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| Author(s): |
Milena Simioni
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Faculdade de Ciências Médicas |
| Defense date: | 2008-02-21 |
| Examining board members: |
Vera Lúcia Gil da Silva Lopes;
Carlos Eduardo Steiner;
Elaine Sbroggio de Oliveira Rodini
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| Advisor: | Vera Lúcia Gil da Silva Lopes |
| Abstract | |
Midline Facial Defects with Hipertelorism (MFDH) is a rare and heterogeneous group of craniofacial disorders characterized by ocular hypertelorism and bifid nose. This group of craniofacial defects occurs isolated or as part of a syndrome. For these reasons, its prevalence is still unknown. Alterations in developmental genes involved in facial process could be implicated in the genesis of this condition. The 22q11.2 microdeletion, localization of the HIRA/TUPLE1 and TBX1 genes, causes Velocardiofacial Syndrome and DiGeorge Syndrome. This deletion was also described in few cases of multiple congenital anomalies and MFDH. These facts suggested that some cases of MFDH may be part of the spectrum of these conditions and associated to alterations in the 22q11.2 region. In order to verify this hypothesis, fluorescent in situ hybridization (FISH) for 22q11.2 region (DiGeorge ¿ HIRA/TUPLE1 locus probe, VysisTM) was performed on metaphase chromosomes and nuclei of 10 individuals with MFDH. The 22q11.2 deletion was not found in any patient. Molecular techniques were applied in the study of HIRA/TUPLE1 and TBX1 genes. The amplification of HIRA/TUPLE1 exons was not possible to be realized. Alterations in the sequence of TBX1 gene, classified as single nucleotide polymorphism and a new alteration in exon 9C, 1132G ? A, were found. In view of the size of the sample and the clinical-genetic heterogeneity, we could not associate the involvement of 22q11.2 region in the genesis of MFDH (AU) | |