Infertility can be hormonal, related to age, obesity, and infectious diseases, psychological or genetic. The genetic causes of infertility can be Y chromosome deletion, single gene disorder, multi-factorial causes and chromosomal abnormalities. The incidence of autosomal chromosome abnormalities is 1.1 to 7.2% in infertile men, about 3% in the azoospermia group and up to 10.2% in the oligozoospermia group. Genetic research on infertility aims to correlating clinical consequences and genotype.

Miscarriage in contemporary maternal-fetal medicine: targeting clinical dilemmas

Miscarriage in contemporary maternal-fetal medicine: targeting clinical dilemmas

Clinical Correlates of Autosomal Chromosomal Abnormalities in an Electronic Medical Record–Linked Genome-Wide Association Study

Although mosaic autosomal chromosomal abnormalities are being increasingly detected as part of high-density genotyping studies, the clinical correlates are unclear. From an electronic medical record (EMR)–based genome-wide association study (GWAS) of peripheral arterial disease, log-R-ratio and B-allele-frequency data were used to identify mosaic autosomal chromosomal abnormalities including copy number variation and loss of heterozygosity. The EMRs of patients with chromosomal abnormalities and those without chromosomal abnormalities were reviewed to compare clinical characteristics. Among 3336 study participants, 0.75% (n = 25, mean age = 74.8 ± 10.7 years, 64% men) had abnormal intensity plots indicative of autosomal chromosomal abnormalities. A hematologic malignancy was present in 8 patients (32%), of whom 4 also had a solid organ malignancy while 2 patients had a solid organ malignancy only. In 50 age- and sex-matched participants without chromosomal abnormalities, there was a lower rate of hematologic malignancies (2% vs 32%, P < .001) but not solid organ malignancies (20% vs 24%, P = .69). We also report the clinical characteristics of each patient with the observed chromosomal abnormalities. Interestingly, among 5 patients with 20q deletions, 4 had a myeloproliferative disorder while all 3 men in this group had prostate cancer. In summary, in a GWAS of 3336 adults, 0.75% had autosomal chromosomal abnormalities and nearly a third of them had hematologic malignancies. A potential novel association between 20q deletions, myeloproliferative disorders, and prostate cancer was also noted.

Chromosome abnormalities in Indonesian patients with short stature

BackgroundShort stature is associated with several disorders including wide variations of chromosomal disorders and single gene disorders. The objective of this report is to present the cytogenetic findings in Indonesian patients with short stature.MethodsG-banding and interphase/metaphase FISH were performed on short stature patients with and without other clinical features who were referred by clinicians all over Indonesia to our laboratory during the year 2003–2009.ResultsThe results of chromosomal analysis of ninety seven patients (mean age: 10.7 years old) were collected. The group of patients with other clinical features showed sex chromosome abnormalities in 45% (18/40) and autosomal abnormalities in 10% (4/40), whereas those with short stature only, 42.1% (24/57) had sex chromosome abnormalities and 1.75% (1/57) had autosomal abnormalities. The autosomal chromosomal abnormalities involved mostly subtelomeric regions. Results discrepancies between karyotype and FISH were found in 10 patients, including detection of low-level monosomy X mosaicism in 6 patients with normal karyotype, and detection of mosaic aneuploidy chromosome 18 in 1 patient with 45,XX,rob(13;14)(q10;q10).Statistical analysis showed no significant association between the groups and the type of chromosomal abnormalities.ConclusionChromosome abnormalities account for about 50% of the short stature patients. Wide variations of both sex and autosomal chromosomes abnormalities were detected in the study. Since three out of five patients had autosomal structural abnormalities involving the subtelomeric regions, thus in the future, subtelomeric FISH or even a more sensitive method such as genomic/SNP microarray is needed to confirm deletions of subtelomeric regions of chromosome 9, 11 and 18. Low-level mosaicism in normal karyotype patients indicates interphase FISH need to be routinely carried out in short stature patients as an adjunct to karyotyping.

Cytogenetic analysis of 4216 patients referred for suspected chromosomal abnormalities in Southeast Turkey

We reviewed cytogenetic studies performed on 4216 patients who were referred to the Cytogenetics Unit at Dicle University Hospital, Diyarbair, Southeast Turkey, between 2000 and 2009. The cases were grouped according to the reason of referral for cytogenetic analysis. The frequencies of the different types of numerical and structural abnormalities were determined, and the relative frequency of cases with abnormal karyotypes was calculated in each group. The most common reason for requesting cytogenetic testing was referral for Down syndrome and for repeated abortions. The highest frequencies of abnormal karyotypes were found among cases that were referred due to suspicion of Down syndrome (84.8%). Among the chromosomal abnormalities, sexual chromosomal abnormalities were found in 239 cases (17.6%), and Klinefelter syndrome was the most frequent sex chromosomal abnormality. Autosomal abnormalities were found in 1119 cases (82.4%), and Down syndrome was the most frequent autosomal chromosomal abnormality. In conclusion, the high rate of chromosomal abnormalities (32.2%) found in this population demonstrates the importance of cytogenetic evaluation in patients who show clinical abnormalities. This is the first report on cytogenetic testing in the southeast region of Turkey. This type of study provides a basis for determining the risks of recurrence and for deciding on clinical treatment and genetic counseling.

Cinquantenaire de la trisomie 21

Fifty years ago, I was co-author of the first paper asserting the presence of a supernumerary chromosome in Down's syndrome (called "mongolism" in France at that time). This first autosomal chromosomal abnormality was called Trisomy 21. It seemed to me historically interesting to bring my own testimony as an actor in this discovery.