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Biomedical subjects

W J Kimberling

Publications and source records attributed to W J Kimberling.

At least 19 recordsLinked to original sources
PubMed1995

Quantitative trait locus for reading disability: correction.

In the news article "Can risky mergers save hospital-based research?" by Wade Roush (19 May, p. 968), the statement that University Hospitals of Cleveland rose from 20th in the rankings of teaching hospitals funded by the National Institutes of Health (NIH) in 1991 to 12th at present was incorrect. In fact, it was Case Western Reserve University (CWRU), with which University Hospitals of Cleveland is affiliated, that received $69 million in NIH grants in 1993, making it the 20th largest recipient of such grants among medical centers; the university then received $97 million in 1994, raising its rank to 12th. About $15 million of the increase, or 53%, was attributable to CWRU's 1992 affiliation with Henry Ford Hospital in Detroit. Other hospitals affiliated with Case Western include MetroHealth Medical Center, Mount Sinai Medical Center, St. Luke's Medical Center, and Cleveland Veterans' Affairs Medical Center.

Chromosome Mapping↗
PubMed1995

Cardiovascular abnormalities in children with autosomal dominant polycystic kidney disease.

It is known that adults with autosomal dominant polycystic kidney disease (ADPKD) have an increased incidence of cardiovascular abnormalities, including mitral valve prolapse. The cardiac manifestations of ADPKD in the pediatric population have not been well established. To determine the cardiac manifestations of children with ADPKD, echocardiography was performed in 154 children of 66 families in which one parent has ADPKD. Eighty-six affected children and 68 unaffected children were evaluated in a prospective, single-blinded manner by echocardiography. Affected children were defined as those with any cysts on a concurrent renal ultrasound or those predicted to be gene carriers by gene linkage analysis. A 12% incidence of mitral valve prolapse was found in the affected children compared with only 3% of the unaffected children (P < 0.05). ADPKD children, but not their unaffected siblings, demonstrate a significant correlation between left ventricular mass index and systolic blood pressure. Moreover, hypertensive ADPKD children have significantly larger left ventricular mass index than do normotensive ADPKD children. A 3.5% incidence of congenital heart disease was found in the affected group, whereas 2.9% of the unaffected children had congenital heart disease. It was concluded that systemic manifestations of ADPKD, particularly cardiovascular abnormalities, are present even in childhood and these warrant the clinician's attention.

Abnormalities, Multiple↗
PubMed1995

Clinical and molecular genetics of Usher syndrome.

Usher syndrome is an autosomal-recessive disorder manifested by hearing impairment, retinitis pigmentosa (RP), and variable vestibular deficit. Recent progress in the characterization of the genetics of Usher syndrome has shown that this disorder is phenotypically and genetically complex. This progress impacts the approach of the clinicians in the study of patients who may potentially have Usher syndrome. There are three major phenotypic classes: Usher I, II, and III. Usher I is distinguished from Usher II by having a more severe audiologic involvement and by the presence of vestibular areflexia. Usher III has a progressive hearing loss with variable vestibular involvement. A minimum of three genes have been identified as being responsible for Usher I; two have been identified as being responsible for Usher II. It is not yet clear whether other manifestations such as progressive hearing loss, associated mental retardation, or other physical anomalies are associated with the known Usher genes or whether they represent as yet undiscovered genetic disorders. As progress towards the identification of the Usher genes is made, the clinician will gradually gain new and effective diagnostic procedures for the identification and delineation of the Usher syndromes.

Adult↗
PubMed1995

Gene mapping of Usher syndrome type IIa: localization of the gene to a 2.1-cM segment on chromosome 1q41.

Usher syndrome type II is associated with hearing loss and retinitis pigmentosa but not with any vestibular problems. It is known to be genetically heterogeneous, and one locus (termed USH2A) has been linked to chromosome 1q41. In an effort to refine the localization of USH2A, the genetic map of the region between and adjacent to the marker loci previously recognized as flanking USH2A (D1S70 and PPOL) is updated. Analysis of marker data on 68 Usher II families places the USH2A gene into a 2.1-cM region between the markers D1S237 and D1S229. The gene for transforming growth factor beta 2 (TGFB2) and the gene for the homeodomain box (HLX1) are both eliminated as candidates for USH2A, by virtue of their localization outside these flanking markers. The earlier finding of genetic heterogeneity was confirmed in six new families, and the proportion of unlinked Usher II families is estimated at 12.5%. The placement of the USH2A gene into this region will aid in the physical mapping and isolation of the gene itself.

Chromosome Mapping↗
PubMed1994

Quantitative trait locus for reading disability on chromosome 6.

