1
|
Ruberto G, Guagliano R, Barillà D, Bensi M, Fazzi E, Galli J, Rossi A, Mazza C, Manzoni F, Domenegati E, Quaranta L. Morpho-functional survey in children suspected of inherited retinal dystrophies via video recording, electrophysiology and genetic analysis. Int Ophthalmol 2020; 40:2523-2534. [PMID: 32507954 DOI: 10.1007/s10792-020-01432-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 05/16/2020] [Indexed: 01/10/2023]
Abstract
PURPOSE To present a detailed study matching functional response and video imaging with genetic analysis in children suspected of inherited retinal dystrophy (IRD). METHODS Sixteen children underwent fundus examination via video recording (Heine Omega 500 indirect ophthalmoscope with DV1 camera) and electroretinogram (ERG) under general anesthesia to investigate the cause of suspected low vision. The patients [median age 12 (interquartile range 8-57.5) months] had associated genetic analysis performed with next-generation sequencing or array-comparative genomic hybridization. RESULTS Four children had potential pathogenic variants in genes involved in Leber congenital amaurosis and Joubert syndrome (NMNAT1, CEP290, KCNJ13, IMPDH1); 1 child had a 16p11.2 microdeletion and 1 in 2q22.1. The ERG was altered in 6 patients, fundus imaging showed serious abnormality matching an IRD in 7 children, and less severe fundus alterations were found in 2 subjects. CONCLUSION Fundus imaging associated with ERG may be significant in IRD diagnosis and visual impairment prognosis, alongside genetic analysis and therapy in selected cases.
Collapse
Affiliation(s)
- Giulio Ruberto
- Ophthalmic Clinic IRCCS San Matteo Hospital, P.zzale Golgi 19, 27100, Pavia, Italy.
| | - Rosanna Guagliano
- Ophthalmic Clinic IRCCS San Matteo Hospital, P.zzale Golgi 19, 27100, Pavia, Italy
| | - Donatella Barillà
- Ophthalmic Clinic IRCCS San Matteo Hospital, P.zzale Golgi 19, 27100, Pavia, Italy
| | - Margherita Bensi
- Ophthalmic Clinic IRCCS San Matteo Hospital, P.zzale Golgi 19, 27100, Pavia, Italy
| | - Elisa Fazzi
- Child Neurology and Psychiatry Unit, ASST Spedali Civili, Brescia, Italy
- Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Jessica Galli
- Child Neurology and Psychiatry Unit, ASST Spedali Civili, Brescia, Italy
- Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Andrea Rossi
- Child Neurology and Psychiatry Unit, ASST Spedali Civili, Brescia, Italy
| | - Cinzia Mazza
- Medical Genetics Laboratory, Department of Pathology, ASST Spedali Civili, Brescia, Italy
| | - Federica Manzoni
- Scientific Direction, Clinical Epidemiology and Biometry Unit, San Matteo Hospital Foundation, Pavia, Italy
| | - Elisa Domenegati
- Department of Anesthesiology and Reanimation, IRCCS San Matteo Hospital, Pavia, Italy
| | - Luciano Quaranta
- Ophthalmic Clinic IRCCS San Matteo Hospital, P.zzale Golgi 19, 27100, Pavia, Italy
| |
Collapse
|
2
|
Naseer MI, Rasool M, Chaudhary AG, Sogaty S, Karim S, Schulten HJ, Bibi F, Pushparaj PN, Algahtani HA, Al-Qahtani MH. Chromosomal Micro-aberration in a Saudi Family with Juvenile Myoclonic Epilepsy. CNS Neurol Disord Drug Targets 2019; 16:1010-1017. [PMID: 28758580 DOI: 10.2174/1871527316666170731103509] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 08/04/2016] [Accepted: 07/25/2017] [Indexed: 11/22/2022]
Abstract
BACKGROUND AND OBJECTIVE Epilepsy is etiologically and genetically complex neurological disorder affecting millions of people worldwide. Juvenile myoclonic epilepsy (JME) is the most common epilepsy syndrome that starts in the teen age group commonly between ages 12, 18, and lasts till adulthood. One out of fourteen people with epilepsy suffers with JME. Myoclonic seizures and muscle twitching or uncontrolled jerking are the most common type of seizures in the people suffering with JME. METHOD To observe the novel CNVs involved in JME, we investigated a Saudi family with nine siblings including one male and one female affected members. In this study we used high density whole genome Agilent sure print G3 Hmn CGH 2x 400K array-CGH chips. Our results showed CNVs including the amplifications and deletions in different chromosomal regions in the patients as compared to the normal members of the family. Amplifications were observed in the chromosome 22 cytoband 22q11.23 with LDL receptor related protein 5 like (LRP5L), Immunoglobulin