Genomic mapping is proceeding at such a rapid pace that any printed version of the anatomy of the human genome is immediately obsolete. Although most of the scientific advances underlying the current explosion in genomic mapping have taken place in the past decade, technologic and methodologic breakthroughs since the 1950s have contributed to the mapping revolution.

Chromosome Mapping↗

PubMed1991

Review of Dr. Parkash's report.

Explore the source record for details and available documents.

Abnormalities, Multiple↗

PubMed1991

The defect in Marfan syndrome.

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Chromosomes, Human, Pair 15↗

PubMed1991

Composite graft repair of Marfan aneurysm of the ascending aorta: results in 100 patients.

One hundred consecutive patients with the Marfan syndrome underwent composite graft repair of an ascending aortic aneurysm between September 1976 and June 1989. Twenty-two patients had ascending aortic dissection at the time of composite graft repair; 18 patients also had a mitral valve procedure. There were no hospital deaths among 92 patients undergoing elective repair. One of 8 patients undergoing emergency repair of a ruptured aneurysm died in the operating room. The overall hospital mortality rate was 1%. There have been ten late deaths among the 99 hospital survivors (10.1%). Five deaths occurred among the first 11 patients in this series and five occurred among the last 88 patients (5.7%). Three late deaths resulted from composite graft endocarditis; 3 other patients with endocarditis are alive after aortic root replacement with cryopreserved homografts. Late coronary dehiscence caused death in 1 patient and was successfully repaired in a second. Actuarial survival for the 100 patients was 92.6% at 5 years and 75.8% at 10 years. Currently, composite graft repair of Marfan aneurysms of the ascending aorta can be performed with low hospital and late mortality. Marfan aneurysms with a diameter of 6 cm or greater should be repaired with the Bentall composite graft procedure, even if the patient is asymptomatic.

Adolescent↗

PubMed1991

Evidence for genetic heterogeneity in malignant hyperthermia susceptibility.

Malignant hyperthermia susceptibility (MHS) is a clinically heterogeneous pharmacogenetic disorder characterized by accelerated metabolism, hyperthermia, and frequently muscle rigidity. MHS is elicited by all commonly used potent inhalation anesthetics and depolarizing neuromuscular blockers and remains an important cause of death due to anesthesia. Recent linkage studies suggest a single genetic locus for this disorder on chromosome 19q13.1. The results of our linkage analyses exclude several loci on 19q13.1 as a site for the gene(s) that produces the MHS phenotype in three unrelated families and clearly establish genetic heterogeneity in this disorder. These results are consistent with the hypothesis that the genetic defect that alters thermoregulation may vary in MHS and that clinical variability in the expression of MHS may be explained by genetic heterogeneity.

Chromosomes, Human, Pair 19↗

PubMed1991

Current trends in mapping human genes.

The human is estimated to have at least 50,000 expressed genes (gene loci). Some information is available concerning about 5000 of these gene loci and about 1900 have been mapped, i.e., assigned to specific chromosomes (and in most instances particular chromosome regions). Progress has been achieved by a combination of physical mapping (e.g., study of somatic cell hybrids and chromosomal in situ hybridization) and genetic mapping (e.g., genetic linkage studies). New methods for both physical and genetic mapping are expanding the armamentarium. The usefulness of the mapping information is already evident; the spin-off from the Human Genome Project (HGP) begins immediately. The complete nucleotide sequence is the ultimate map of the human genome. Sequencing, although already under way for limited segments of the genome, will await further progress in gene mapping, and in particular creation of contig maps for each chromosome. Meanwhile the technology of sequencing and sequence information handling will be developed. It is argued that the HGP is a new form of coordinated, interdisciplinary science; that its primary objective must be seen as the creation of a tool for biomedical research--a source book that will be the basis of study of variation and function for a long time; that the impact on scientist training will be salutary by relieving graduate students of useless drudgery and by training scientists competent in both molecular genetics and computational science; and that the funding of the HGP will have an insignificant negative effect on science funding generally, and indeed may have a beneficial effect through economy of scale and a focusing of attention on the excitement of biology and medical science.

Chromosome Mapping↗

PubMed1991