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Biomedical subjects

K K Kidd

Publications and source records attributed to K K Kidd.

At least 271 records · Page 15Linked to original sources
PubMed1981

Familial patterns and possible modes of inheritance of primary affective disorders.

A logistic model was used to analyze the pattern of affected relatives of probands with primary affective disorders (PAD). The sample consisted of 242 patients, diagnosed as either unipolar (UP, 107) or bipolar (BP, 135) and 430 control nonpsychiatric inpatients and all first degree relatives of both groups. Age correction was applied to both groups. The analysis showed a significant baseline increase in frequency of PAD among relatives of PAD probands with siblings more likely to be affected than parents. The difference in frequency of PAD according to sex of relative almost reached significance. Specific diagnosis (UP or BP) of proband did not significantly affect the probability of relatives becoming ill. Genetic models incorporating sex-specific thresholds were able to explain the data satisfactorily as resulting from either Single-Major-Locus inheritance or Multifactorial-Polygenic inheritance.

Bipolar Disorder↗
PubMed1981

Analysis of the sibship patterns of stutterers.

Analyses of birth rank, age separation, and the frequency of stutterers in birth ranks before and after the proband were undertaken for the purpose of verifying or disproving conjectures made by other authors on possible relationships between family structures and stuttering. Results based on data drawn from over 300 sibships, showed (a) stutterers were randomly distributed among the birth ranks, (b) the age separation of the siblings was independent of stuttering status, and (c) the frequency of stutterers in birth ranks before the proband and the frequency of stutterers in birth ranks after the proband were not significantly different.

Birth Intervals↗
PubMed1981

Vertical transmission of susceptibility to stuttering with sex-modified expression.

Stuttering is not usually considered genetic, although it has long been known to be familial. Data collected on 2035 relatives of 397 unrelated adult stutterers confirm and quantify the strong familial concentration. Our analytic approach to these family data, one that does not require specification of a genetic hypothesis, shows that stuttering among relatives occurs in a pattern indicating vertical transmission of a susceptibility to stuttering with sex-modified expression. Although simple Mendelian hypotheses are not sufficient to explain the observed pattern of stuttering in families, more complex genetic models can explain the pattern. In the past, such evidence has been considered sufficient, because it does not preclude the possibility of cultural transmission. However, certain cultural transmission hypotheses previously proposed for stuttering are excluded by these data. The findings in this study support a growing opinion among speech pathologists that most stuttering is a genetically inherited neurologic disorder.

Adult↗
PubMed1981

An easy-to-use maximum-likelihood method of estimating the ascertainment probability.

An easy-to-compute statistic for estimating the ascertainment probability is proposed. This statistic is determined through the use of the maximum-likelihood principle and, therefore, in addition to being easy to compute, has the desirable properties of a maximum-likelihood statistic. Variance tables are given to facilitate computation of the estimate and its variance.

Analysis of Variance↗
PubMed1980

Familial pattern of Gilles de la Tourette syndrome.

As part of a pilot questionnaire survey of Gilles de la Tourette syndrome (TS), data on TS and tics for relatives of 75 patients with TS were collected. The frequencies of TS and/or tics among relatives were significantly heterogeneous in a familial pattern that suggests (1) that the disorder is transmitted, with tics alone being a milder manifestation, and that this severity difference is a threshold phenomenon related to transmission; (2) that the sex difference in prevalence is real because it was found among relatives of both male and female probands; and (3) that the sex difference is related to transmission as a threshold effect since female probands, although less common than male probands, had a higher proportion of affected relatives. These pilot data provide evidence for the transmission of TS and can be qualitatively explained by a genetic model of transmission.

Adolescent↗
PubMed1980

Children and depression--the children of depressed parents; the childhood of depressed patients; depression in children.

In order to understand the development of depression in children, three types of data are reviewed: (1) studies of the children of depressed parents; (2) studies of the childhood histories of depressed adults; (3) direct studies of depression in children. These data support an increased frequency of depression and other psychopathology in the children of depressed adults. An examination of the homes of children with a depressed parent reveals a disruptive, hostile, and rejecting environment. This atmosphere is also found in the homes of depressed children and in the homes of children who become depressed as adults. Methodological issues are discussed which will help sort out the relative influences of genes and environment in future studies.

Adolescent↗
PubMed1980

Familial stuttering patterns are not related to one measure of severity.

