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K L Garver

Publications and source records attributed to K L Garver.

At least 19 recordsLinked to original sources
PubMed1994

Identity-by-descent and association mapping of a recessive gene for Hirschsprung disease on human chromosome 13q22.

Hirschsprung disease (HSCR) is a congenital disorder of unknown etiology characterized by the absence of enteric ganglia in the distal colon. We have ascertained a large, inbred, Mennonite kindred which demonstrates a high incidence of Hirschsprung disease (HSCR). Genealogical analysis of all kinship relationships identified a single common ancestral couple for all parents of affected offspring. Segregation analysis yielded a segregation ratio of 10.67% for males and 5.45% for females. We searched for locations of the gene(s) responsible for HSCR in this pedigree by genotyping three small multicase families and locating genomic regions demonstrating identity-by-descent followed by linkage disequilibrium analysis of 28 additional nuclear families. Based on this novel strategy, we report the mapping of a new locus for HSCR to chromosome 13q22. Nine microsatellite markers spanning 10 cM in this region were genotyped on thirty-one nuclear families. Significant nonrandom association was detected with alleles at markers D13S162, D13S160, D13S170, and AFM240zg9. In addition, our studies reveal preliminary evidence for a genetic modifier of HSCR in this kindred on chromosome 21q22.

Chromosome Mapping↗
PubMed1994

The Human Genome Project and eugenic concerns.

The U.S. Human Genome project is the largest scientific project funded by the federal government since the Apollo Moon Project. The overall effect from this project should be of great benefit to humankind because it will provide a better understanding both of single gene defects and multifactorial or familial diseases such as diabetes, arteriosclerosis, and cancer. At first this will lead to more exact ways of screening and diagnosing genetic disease, and later it will lead, in many if not most instances, to specific genetic cures. However, in the past, in both the U.S. and German eugenic movements genetic information has been misused. Hopefully, by remembering and understanding the past injustices and inhumanity of negative eugenics, further misuse of scientific information can be avoided.

Ethical Theory↗
PubMed1991

Eugenics: past, present, and the future.

During the past 20 years there has been a resurgence of interest in the history of the eugenics movements, particularly those of the United States and Germany. Unfortunately, most of these accounts have been published in nonmedical and nongenetic journals, so they are not readily available to geneticists or physicians. The authors of this article are concerned about the lack of information that geneticists, physicians, and students have concerning the origin and progress of these movements. This article provides a short history of the American and German eugenics programs and concludes with a review of their possible relations to our current practices. It is hoped that this will encourage institutions to include, in master's Ph.D., and M.D. programs in human genetics, lectures, seminars, and journal clubs on the topic of eugenics.

Ethical Theory↗
PubMed1990

Persistent hyperplastic primary vitreous with vertical transmission.

The authors report a 15-month-old white male and his 30-year-old mother who both have persistent hyperplastic primary vitreous (PHPV) unassociated with other congenital anomalies. Although there are two previous reports of PHPV in siblings suggesting autosomal recessive inheritance, this is the first report compatible with autosomal dominant inheritance.

Adult↗
PubMed1990

A genetic study of Hirschsprung disease.

Hirschsprung disease, or congenital aganglionic megacolon, is commonly assumed to be a sex-modified multifactorial trait. To test this hypothesis, complex segregation analysis was performed on data on 487 probands and their families. Demographic information on probands and the recurrence risk to relatives of probands are presented. An increased sex ratio (3.9 male:female) and an elevated risk to sibs (4%), as compared with the population incidence (0.02%), are observed, with the sex ratio decreasing and the recurrence risk to sibs increasing as the aganglionosis becomes more extensive. Down syndrome was found at an increased frequency among affected individuals but not among their unaffected sibs, and the increase was not associated with maternal age. Complex segregation analysis was performed on these family data. The families were classified into separate categories by extent of aganglionosis. For cases with aganglionosis beyond the sigmoid colon, the mode of inheritance is compatible with a dominant gene with incomplete penetrance, while for cases with aganglionosis extending no farther than the sigmoid colon, the inheritance pattern is equally likely to be either multifactorial or due to a recessive gene with very low penetrance. A model of gene action with random effects during morphogenesis is compatible with our observations.

Female↗
PubMed1988

Monozygotic Turner syndrome twins--correlation of phenotype severity and heart defect.

We report on monozygotic twins with Turner syndrome (45,X) with discordant phenotypes. One twin had severe neck webbing and extremity edema and died of severe coarctation of the aorta. The other twin had fewer craniofacial anomalies and no congenital heart defect, suggesting a pathogenetic relationship between cardiac abnormality and phenotype severity.

Diseases in Twins↗
PubMed1988

Interstitial and terminal deletions of the long arm of chromosome 4: further delineation of phenotypes.

We reviewed 45 patients with a deletion of the long arm of chromosome 4. Forty-one were previous reports (25 terminal deletions and 16 interstitial deletions) and 4 are new cases with terminal deletions. Of the 29 patients with terminal deletions, 18 with deletion at 4q31 and 4 at 4q32----qter had an identifiable phenotype consisting of abnormal skull shape, hypertelorism, cleft palate, apparently low-set abnormal pinnae, short nose with abnormal bridge, virtually pathognomonic pointed fifth finger and nail, congenital heart and genitourinary defects, moderate-severe mental retardation, poor postnatal growth, and hypotonia. Six patients with a deletion at 4q33 and one patient with deletion 4q34 were less severely affected. In general, patients with various interstitial deletions proximal to 4q31 had a phenotype that was less specific, although mental retardation and minor craniofacial anomalies were also present. There were 3 patients with piebaldism and one with Rieger syndrome. We conclude that terminal deletion of chromosome 4q (4q31----qter) appears to produce a distinctive malformation (MCA/MR) syndrome in which the phenotype correlates with the amount of chromosome material missing and which differs from the more variable phenotype associated with interstitial deletions of 4q.

Abnormalities, Multiple↗
PubMed1988

Cardiac abnormalities in neurofibromatosis.

Cardiac abnormalities are potentially important features of neurofibromatosis (NF), but they are rarely discussed in this regard. Several literature reviews have suggested that congenital heart defects (CHD) occur with increased frequency in NF, and several isolated case reports have described hypertrophic cardiomyopathy (HCM) with NF. However, it is not clear whether the occurrence of CHD and HCM in patients with NF is coincidental or representative of an intrinsic, albeit uncommon, manifestation of the disorder. Adequate prospective studies documenting their true prevalence in NF are lacking. As an alternative, we reviewed the available relevant literature and, on that basis, have concluded that there is no clear evidence that CHD occurs with increased frequency among patients with NF, and that no statements can be made about the prevalence of HCM among patients with NF.

Heart Defects, Congenital↗