Gene Clinic

Tehrān, Iran

Gene Clinic

Tehrān, Iran

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Rafati M.,Tehran University of Medical Sciences | Rafati M.,Comprehensive Genetic Center | Seyyedaboutorabi E.,Islamic Azad University at Tehran | Ghadirzadeh M.R.,Tehran Welfare Organization | And 11 more authors.
Molecular Cytogenetics | Year: 2012

Background: Interstitial Microdeletion and Microduplication syndromes have been proposed as a significant cause of sporadic intellectual disability (ID) but the role of such aberrations in familial ID has not yet been investigated. As the balanced chromosomal abnormalities commonly lead to the recurrent ID or multiple congenital anomalies, this study was designed to evaluate whether it was justified to investigate such aberrations in familial ID patients. Three hundred and twenty eight patients from 101 unrelated Iranian families with more than two ID patients in the first-degree relatives, have been investigated. Assessment of a panel of 21 common Microdeletion and Microduplication syndromes (CMMS) was carried out using Multiplex Ligation-Dependent Probe Amplification (MLPA) technique. Results: Among the families studied, 27.7% had 4-12, 35.6% had 3 and 36.6% had 2 affected individuals in the first-degree relatives. An autosomal dominant inheritance of Williams-Beuren syndrome (WBS) was detected in a family with no clinical suspicion of WBS. The prevalence of CMMS was therefore,0.99%. Conclusion: This is the first investigation of a panel of CMMS in a large sample set of "familial ID patients". The findings of this study showed the low prevalence of CMMSs in "familial ID" patients in spite of the significant contribution of such aberrations in "sporadic ID" which has a very useful practical impact by avoiding unnecessary diagnostic tests in "familial ID" patients. © 2012 Rafati et al; licensee BioMed Central Ltd.


Rafati M.,Tehran University of Medical Sciences | Rafati M.,Comprehensive Genetic Center | Ghadirzadeh M.R.,Tehran Welfare Organization | Heshmati Y.,Tehran Welfare Organization | And 8 more authors.
Molecular Cytogenetics | Year: 2012

Background: Cryptic subtelomeric rearrangements have been proposed as a significant cause of sporadic intellectual disability (ID) but the role of such aberrations in familial ID has not yet been studied. As positive family history of ID had been proposed as an important and significant predicting factor of subtelomeric rearrangements, it was assumed that the contribution of subtelomeric aberrations in familial ID would be much more than the sporadic ones. Three hundred and twenty two patients from 102 unrelated families with more than two ID patients in the first degree relatives have been investigated. Assessment of subtelomeric rearrangements were carried out using Multiplex Ligation-Dependent Probe Amplification (MLPA) technique. Detected aberrations were then confirmed by Fluorescence in Situ Hybridization (FISH) method. Results: Among the families studied, 27.4% had 4-12, 36.3% had 3 and 36.3% had 2 affected individuals in the first degree relatives. One unbalanced translocation and 4 polymorphic changes were detected. The prevalence of clinically significant subtelomeric rearrangements was 0.98%. Conclusion: This is the first investigation of subtelomeric aberrations in a large sample set of familial ID patients. Our results show that the contribution of subtelomeric rearrangements to familial ID is not as much as what had been determined for sporadic ones in the literature. Moreover, this study shows that the positive family history by alone, cannot be the most important and determining indicator of subtelomeric aberrations while it would be a good predicting factor when associated with dysmorphism or congenital malformations. These findings propose that other cryptic chromosomal abnormalities or even single gene disorders may be the main cause of familial ID rather than subtelomeric aberrations. © 2012 Rafati et al; licensee BioMed Central Ltd.


Korzebor A.,Tehran University of Medical Sciences | Derakhshandeh-Peykar P.,Tehran University of Medical Sciences | Meshkani M.,Tehran University of Medical Sciences | Hoseini A.,Comprehensive Genetic Center | And 4 more authors.
Molecular Biology Reports | Year: 2013

Preimplantation genetic diagnosis (PGD) has been considered as an alternative to prenatal diagnosis for prevention of genetic disorders while avoiding the subsequent termination of pregnancy. However, the limited amount of template DNA available in a single diploid cell used for PGD leads to number of problems including an increased incidence of detectable contamination; amplification failure and allele drop out. Due to their highly polymorphic and amplifiable characteristics, short tandem repeat (STR) analysis has been proposed as a mean to overcome these limitations. Heterozygosity of the applied STRs is of paramount importance in their informativity, and should therefore be studied in any certain population. Here, for the first time, we report on the heterozygosity analysis of five STR markers (D5S1408, D5S1417, D5S610, D5S629 and D5S637) flanking to SMA gene region, to examine their applicability in the PGD for SMA disease. We have also investigated other statistical features of these markers and found that all of the five studied STRs were informative and four meet the Hardy-Weinberg equilibrium for the studied population. Furthermore, our results propose that similar approaches can be used for the PGD of other single gene disorders. © 2012 Springer Science+Business Media Dordrecht.


