A map of the genes on a chromosome based on linkage analysis. A linkage map does not show the physical distances between genes but rather their relative positions, as determined by how often two gene loci are inherited together. The closer two genes are (the more tightly they are linked), the more often they will be inherited together. Linkage distance is measured in centimorgans (cM).
- Map, physical
A map of the locations of identifiable landmarks on chromosomes. Physical distance is measured in base pairs. The physical map differs from the genetic map which is based purely on genetic linkage data. In the human genome, the lowest-resolution physical map is the banding patterns of the 24 different chromosomes. The highest-resolution physical map is […]
- Map-dot-fingerprint type corneal dystrophy
Cogan corneal dystrophy. It is also known (to add to the confusion) as microcystic corneal dystrophy.
- Maple syrup urine disease
A hereditary disease that is due to deficiency of an enzyme involved in amino acid metabolism, characterized by urine that smells like maple syrup. In maple syrup urine disease, the three branched-chain amino acids (leucine, isoleucine, and valine) cannot be metabolized (processed), and they build up in the blood, causing problems with brain function and […]
- Mapping, gene
The charting of the positions of genes on a DNA molecule or chromosome and the distance, in linkage units or physical units, between genes.
Wasting away, as occurs with children who have kwashiorkor. Also called cachexia, is usually a result of protein and calorie deficiency.