RESUMO
<p><b>OBJECTIVE</b>To determine the origin of chromosomal aberration for a girl with mental retardation and multiple congenital deformities.</p><p><b>METHODS</b>The karotypes of the girl and her parents were analyzed with routine G-banding .Their genomic DNA was also analyzed with array comparative genomic hybridization (aCGH). Short tandem repeats (STR) were used to confirm the results of aCGH.</p><p><b>RESULTS</b>There were no karyotypic abnormality detected at cytogenetic level. aCGH identified a de novo 1.28 Mb deletion at 2p15-p16.1 in the girl. The results of the STR confirmed the deletion affected the maternal chromosome.</p><p><b>CONCLUSION</b>The de novo interstitial 2p15-p16.1 deletion may cause the mental retardation and multiple congenital deformities. chr2:60.5-61.5 Mb may be the minimal common region of 2p15-p16.1 microdeletion syndrome.</p>
Assuntos
Adolescente , Feminino , Humanos , Anormalidades Múltiplas , Diagnóstico , Genética , Bandeamento Cromossômico , Deleção Cromossômica , Transtornos Cromossômicos , Diagnóstico , Genética , Cromossomos Humanos Par 2 , Genética , Hibridização Genômica Comparativa , Métodos , Deficiência Intelectual , Diagnóstico , Genética , Repetições de Microssatélites , Genética , Fenótipo , SíndromeRESUMO
<p><b>OBJECTIVE</b>To identify the gene causing hereditary multiple exostoses in a Chinese pedigree.</p><p><b>METHODS</b>Linkage analysis was carried out in the family using microsatellite markers close linkage to the EXT1 and EXT2 genes to define the candidate gene. Then the whole coding sequence and the intron-exon boundaries of the candidate gene were amplified and sequenced.</p><p><b>RESULTS</b>The disease-causing gene of the family was linked to the EXT2 gene. A nonsense mutation of 536G>A in exon3 of the EXT2 gene was detected, which was co-segregated with the disease phenotype. The mutation resulted in a stop codon in codon 180. A nonpenetrant case was found in the family.</p><p><b>CONCLUSION</b>The mutation 536G>A in the EXT2 gene is the disease-causing mutation in the pedigree with hereditary multiple exostoses.</p>
Assuntos
Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Adulto Jovem , Povo Asiático , Genética , Sequência de Bases , China , Códon sem Sentido , Exostose Múltipla Hereditária , Genética , Dados de Sequência Molecular , N-Acetilglucosaminiltransferases , Genética , LinhagemRESUMO
ObjectiveTo investigate the molecular pathogenesis of a pedigree of X-linked spondyloepiphyseal dysplasia atarda (SEDL) and to establish methods of gene diagnosis. Methods Clinical diagnosis was made based on height measurement, radiological examination and pedigree analysis. Peripheral blood samples of relevant family members were collected. After genomic DNA extraction, single strand conformation polymorphism (SSCP) followed with DNA sequencing was used to detect SEDL gene exons 36. Microsatellite marker DXS16 was selected for linkage analysis. Results The abnormal electrophoretic bands were detected in exon 4 of probands by PCR-SSCP. A c. 218C ＞ T mutation in exon 4 of SEDL gene was found in three probands, which resulted in a change in amino acid sequence S37L. The heterozygous exon 4 mutation was identified in three carriers, but not in healthy individuals, and no mutations were detect in exon 3, 5 and 6 of probands. Three unmarried young females (Ⅲ10, Ⅳ6 and Ⅳ7) were found to harbor the mutation by DNA sequencing analysis. ConclusionsA c. 218C ＞ T missense mutation in exon 4 of SEDL gene is the cause of molecular pathogenesis of the pedigree. SSCP and DNA sequencing can be used for prenatal gene diagnosis.