Lambda-Like Polypeptide 3 (IGLL3) and crystallin beta B2 pseudogene (CRYBB2P) genes respectively whereas the deletions were observed in the chromosomal regions 4q22.2 with Glutamate receptor, ionotropic, delta 2 (GRID2) as potential gene cytoband 1p31.1 with potential Neuronal Growth Regulator 1 gene (NEGR1) gene in this region and NME/NM23 family member (NME7) gene cytoband 1q24. Moreover, the array CGH resulting in deletions and duplication were also validated by using primer for simple PCR or also by using quantitative real time PCR analysis. We found deletions and duplication in JME patients in our study for the first time in Saudi population. RESULTS & CONCLUSION The findings in this study suggest that the array-CGH may be considered as a first line of genetic testing for diagnosis of epilepsy unless strong evidence is presented for a monogenic syndrome. The use of high throughput technique in this study will help to identify novel mechanisms underlying epileptic disorder in order to lower the burden of epilepsy in Saudi Arabia.
Collapse
Affiliation(s)
- Muhammad Imran Naseer
- Center of Excellence in Genomic Medicine Research, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Mahmood Rasool
- Center of Excellence in Genomic Medicine Research, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Adeel G Chaudhary
- Center of Excellence in Genomic Medicine Research, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Sameera Sogaty
- Department of Medical Genetics, King Fahad General Hospital, Jeddah, Saudi Arabia
| | - Sajjad Karim
- Center of Excellence in Genomic Medicine Research, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Hans-Juergen Schulten
- Center of Excellence in Genomic Medicine Research, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Fehmida Bibi
- King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Peter Natesan Pushparaj
- Center of Excellence in Genomic Medicine Research, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Hussein A Algahtani
- King Saud bin Abdulaziz University for Health Sciences, Jeddah, Saudi Arabia
| | - Mohammad H Al-Qahtani
- Center of Excellence in Genomic Medicine Research, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| |
Collapse
|
3
|
Sim J, Nam DH, Kim Y, Lee IH, Choi JW, Sa JK, Suh YL. Comparison of 1p and 19q status of glioblastoma by whole exome sequencing, array-comparative genomic hybridization, and fluorescence in situ hybridization. Med Oncol 2018; 35:60. [PMID: 29600313 DOI: 10.1007/s12032-018-1119-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 03/23/2018] [Indexed: 12/30/2022]
Abstract
According to the 2016 World Health Organization classification of tumors of the central nervous system, detecting 1p/19q co-deletion became essential in clinical neuropathology for gliomas with oligodendroglioma-like morphology. Here, we assessed genomic profiles of glioblastoma in 80 cases including 1p/19q status using fluorescent in situ hybridization (FISH), array-comparative genomic hybridization (aCGH), and/or whole exome sequencing (WES). Paraffin-embedded tumor tissues were subjected to FISH analysis, and the corresponding frozen tissues from the same tumors were evaluated for aCGH and/or WES for 1p/19q co-deletion and other genetic parameters, which included IDH1-R132H, ATRX, TP53, CIC, and NOTCH1 mutations and MGMT methylation status. We also evaluated correlations between 1p/19q co-deletion status and molecular markers or clinical outcomes. The FISH analyses revealed 1p/19q co-deletion in two cases, isolated deletion of 1p in six cases, and 19q in two cases, whereas the aCGH and WES results showed isolated deletion of 19q in four cases and 19 monosomy in only one case. Eleven cases showed discordant 1p/19q results between aCGH/WES and FISH analysis, and in most of them, 1p and/or 19q deletion on FISH analysis corresponded to the partial deletions at 1p36 and/or 19q13 on aCGH/WES. Our cohort exhibited IDH1-R132H mutations (5.4%), MGMT promotor methylation (34.6%), and mutations in ATRX (9.5%), TP53 (33.3%), and NOTCH1 (3.8%) but not in CIC (0%). In addition, MGMT methylation and ATRX mutation were significantly associated with clinical prognosis. In glioblastomas, partial deletions of 1p36 and/or 19q13 were uncommon, some of which appeared as 1p and/or 19q deletions on FISH analysis.