Interval mapping of data from two independent samples of sib pairs, at least one member of whom was reading disabled, revealed evidence for a quantitative trait locus (QTL) on chromosome 6. Results obtained from analyses of reading performance from 114 sib pairs genotyped for DNA markers localized the QTL to 6p21.3. Analyses of corresponding data from an independent sample of 50 dizygotic twin pairs provided evidence for linkage to the same region. In combination, the replicate samples yielded a chi 2 value of 16.73 (P = 0.0002). Examination of twin and kindred siblings with more extreme deficits in reading performance yielded even stronger evidence for a QTL (chi 2 = 27.35, P < 0.00001). The position of the QTL was narrowly defined with a 100:1 confidence interval to a 2-centimorgan region within the human leukocyte antigen complex.

Adolescent↗
PubMed1994

Linkage of autosomal dominant hearing loss to the short arm of chromosome 1 in two families.

BACKGROUND: At least half of the cases of profound deafness of early onset are caused by genetic factors, but few of the genetic defects have been identified. This is particularly true of the most common hereditary forms of deafness, which occur in the absence of any associated syndrome. METHODS: We studied a large Indonesian family in which hearing loss was inherited in an autosomal dominant pattern. The hearing loss first affects the high frequencies during the teens or 20s and becomes profound within 10 years. To locate the responsible gene, we performed genetic-linkage analysis, using microsatellite markers distributed over the entire genome. We then performed linkage analyses in an American family and a Dutch family with similar patterns of hereditary hearing loss. RESULTS: In the extended Indonesian family, a gene linked to deafness mapped to chromosome 1p, with a multipoint lod score of more than 7. In the American family, deafness was linked to the same locus on chromosome 1p, with a multipoint lod score of more than 5. In the Dutch family, however, this locus was ruled out. The flanking markers D1S255 and D1S211 defined a region of 6 cM on chromosome 1p that is likely to contain the gene associated with deafness in the first two families. CONCLUSIONS: In some families with early-onset autosomal dominant hearing loss, the responsible gene is on chromosome 1p.

Adolescent↗
PubMed1994

Clinical diagnosis of the Usher syndromes. Usher Syndrome Consortium.

The Usher syndromes are genetically distinct disorders which share specific phenotypic characteristics. This paper describes a set of clinical criteria recommended for the diagnosis of Usher syndrome type I and Usher syndrome type II. These criteria have been adopted by the Usher Syndrome Consortium and are used in studies reported by members of this Consortium.

Diagnosis, Differential↗
PubMed1994

Refining the region of branchio-oto-renal syndrome and defining the flanking markers on chromosome 8q by genetic mapping.

Branchio-oto-renal syndrome (BOR) is an autosomal dominant disorder associated with external-, middle-, and inner-ear malformations, branchial cleft sinuses, cervical fistulas, mixed hearing loss, and renal anomalies. The gene for BOR was mapped to the long arm of chromosome 8q. Several polymorphic dinucleotide repeat markers were investigated for linkage in two large BOR families, and the region of localization was refined. Two-point linkage analysis yielded the maximum lod scores of 7.44 at theta = .03 and 6.71 at theta = .04, with markers D8S279 and D8S260, respectively. A multipoint analysis was carried out to position the BOR gene with a defined region using markers D8S165, D8S285, PENK, D8S166, D8S260, D8S279, D8S164, D8S286, D8S84, D8S275, D8S167, D8S273, and D8S271. Haplotype analysis of recombination events at these polymorphic loci was also performed in multigeneration BOR kindreds. The linkage analysis and analysis of recombination events identified markers that clearly flank the BOR locus. The order was determined to be D8S260-BOR-D8S279 at odds > 10(3):1 over the other possible orders. This flanking markers provide a resource for high-resolution mapping toward cloning and characterizing the BOR gene.

Abnormalities, Multiple↗
PubMed1993

Mutation analysis and haplotype correlation for 139 cystic fibrosis patients from the Nebraska Regional Cystic Fibrosis Center.

