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de Carvalho AFL, Alves ES, Pitanga PML, Ribeiro EM, Doriqui MJR, Toralles MBP, Topázio BA, dos Santos JF, de Lima RLLF, Kulikowski LD, Acosta AX. Identifying Genetic Etiology in Patients with Intellectual Disability: An Experience in Public Health Services in Northeastern Brazil. J Pediatr Genet 2022. [DOI: 10.1055/s-0042-1757888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
AbstractIntellectual disability (ID) is considered a common neuropsychiatric disorder that affects up to 3% of the population. The etiologic origin of ID may be genetic, environmental, and multifactorial. Chromosomopathies are relatively common among the genetic causes of ID, especially in the most severe cases and those associated with dysmorphic features. Currently, the application of new molecular cytogenetics technologies has increasingly allowed the identification of microdeletions, microduplications, and unbalanced translocations as causes of ID. The objective of this study was to investigate the etiology of ID in patients admitted to a public hospital in Northeastern Brazil. In total, 119 patients with ID who had normal karyotypes and fragile X exams participated in this study. The patients were initially physically examined for microdeletion syndromes and then tested using fluorescence in situ hybridization (FISH), multiplex ligation-dependent probe amplification (MLPA), methylation-sensitive polymerase chain reaction (MS-PCR), and chromosome microarray analysis (CMA), according to clinical suspicion. Patients with no diagnoses after FISH, MLPA, and/or MS-PCR evaluations were subsequently tested by CMA. The rate of etiologic diagnoses of ID in the current study was 28%. FISH diagnosed 25 out of 79 tested (31%), MLPA diagnosed 26 out of 79 tested (32%), MS-PCR diagnosed 7 out of 20 tested (35%), and the single nucleotide polymorphism array diagnosed 6 out of 27 tested (22%). Although the CMA is the most complete and recommended tool for the diagnosis of microdeletions, microduplications, and unbalance translocations in patients with ID, FISH, MLPA, and MS-PCR testing can be used as the first tests for specific syndromes, as long as the patients are first physically screened clinically, especially in the public health networks system in Brazil, where resources are scarce.
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Affiliation(s)
| | - Esmeralda Santos Alves
- Laboratory of Human Genetics and Mutagenesis, Institute of Biology, Federal University Bahia (UFBA), Salvador, Bahia, Brazil
| | - Paula Monique Leite Pitanga
- Laboratory of Human Genetics and Mutagenesis, Institute of Biology, Federal University Bahia (UFBA), Salvador, Bahia, Brazil
| | - Erlane Marques Ribeiro
- Faculty of Medicine Estacio of Juazeiro Norte, Estacio-FMJ, Hospital Infantil Albert Sabin, Fortaleza, Ceará, Brazil
| | | | - Maria Betânia Pereira Toralles
- Medical School of Medicine, Medical Genetic Service – Edgard Santos Teaching Hospital/Federal University of Bahia, Salvador, Bahia, Brazil
| | - Bianca Arcaro Topázio
- Laboratory of Human Genetics and Mutagenesis, Institute of Biology, Federal University Bahia (UFBA), Salvador, Bahia, Brazil
| | - Jéssica Fernandes dos Santos
- Laboratory of Human Genetics and Mutagenesis, Institute of Biology, Federal University Bahia (UFBA), Salvador, Bahia, Brazil
| | | | | | - Angelina Xavier Acosta
- Medical School of Medicine, Medical Genetic Service – Edgard Santos Teaching Hospital/Federal University of Bahia, Salvador, Bahia, Brazil
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Hajlaoui A, Slimani W, Kammoun M, Sallem A, El Amri F, Chaieb A, Bibi M, Saad A, Mougou-Zerelli S. Subtelomeric Rearrangements in Patients with Recurrent Miscarriage. INTERNATIONAL JOURNAL OF FERTILITY & STERILITY 2018; 12:218-222. [PMID: 29935067 PMCID: PMC6018184 DOI: 10.22074/ijfs.2018.5260] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 09/27/2017] [Indexed: 11/05/2022]
Abstract
Background The subtelomeric rearrangements are increasingly being investigated in cases of idiopathic intellectual
disabilities (ID) and congenital abnormalities (CA) but are also thought to be responsible for unexplained recurrent
miscarriage (RM). Such rearrangements can go unnoticed through conventional cytogenetic techniques and are undetectable even with high-resolution molecular cytogenetic techniques such as array comparative genomic hybridization
(aCGH), especially when DNA of the stillbirth or families are not available. The aim of the study is to evaluate the rate
of subtelomeric rearrangements in patients with RM. Materials and Methods In this cross-sectional study, fluorescent in situ hybridization (FISH), based on ToTelVysion
telomeric probes, was undertaken for 21 clinically normal couples exhibiting a “normal” karyotype with at least two
abortions. Approximately 62% had RM with a history of stillbirth or CA/ID while the other 38% had only RM. Results FISH detected one cryptic rearrangement between chromosomes 3q and 4p in the female partner of a
couple (III:4) [46,XX,ish t(3;4)(q28-,p16+;p16-,q28+)(D3S4559+,D3S4560-,D4S3359+; D3S4560+, D4S3359-
,D4S2930+)] who presented a history of RM and family history of ID and CA. Analysis of the other family members
of the woman showed that her sisters (III:6 and III:11) and brother (III:8) were also carriers of the same subtelomeric
translocation t(3;4)(q28;p16). Conclusion We conclude that subtelomeric FISH should be undertaken in couples with RM especially those who not
only have abortions but also have had at least one child with ID and/or CA, or other clinically recognizable syndromes.
For balanced and cryptic anomalies, subtelomeric FISH still remains the most suitable and effective tool in characterising such chromosomal rearrangements in RM couples.
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Affiliation(s)
- Amani Hajlaoui
- Department of Cytogenetic and Reproductive Biology, Farhat Hached University Hospital, Sousse, Tunisia
| | - Wafa Slimani
- Department of Cytogenetic and Reproductive Biology, Farhat Hached University Hospital, Sousse, Tunisia
| | - Molka Kammoun
- Department of Cytogenetic and Reproductive Biology, Farhat Hached University Hospital, Sousse, Tunisia
| | - Amira Sallem
- Department of Cytogenetic and Reproductive Biology, Farhat Hached University Hospital, Sousse, Tunisia
| | | | - Anouar Chaieb
- Department of Obstetrics and Gynecology, Farhat Hached University Hospital, Sousse, Tunisia
| | - Mohamed Bibi
- Department of Obstetrics and Gynecology, Farhat Hached University Hospital, Sousse, Tunisia
| | - Ali Saad
- Department of Cytogenetic and Reproductive Biology, Farhat Hached University Hospital, Sousse, Tunisia
| | - Soumaya Mougou-Zerelli
- Department of Cytogenetic and Reproductive Biology, Farhat Hached University Hospital, Sousse, Tunisia. Electronic Address:
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