Collapse
|
4
|
Nishigaki S, Hamazaki T, Saito M, Yamamoto T, Seto T, Shintaku H. Periventricular heterotopia and white matter abnormalities in a girl with mosaic ring chromosome 6. Mol Cytogenet 2015. [PMID: 26213576 PMCID: PMC4514952 DOI: 10.1186/s13039-015-0162-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Ring chromosome 6 is a rare chromosome abnormality that arises typically de novo. The phenotypes can be highly variable, ranging from almost normal to severe malformations and neurological defects. We report a case of a 3-year-old girl with mosaic ring chromosome 6 who presented with being small for gestational age and intellectual disability, and whose brain MRI later revealed periventricular heterotopia and white matter abnormalities. Mosaicism was identified in peripheral blood cells examined by standard G-bands, mos 46,XX,r(6)(p25q27)[67]/45,XX,-6[25]/46,XX,dic r(6:6)(p25q27:p25q27)[6]/47,XX,r(6)(p25q27) × 2[2]. Using array-comparative genomic hybridization, we identified terminal deletion of 6q27 (1.5 Mb) and no deletion on 6p. To our knowledge, this is the first report of periventricular heterotopia and white matter abnormalities manifested in a patient with ring chromosome 6. These central nervous system malformations are further discussed in relation to molecular genetics.
Collapse
Affiliation(s)
- Satsuki Nishigaki
- Department of Pediatrics, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka, 545-8585 Japan
| | - Takashi Hamazaki
- Department of Pediatrics, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka, 545-8585 Japan
| | - Mika Saito
- Department of Pediatrics, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka, 545-8585 Japan
| | - Toshiyuki Yamamoto
- Institute for Integrated Medical Sciences, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ward, Tokyo, 162-8666 Japan
| | - Toshiyuki Seto
- Department of Pediatrics, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka, 545-8585 Japan
| | - Haruo Shintaku
- Department of Pediatrics, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka, 545-8585 Japan
| |
Collapse
|
5
|
Armanet N, Metay C, Brisset S, Deschenes G, Pineau D, Petit FM, Di Rocco F, Goossens M, Tachdjian G, Labrune P, Tosca L. Double Xp11.22 deletion including SHROOM4 and CLCN5 associated with severe psychomotor retardation and Dent disease. Mol Cytogenet 2015; 8:8. [PMID: 25670966 PMCID: PMC4322561 DOI: 10.1186/s13039-015-0107-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 01/08/2015] [Indexed: 11/23/2022] Open
Abstract
Background Here we report the clinical and molecular characterization of two Xp11.22 deletions including SHROOM4 and CLCN5 genes. These deletions appeared in the same X chromosome of the same patient. Results The patient is a six-year-old boy who presented hydrocephalus, severe psychomotor and growth retardation, facial dysmorphism and renal proximal tubulopathy associated with low-molecular-weight proteinuria, hypercalciuria, hyperaminoaciduria, hypophosphatemia and hyperuricemia. Standard and high resolution karyotypes showed a 46,XY formula. Array-CGH revealed two consecutive cryptic deletions in the region Xp11.22, measuring respectively 148 Kb and 2.6 Mb. The two deletions were inherited from the asymptomatic mother. Conclusions Array-CGH allowed us to determine candidate genes in the deleted region. The disruption and partial loss of CLCN5 confirmed the diagnostic of Dent disease for this patient. Moreover, the previously described involvement of SHROOM4 in neuronal development is discussed.