Cystic fibrosis (CF) is the most common autosomal recessive disorder in Caucasian populations with an approximate frequency of one in 2,500 live births and a carrier frequency of one in 25. We studied 400 individuals seen at The Nebraska Regional Cystic Fibrosis Center that included 139 CF patients, 206 parents, and 55 unaffected siblings to determine the frequency of the delta F508, R117H, G542X, S549R/N, G551D, R553X, R560T, and W1282X mutations. In addition, we determined haplotypes on each of these individual's chromosomes using four markers that included XV-2c, KM-19, pMP6d.9, and G2. Results from this study showed that the delta F508 mutation was present in 70% of CF chromosomes. Of the 139 CF patients 74 (53%) were homozygous for the delta F508 deletion, 47 (34%) were heterozygous for the delta F508 deletion and an unknown mutation, and 18 (13%) carried two unknown mutations. Four additional mutations were also found in our population and included G542X (6%), G551D (5%), R553X (4%), and R560T (1%). One patient was documented to be a compound heterozygote for G542X/G551D. A polymorphism, F508C, that has previously been reported in several families was also present in our study. The most common haplotype associated with the delta F508 deletion in our CF patients was the E haplotype (CF Consortium B) while other mutations were associated with a variety of haplotypes.

Base Sequence↗
PubMed1993

Genetic heterogeneity of Usher syndrome type II.

Usher syndrome is an autosomal recessive disorder characterised by retinitis pigmentosa and congenital sensorineural hearing loss. A gene for Usher syndrome type II (USH2) has been localised to chromosome 1q32-q41. DNA from a family with four of seven sibs affected with clinical characteristics of Usher syndrome type II was genotyped using markers spanning the 1q32-1q41 region. These included D1S70 and D1S81, which are believed to flank USH2. Genotypic results and subsequent linkage analysis indicated non-linkage of this family to these markers. The A test analysis for heterogeneity with this family and 32 other Usher type II families was statistically significant at p < 0.05. Further clinical evaluation of this family was done in light of the linkage results to determine if any phenotypic characteristics would allow for clinical identification of the unlinked type. No clear phenotypic differences were observed; however, this unlinked family may represent a previously unreported subtype of Usher type II characterised by a milder form of retinitis pigmentosa and mild vestibular abnormalities. Heterogeneity of Usher syndrome type II complicates efforts to isolate and clone Usher syndrome genes using linkage analysis and limits the use of DNA markers in early detection of Usher type II.

Adolescent↗
PubMed1992

Localization of the gene for branchiootorenal syndrome to chromosome 8q.

Branchiootorenal syndrome is an autosomal dominant disorder that affects an estimated 2% of profoundly deaf children. In addition to hearing impairment, it is characterized by a lop-ear deformity, preauricular pits, branchial cleft sinus tracts, and renal anomalies. The pathogenesis of the disease remains unknown; however, the defective gene has been localized to chromosome 8q by family linkage studies.

Abnormalities, Multiple↗
PubMed1992

Linkage of Usher syndrome type I gene (USH1B) to the long arm of chromosome 11.

Usher syndrome is the most commonly recognized cause of combined visual and hearing loss in technologically developed countries. There are several different types and all are inherited in an autosomal recessive manner. There may be as many as five different genes responsible for at least two closely related phenotypes. The nature of the gene defects is unknown, and positional cloning strategies are being employed to identify the genes. This is a report of the localization of one gene for Usher syndrome type I to chromosome 11q, probably distal to marker D11S527. Another USH1 gene had been previously localized to chromosome 14q, and this second localization establishes the existence of a new and independent locus for Usher syndrome.

Base Sequence↗
PubMed1992

Localization of two genes for Usher syndrome type I to chromosome 11.

The Usher syndromes (USH) are autosomal recessive diseases characterized by congenital sensorineural hearing loss and progressive pigmentary retinopathy. While relatively rare in the general population, collectively they account for approximately 6% of the congenitally deaf population. Usher syndrome type II (USH2) has been mapped to chromosome 1q (W. J. Kimberling, M. D. Weston, C. Möller, et al., 1990, Genomics 7: 245-249; R. A. Lewis, B. Otterud, D. Stauffer, et al., 1990, Genomics 7: 250-256), and one form of Usher syndrome type I (USH1) has been mapped to chromosome 14q (J. Kaplan, S. Gerber, D. Bonneau, J. Rozet, M. Briord, J. Dufier, A. Munnich, and J. Frezal, 1990. Cytogenet. Cell Genet. 58: 1988). These loci have been excluded as regions of USH genes in our data set, which is composed of 8 French-Acadian USH1 families and 11 British USH1 families. Both of these sets of families show linkage to loci on chromosome 11. Linkage analysis demonstrates locus heterogeneity between these sets of families, with the French-Acadian families showing linkage to D11S419 (Z = 4.20, theta = 0) and the British families showing linkage to D11S527 (Z = 6.03, theta = 0). Genetic heterogeneity of the data set was confirmed using HOMOG and the M test (log likelihood ratio > 10(5)). These results confirm the presence of two distinct USH1 loci on chromosome 11.

Chromosome Mapping↗