Biomedical subjects

Laura E Mitchell

Publications and source records attributed to Laura E Mitchell.

21 records · Page 2Linked to original sources

PubMed2002

Molecular analysis of nondisjunction in mice heterozygous for a Robertsonian translocation.

A Robertsonian translocation results in a metacentric chromosome produced by the fusion of two acrocentric chromosomes. Rb heterozygous mice frequently generate aneuploid gametes and embryos, providing a good model for studying meiotic nondisjunction. We intercrossed mice heterozygous for a (7.18) Robertsonian translocation and performed molecular genotyping of 1812 embryos from 364 litters with known parental origin, strain, and age. Nondisjunction events were scored and factors influencing the frequency of nondisjunction involving chromosomes 7 and 18 were examined. We concluded the following: 1. The frequency of nondisjunction among 1784 embryos (3568 meioses) was 15.9%. 2. Nondisjunction events were distributed nonrandomly among progeny. This was inferred from the distribution of the frequency of trisomics and uniparental disomics (UPDs) among all litters. 3. There was no evidence to show an effect of maternal or paternal age on the frequency of nondisjunction. 4. Strain background did not play an appreciable role in nondisjunction frequency. 5. The frequency of nondisjunction for chromosome 18 was significantly higher than that for chromosome 7 in males. 6. The frequency of nondisjunction for chromosome 7 was significantly higher in females than in males. These results show that molecular genotyping provides a valuable tool for understanding factors influencing meiotic nondisjunction in mammals.

Age Factors↗

PubMed2002

Guidelines for the design and analysis of studies on nonsyndromic cleft lip and cleft palate in humans: summary report from a Workshop of the International Consortium for Oral Clefts Genetics.

OBJECTIVE: The members of the International Consortium for Oral Clefts Genetics recognize the need for collaboration between researchers involved in etiologic studies of nonsyndromic cleft lip and palate and cleft palate. To address this need, the consortium established four working subcommittees: diagnostic and phenotypic assessment, molecular genetic studies, epidemiologic data collection and analysis, and genetic data collection and analysis. These subcommittees were charged with the development of guidelines for data collection and analysis that would facilitate both a priori and a posteriori comparisons and pooling of data from multiple centers. This report presents summary statements of the four subcommittees.

Cleft Lip↗

PubMedDate not supplied

Spina bifida.

Spina bifida results from failure of fusion of the caudal neural tube, and is one of the most common malformations of human structure. The causes of this disorder are heterogeneous and include chromosome abnormalities, single gene disorders, and teratogenic exposures. However, the cause is not known in most cases. Up to 70% of spina bifida cases can be prevented by maternal, periconceptional folic acid supplementation. The mechanism underlying this protective effect is unknown, but it is likely to include genes that regulate folate transport and metabolism. Individuals with spina bifida need both surgical and medical management. Although surgical closure of the malformation is generally done in the neonatal period, a randomised clinical trial to assess in utero closure of spina bifida has been initiated in the USA. Medical management is a lifelong necessity for individuals with spina bifida, and should be provided by a multidisciplinary team.

Animals↗