Collapse
Affiliation(s)
- Narjes Armanet
- Service d'Histologie, Embryologie et Cytogénétique, Hôpitaux Universitaires Paris-Sud. Hôpital Antoine Béclère, 157 rue de la Porte de Trivaux, 92141, Clamart, F-92140 France.,Université Paris-Sud, Le Kremlin-Bicêtre, F-94276 France
| | - Corinne Metay
- Plateforme de Génomique IMRB 955, Hôpital Henri Mondor, Créteil, F-94010 France
| | - Sophie Brisset
- Service d'Histologie, Embryologie et Cytogénétique, Hôpitaux Universitaires Paris-Sud. Hôpital Antoine Béclère, 157 rue de la Porte de Trivaux, 92141, Clamart, F-92140 France.,Université Paris-Sud, Le Kremlin-Bicêtre, F-94276 France
| | - Georges Deschenes
- Service de Néphrologie pédiatrique, Hôpital Robert Debré, Paris, F-75935 France
| | - Dominique Pineau
- Service d'Histologie, Embryologie et Cytogénétique, Hôpitaux Universitaires Paris-Sud. Hôpital Antoine Béclère, 157 rue de la Porte de Trivaux, 92141, Clamart, F-92140 France
| | - François M Petit
- Laboratoire de Génétique Moléculaire, Hôpitaux Universitaires Paris-Sud. Hôpital Antoine Béclère, Clamart, F-92140 France
| | - Federico Di Rocco
- Service de Neurochirurgie pédiatrique, Hôpital Necker Enfants Malades, Clamart, F-75015 France
| | - Michel Goossens
- Plateforme de Génomique IMRB 955, Hôpital Henri Mondor, Créteil, F-94010 France.,Université Paris Est, Créteil, F-94010 France
| | - Gérard Tachdjian
- Service d'Histologie, Embryologie et Cytogénétique, Hôpitaux Universitaires Paris-Sud. Hôpital Antoine Béclère, 157 rue de la Porte de Trivaux, 92141, Clamart, F-92140 France.,Université Paris-Sud, Le Kremlin-Bicêtre, F-94276 France
| | - Philippe Labrune
- Université Paris-Sud, Le Kremlin-Bicêtre, F-94276 France.,Service de Pédiatrie, Hôpitaux Universitaires Paris-Sud. Hôpital Antoine Béclère, Clamart, F-92140 France
| | - Lucie Tosca
- Service d'Histologie, Embryologie et Cytogénétique, Hôpitaux Universitaires Paris-Sud. Hôpital Antoine Béclère, 157 rue de la Porte de Trivaux, 92141, Clamart, F-92140 France.,Université Paris-Sud, Le Kremlin-Bicêtre, F-94276 France
| |
Collapse
|
6
|
Tarsitano M, Ceglia C, Novelli A, Capalbo A, Lombardo B, Pastore L, Fioretti G, Vicari L, Pisanti MA, Friso P, Cavaliere ML. Microduplications in 22q11.2 and 8q22.1 associated with mild mental retardation and generalized overgrowth. Gene 2013; 536:213-6. [PMID: 24315824 DOI: 10.1016/j.gene.2013.11.051] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Revised: 11/04/2013] [Accepted: 11/22/2013] [Indexed: 12/21/2022]
Abstract
The 22q11.2 microduplication is a genomic disorder, characterized from a variable phenotype ranging from different defects to normality. The most common microduplication of 22q11.2 is 3 Mb in size, but there are also cases reported with atypical duplications between 0.8 Mb and 6Mb. Here, we describe a case of a child with macrocephaly, overgrowth with advanced bone age, attention deficits, evidence of mild mental retardation and dysmorphic features. An array-CGH analysis detected a 252 Kb duplication at the 22q11.2 region inherited from mother and 142 Kb duplication at 8q22.1 region inherited from father. Both parents show mild dysmorphic features. The duplicated genes in chromosomes 22q and 8q are TOP3B and PGCP, respectively. We describe for the first time a patient carrying the smaller atypical 22q11.2 duplication who also presents with mild mental retardation and generalized overgrowth. This patient has an additional duplication in 8q22.1 which may act as a genomic modifier of its clinical phenotype.
