RESUMO
Previously, we mapped the DFNA52 (OMIM: 607683) locus to an 8.8 cM interval between STR D5S2056 and D5S638 on human chromosome 5q31.1-q32 in a large consanguineous Chinese family with congenital sensorineural hearing loss. Positional candidate cloning approach was applied to analyze the candidate genes in this region. We analyzed 20 genes according to cochlear expression pattern, which were also located in the DFNA52 interval as candidate genes. Sequencing of the coding and splice site regions of these genes did not reveal any potentially pathogenic mutations segregating with the disease, implying that none of these genes are likely virulence gene for DFNA52.
Assuntos
Mapeamento Cromossômico/métodos , Cromossomos Humanos Par 5/genética , Proteínas de Ligação a DNA/genética , Mutação/genética , Sequência de Bases , Feminino , Predisposição Genética para Doença/genética , Perda Auditiva/genética , Humanos , Masculino , Linhagem , Reação em Cadeia da PolimeraseRESUMO
To localize the pathogenic genes of autosomal dominant ichthyosis vulgaris, we ascertained two ichthyosis vulgaris families from Hunan Province. Venous blood samples were collected from affected and unaffected family members and genomic DNA was extracted. We then performed genome scan and linkage analysis using microsatellite markers around known ichthyosis vulgaris loci in chromosomes 1 and 10. In family 1, the locus linked to ichthyosis vulgaris was located near D1S498 (1q21), which overlapped with known ichthyosis vulgaris loci. In family 2, however, all known loci for ichthyosis vulgaris were excluded and the new locus remains to be identified.
Assuntos
Mapeamento Cromossômico/métodos , Ictiose Vulgar/genética , Cromossomos Humanos Par 1/genética , Cromossomos Humanos Par 10/genética , Feminino , Ligação Genética/genética , Humanos , Masculino , Repetições de Microssatélites/genética , LinhagemRESUMO
OBJECTIVE: To identify the MLH1 and MSH2 gene mutation in two hereditary nonpolyposis colorectal cancer (HNPCC) families. METHODS: Polymerase chain reaction and DNA sequencing were used to screen for MLH1 and MSH2 gene mutation, and PCR-restriction fragment length polymorphism and DNA sequencing were performed to confirm the mutation. RESULTS: By DNA sequencing, a novel mutation of c.243_244insA located at the exon 3 of MLH1 gene was detected in family A, while c.1215_1218dupCCGA mutation located at the exon 7 of MSH2 gene was detected in family B. These two mutations can cause the formation of premature proteins. CONCLUSION: The novel mutations c.243_244insA in MLH1 gene and c.1215_1218dupCCGA in MSH2 gene were the disease-causing mutations in the two HNPCC families.