Rafati M.,Tehran University of Medical Sciences | Rafati M.,Comprehensive Genetic Center | Seyyedaboutorabi E.,Islamic Azad University | Brujerdi R.,Islamic Azad University | And 3 more authors.
Clinical Dysmorphology | Year: 2012

Williams-Beuren syndrome (WBS), a contiguous gene deletion syndrome, mostly occurs sporadically. Although a few cases of familial WBS have been reported in the literature, molecular confirmation of the deletion has not been carried out in all of them. Here, we report on the eighth clinically and molecularly confirmed inherited WBS detected in a family with 'familial mental retardation.' A comprehensive screening approach to mental retardation that included stepwise karyotyping, assessment for fragile-X syndrome, subtelomeric rearrangements and known microdeletion/microduplication syndromes, and a genome-wide array-CGH study was applied. The father, the mother, and their daughter were all mentally handicapped with nonspecific clinical manifestations and dysmorphic features. The first child of the family died from multiple congenital anomalies. The father and his daughter, who had never been suspected to have WBS, were diagnosed as having a deletion of the WBS critical region. No other abnormalities were detected in the family. Unlike other previously reported cases, in which the disease was ascertained on the basis of clinical manifestations, the present report represents an example of the detection of cryptic chromosomal abnormalities in mental retardation patients by the stepwise application of high-throughput screening methods. © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins.


Ghaffari S.R.,Foundation Medicine | Ghaffari S.R.,Tehran University of Medical Sciences | Tahmasebpour A.R.,Foundation Medicine | Jamal A.,Foundation Medicine | And 29 more authors.
Ultrasound in Obstetrics and Gynecology | Year: 2012

Objective To investigate the performance of first-trimester screening for chromosomal abnormalities by integrated application of nuchal translucency thickness (NT), nasal bone (NB), tricuspid regurgitation (TR) and ductus venosus (DV) flow combined with maternal serum free β-human chorionic gonadotropin (fβ-hCG) and pregnancy-associated plasma protein-A (PAPP-A) at a one-stop clinic for assessment of risk (OSCAR). Methods In total, 13 706 fetuses in 13 437 pregnancies were screened for chromosomal abnormalities during a period of 5 years. Maternal serum biochemical markers and maternal age were evaluated in combination with NT, NT + NB, NT + NB + TR, and NT + NB + TR + DV flow data in 8581, 242, 236 and 4647 fetuses, respectively. Results In total, 51 chromosomal abnormalities were identified in the study population, including 33 cases of trisomy 21, eight of trisomy 18, six of sex chromosome abnormality, one of triploidy and three of other unbalanced abnormalities. The detection rate and false-positive rate (FPR) for trisomy 21 were 93.8% and 4.84%, respectively, using biochemical markers and NT, and 100% and 3.4%, respectively, using biochemical markers, NT, NB, TR and DV flow. Conclusion While risk assessment using combined biochemical markers and NT measurement has an acceptable screening performance, it can be improved by the integrated evaluation of secondary ultrasound markers of NB, TR and DV flow. This enhanced approach would decrease the FPR from 4.8 % to 3.4 %, leading to a lower number of unnecessary invasive diagnostic tests and subsequent complications, while maintaining the maximum level of detection rate. Pre- and post-test genetic counseling is of paramount importance in either approach. Copyright © 2012 ISUOG.


Ghaffari S.R.,Tehran University of Medical Sciences | Rafati M.,Tehran University of Medical Sciences | Sabokbar T.,Cancer Institute | Dastan J.,Gene Clinic
European Journal of Surgical Oncology | Year: 2010

Aims: Hereditary Diffuse Gastric Cancer (HDGC) is a dominantly inherited familial cancer syndrome resulting from germline mutations of the E-cadherin (CDH1) gene. The first Iranian family with HDGC is herein reported. Methods: The family fulfilled the International Gastric Cancer Linkage Consortium (IGCLC) criteria for HDGC. The entire coding region of the CDH1 gene was analysed by direct sequencing in an obligatory carrier. Subsequent molecular genetic tests were done on other at risk individuals to identify mutation carriers. Results: A novel heterozygous 2275G>T mutation in exon 14 of the CDH1 gene was detected. This nonsense mutation generates a premature stop codon at position 758 giving rise to a truncated E-cadherin protein lacking cytoplasmic region. The specified mutation was detected in the index case and her asymptomatic son who underwent prophylactic gastrectomy. Conclusion: The first Iranian family with HDGC which carries a novel CDH1 germline mutation is reported. © 2010 Elsevier Ltd. All rights reserved.


Ghaffari S.R.,Tehran University of Medical Sciences | Sabokbar T.,Gene Clinic | Sabokbar T.,Tehran University of Medical Sciences | Dastan J.,Gene Clinic | And 2 more authors.
Asian Pacific Journal of Cancer Prevention | Year: 2011

Introduction: Her2/neu is a biomarker which is amplified and/or overexpressed in a subset of breast cancer patients who are eligible to receive trastuzumab. Her-2 gene amplification analysed by fluorescence in situ hybridisation (FISH) and/or protein over-expression detected by immunohistochemistry (IHC) are the two main methods used to detect Her-2 status in clinical practice. The concordance rate between the two techniques is controversial. Methods: FISH analysis were performed on 104 tumoural samples from breast cancer patients with known IHC results to determine the Her2 gene status. The FISH/IHC analyses results were then compared and the concordance rate was determined. Results: Her2 gene amplification was detected in 0 of IHC score 1+, 24/86 (27.91%) 2+, and 8/13 (61.54%) 3+. The IHC and FISH results concordance rates were 100%, 27.9%, and 61.5% for IHC scores of 1+, 2+, and 3+ respectively. Conclusion: The results of this study suggest that IHC 1+ should be considered as negative while IHC 2+ results need further confirmative analysis by FISH. Further quality control and standardization of IHC technique are required to improve the concordance rate between the two methods.

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