Genetic diseases in humans


Extremely short finger was the first property that was proven to have Mendelian inheritance in man (1903). Some other examples of autosomal dominant characteristics are given in the table, including the Huntington's chorea (hereditary Vitus's dance, Setesdal Rykkja, first described by the district Lund). The first diseases recognized to have recessive inheritance in man, was the type of congenital metabolic disorders, first described in 1902 and 1908. Otto Lous Mohr published in the period 1920-1944 Mendelian inheritance of a variety of conditions, including evidence for recessive inheritance at Foaling disease.

Asbjorn Foaling described in 1934 the disease phenylketonuria (PKU or Foaling disease). The disease is caused abolished function of a liver enzyme that normally transferred the amino acid phenylalanine to tyrosine. In PKU, patients do not happen, and it is formed rather than metabolic products that lead to mental disability and characteristic movement disorders. Today revealed PKU blood samples of newborns, and by a special diet could be retarded avoided. Arve plant was in the 1980s were cloned by the classical method? First determined amino acid sequence in enzyme protein, as stock is a small piece of DNA from the genetic code, then we use this DNA piece (the probe) to fish out the correct DNA snippet from nuclear DNA and map the rest of the gene. A portion of the gene was "in situ hybridized" on chromosome preparations and its localization on chromosome 12 identified. In 1999 found 33 unusual mutations in the Foaling (PAH) gene, and the geographical distribution is different for most people.
human genetic diseases

Normal albinism is not only one but two independent recessive diseases. The one is the lack of normal tyrosinase activity that makes the pigment melanin is not formed at the other the lack of a P-protein. The two types can be distinguished by tyrosinase test the hair from albino individuals, or by detection of the mutation in their gene. This is important for genetic counseling.

Among examples of hereditary diseases first described, are also the dominant Müller-Harbitz disease (1930) (hyper cholesterol) and recessive conditions Norum and Gjone Disease (1967), Refsum's disease (1946), Seip Disease (1959) , Aagenæs' disease (1968), and a variety of metabolic diseases discovered since the 1970s by L. Eldjarn, E. Jellum, EA Kvittingen and O. Stokke. For several of this is the gene cloned and the mutations found in the same order: LCLR (chromosome 19), LCAT (chromosome 16), PAHX (chromosome 10 and others), BSCL2 (chromosome 11, codes for the protein seipin for MARTIN SEIP ). By Aagenæs' disease (chromosome 15) and by ichthyosis-prematurity syndrome (chromosome 9, see the map) is chromosomal localization, but not the genes found (per 2004).

The most frequent of the serious recessive diseases among northern Europeans are cystic fibrosis. The gene for this was found at position mapping: In 1985, they found genetic markers that followed the disease inheritance (genetic link), afterwards mapped the Mon a linked DNA marker to chromosome 7, then followed an intense search along the chromosome up to date new gene was proven to be the right (1989). When the gene was cloned so, one could sequence the DNA and find the mutations. It is now found over 300 different mutations in the gene; one of thirty plants carries and 66% of those carrying a particular mutation. While every 2000. Birth or more with us gives a homozygous (ill) children, the disease is almost unknown in the Finnish population.

Already in 1917 wrote a doctor (Magnus) that a healthy Mothers-related fish Ehud (ichthyosis) with several men had caused X-linked inheritance. This and other observation were overlooked until sex-linked ichthyosis was "proven" and widely recognized in the l960's. An example of the dominant X-linked gene is what gives the vitamin-resistant rickets. Most of the disease and the X chromosome has recessive effects; that is, almost exclusively boys get the disease (sex-linked inheritance). Two severe hemophilia, hemophilia A and hemophilia B is caused by recessive plants in each of their location on the X chromosome. Both facilities are now cloned and known in detail, as DNA studies can be used for precise genetic counseling. Red and green color blindness are sex-linked, but the two tightly coupled genes that are so frequent (8% of men) that women sometimes have facilities on both their X chromosomes and therefore, color-blind (0.2% of women). Pediatrician Arne Nja described 1946 as the first, that some form of gargoylism was sex-linked hereditary, but it was Hunter, who later had his name attached to the disease. Furthermore, first described is Aarskog Syndrome (1970), where the gene on the X chromosome was found at position mapping in 1994.