The possibility of a genetic component to the severity of stuttering was investigated using data on 184 adult stutters and their families. Frequency of stuttering during a pre-treatment oral reading task was used as the severity measure for each of the index cases. Information on whether or not a relative ever stuttered was obtained on all first degree relatives. The family data variables, including sex and exact relationship, combined with birthdate and sex of index case were used in three types of analyses: multiple regressions, AID regressions, and stepwise regressions. None of the variables tested, including stuttering among first degree relatives, was a predictor of severity of stuttering in the index case. We conclude that this measure of severity is not related to the genetic factors which predispose to stuttering.

Adolescent↗
PubMed1980

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↗
PubMed1980

Immunogenetic and population genetic analyses of Iberian cattle.

Blood samples were collected from more than 100 animals in each of 2 Spanish cattle breeds (Retinto and De Lidia), 2 Portuguese breeds (Alentejana and Mertolenga), and American Longhorn cattle. All samples for the 4 Iberian breeds were tested for 20 polymorphic systems; American Longhorn were tested for 19 of the 20. For each breed an average inbreeding coefficient was estimated by a comparison of the observed and expected heterozygosity at 7 or 8 codominant systems tested. All breeds had positive values but only 3 breeds had estimates of inbreeding that were statistically significantly different from 0: De Lidia with f = 0.17, Retinto with f = 0.08 and Mertolenga with f = 0.05. The De Lidia breed especially may be suffering from inbreeding depression since this high value is greater than expected if all of the animals were progeny of half-sib matings. Genetic distances were calculated from the gene frequency data on these 5 breeds plus 9 other European breeds. Analyses of these distances show a closely related group of the 4 Iberian breeds and American Longhorn, confirming the close relationships among the Iberian breeds and the Iberian, probably Portuguese, origin of American Longhorn cattle.

Alleles↗
PubMed1980

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↗
PubMed1980

Genetics of propionic acidemia in a Mennonite-Amish kindred.

A large Mennonite kindred was found to have propionic acidemia (complementation group pcc C) in at least four different sibships. Even within this kindred and this complementation group (where etiology may be assumed to be identical), there is a wide range of symptoms exhibited by homozygous pcc C-deficient individuals. The inbreeding coefficients (f) for the affected sibships ranged from 4.776 X 10(3) to 2.003 X 10(-2). Data from this study strongly support the single-locus autosomal recessive mode of inheritance. Three couples were found to be common in the ancestry (9--11 generations ago) of all eight parents of the four affected sibships. Relative likelihoods for a member of each of those couples to have been the early carrier of the defective allele were calculated at 1539, 278, and 1. Thus, one couple was designated the most likely earliest-known transmitter of the pcc-deficient allele.

Adult↗
PubMed1980

Estimating age-of-onset distributions for disorders with variable onset.

A necessary item of information in many genetic analysis of complex disorders with late onset is the cumulative probability of onset by a given age. The effect of sample design upon the estimation of age-of-onset probability distribution parameters is discussed. Mathematical descriptions of several common sample designs used to estimate the distribution parameters are developed here. Failure to describe the sample space adequately can lead to erroneous genetic analyses because the cumulative probability of onset is incorrectly estimated. In genetic counseling, the errors would usually result in an underestimate of the true risk.

Age Factors↗
PubMed1978

Research designs for the study of gene-environment interactions in psychiatric disorders. Report of a Foundations Fund for Research in Psychiatry Panel.

Understanding the genetic and environmental contributions (and their interactions, which are likely to be complex) to the etiology of psychiatric disorders requires research designs incorporating many basic principles of genetics. Genetic variation is likely to contribute to psychiatric disorders and genetic heterogeneity is likely to exist for any single disorder, ie, completely different genetic variants may each be capable of increasing an individual's susceptibility to the disorder. Thus, it is important to define phenotypes that may more closely reflect each individual genetic variant rather than to rely solely on the psychiatric diagnosis. Research should be undertaken with the goal of testing specific hypotheses that can be excluded. Research designs can include studies of unrelated individuals, twins, separated relatives, nuclear families, or extended pedigrees. Not all hypotheses can be tested on one type of data, and appropriate analytic methods vary. Because genetic hypotheses cannot be tested on studies of unrelated individuals, it is important that data be collected on families instead of unrelated individual patients and/or controls. Studies should include traits that bridge the gap between the genotype and the diagnostic phenotype. Such studies should be multidisciplinary, and the best statistical-genetics methodology should be used for data analysis.

Adoption↗