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Biomedical subjects

L A Morton

Publications and source records attributed to L A Morton.

5 recordsLinked to original sources

Risks of affective illness among first-degree relatives of bipolar I old-order Amish probands.

Data from bipolar I old-order Amish families suggest that the morbid risk of illness is not significantly different in this population when compared with estimates of risk from previous studies. The age-corrected rates of bipolar I, bipolar II, and major depressive disorder among first-degree relatives are 8.7, 3.7, and 11.6, respectively. Risk of illness is not significantly different among male and female relatives and among relatives of male and female probands. Consistent with other reports, the rate of illness is higher among relatives of probands with early-onset disease. In contrast with previous reports, there does not appear to be a cohort effect in this population.

Adolescent↗

The effects of variable age-of-onset and diagnostic criteria on the estimates of linkage: an example using manic-depressive illness and color blindness.

Three pedigrees were selected from the literature for their compatibility with the hypothesis of linkage between the X-chromosome marker color blindness and bipolar affective disorder. We compared the results of linkage analyses of these pedigrees when both penetrance function and diagnostic classification were varied. The analyses show that the incorporation of age-of-onset information into a penetrance function significantly increased the evidence for linkage. In addition, assumptions about diagnostic classification affected the lod scores. These results demonstrate the need for careful consideration of diagnostic criteria and variable age-of-onset when pursuing linkage analysis of complex traits.

Bipolar Disorder↗

Probable linkage between the human galactose-1-P uridyl transferase locus and 9qh.

Evaluation of a family in which electrophoretic variants of the eznyme galactose-1-phosphate uridyl transferase (GALT) and 9qh variants occur demonstrates close linkage between these two traits: lod score of 3.67 at theta = 0. Taken with information indicating GALT is on the short arm of chromosome 9, these linkage data suggest that this locus is close to the centromere on the short arm of chromosome 9.

Blood Protein Electrophoresis↗