Collapse
Affiliation(s)
| | - Carlo Ceglia
- CEINGE Advanced Biotechnology, S.c.a.r.l., Naples, Italy
| | - Antonio Novelli
- Mendel Laboratory, Casa Sollievo della Sofferenza IRCCS, Viale Regina Margherita 261, 00198 Rome, Italy
| | - Anna Capalbo
- Mendel Laboratory, Casa Sollievo della Sofferenza IRCCS, Viale Regina Margherita 261, 00198 Rome, Italy
| | - Barbara Lombardo
- CEINGE Advanced Biotechnology, S.c.a.r.l., Naples, Italy; Department Biochemistry and Medical Biotechnology, University of Naples "Federico II", Naples, Italy
| | - Lucio Pastore
- CEINGE Advanced Biotechnology, S.c.a.r.l., Naples, Italy; Department Biochemistry and Medical Biotechnology, University of Naples "Federico II", Naples, Italy
| | | | - Laura Vicari
- Service of Medical Genetics, Cardarelli Hospital, Naples, Italy
| | | | - Patrizia Friso
- Service of Medical Genetics, Cardarelli Hospital, Naples, Italy
| | | |
Collapse
|
7
|
Saleem R, Setty G, Hussain N. MICrocephaly, disproportionate pontine and cerebellar hypoplasia syndrome: A clinico-radiologic phenotype linked to calcium/calmodulin-dependent serine protein kinase gene mutation. Indian J Hum Genet 2013; 19:104-7. [PMID: 23901204 PMCID: PMC3722619 DOI: 10.4103/0971-6866.112921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
MICrocephaly, disproportionate pontine and cerebellar hypoplasia (MICPCH) syndrome, a rare X-linked disorder, generally seen in girls, is characterized by neurodevelopmental delay, microcephaly, and disproportionate pontine and cerebellar hypoplasia. It is caused by inactivating calcium/calmodulin-dependent serine protein kinase (CASK) gene mutations. We report a 2-year-old girl with severe neurodevelopmental delay, microcephaly, minimal pontine hypoplasia, cerebellar hypoplasia, and normal looking corpus callosum, with whom the conventional cytogenetic studies turned out to be normal, and an array-comparative genomic hybridization (a-CGH) analysis showed CASK gene duplication at Xp11.4. Our case highlights the importance of using clinico-radiologic phenotype to guide genetic investigation and it also confirms the role of a-CGH analysis in establishing the genetic diagnosis of MICPCH syndrome, when conventional cytogenetic studies are inconclusive.
Collapse
Affiliation(s)
- Rashid Saleem
- Department of Pediatric Neurology, Leicester Royal Infirmary, University Hospitals of Leicester NHS Trust, United Kingdom
| | | | | |
Collapse
|
8
|
Rooryck C, Toutain J, Cailley D, Bouron J, Horovitz J, Lacombe D, Arveiler B, Saura R. Prenatal diagnosis using array-CGH: a French experience. Eur J Med Genet 2013; 56:341-5. [PMID: 23454632 DOI: 10.1016/j.ejmg.2013.02.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Accepted: 02/07/2013] [Indexed: 01/19/2023]
Abstract
Array-CGH or Chromosomal Microarray Analysis (CMA) is increasingly used in prenatal diagnosis throughout the world. However, routine practices are very different among centers and countries, regarding CMA indications, design and resolution of microarrays, notification and interpretation of Copy Number Alterations (CNA). We present our data and experience from our Fetal Medicine Center on 224 prospective prenatal diagnoses. Our approach is practical, and aims to propose a strategy to offer Chromosomal Microarray Analysis (CMA) to selected fetuses and to help to interpret CNA. We hope that this publication could encourage development of CMA in centers that have not started yet this activity in prenatal routine, and could contribute to edict guidelines in this field.
Collapse
|
9
|
Lau EC. Preimplantation testing: Transition from genetic to genomic diagnosis. World J Med Genet 2012; 2:9-14. [DOI: 10.5496/wjmg.v2.i2.9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Preimplantation genetic testing refers to the procedure to determine the genetic status of embryos formed by in vitro fertilization (IVF) prior to initiating a pregnancy. Traditional genetic methods for preimplantation genetic diagnosis (PGD) examine distinct parts of an individual genome, require the development of a custom assay for every patient family, and are time consuming and inefficient. In the last decade technologies for whole-genome amplification (WGA) from single cells have led to innovative strategies for preimplantation testing. Applications of WGA technology can lead to a universal approach that uses single-nucleotide polymorphisms (SNPs) and mutations across the entire genome for the analysis. Single-cell WGA by multiple displacement amplification has enabled a linkage approach to PGD known as “preimplantation genetic haplotyping”, as well as microarray-based techniques for preimplantation diagnosis. The use of microarrays in preimplantation diagnosis has provided genome-wide testing for gains or losses of single chromosomes (aneuploidies) or chromosomal segments. Properly designed randomized controlled trials are, however, needed to determine whether these new technologies improve IVF outcomes by increasing implantation rates and decreasing miscarriage rates. In genotype analysis of single cells, allele dropout occurs frequently at heterozygous loci. Preimplantation testing of multiple cells biopsied from blastocysts, however, can reduce allele dropout rates and increase the accuracy of genotyping, but it allows less time for PGD. Future development of fast SNP microarrays will enable a universal preimplantation testing for aneuploidies, single-gene disorders and unbalanced translocations within the time frame of an IVF cycle.
Collapse
|