Search results
Results from the WOW.Com Content Network
[citation needed] An example of trisomy in humans is Down syndrome, which is a developmental disorder caused by an extra copy of chromosome 21; the disorder is therefore also called trisomy 21. [7] An example of monosomy in humans is Turner syndrome, where the individual is born with only one sex chromosome, an X. [8]
Trisomy 21 (also known as Down syndrome) results from a child having three copies of chromosome 21. [20] This chromosome duplication occurs during germ cell formation, when both copies of chromosome 21 end up in the same daughter cell in either the mother or father, and this mutant germ cell participates in fertilization of the zygote. [20]
The following is a list of genetic disorders and if known, type of mutation and for the chromosome involved. Although the parlance "disease-causing gene" is common, it is the occurrence of an abnormality in the parents that causes the impairment to develop within the child. There are over 6,000 known genetic disorders in humans.
Genetic variation can be identified at many levels. Identifying genetic variation is possible from observations of phenotypic variation in either quantitative traits (traits that vary continuously and are coded for by many genes, e.g., leg length in dogs) or discrete traits (traits that fall into discrete categories and are coded for by one or a few genes, e.g., white, pink, or red petal color ...
Some disorders are caused by a mutation on the X chromosome and have X-linked inheritance. Very few disorders are inherited on the Y chromosome or mitochondrial DNA (due to their size). [3] There are well over 6,000 known genetic disorders, [4] and new genetic disorders are constantly being described in medical literature. [5]
Erroneous SON function causes insufficient production of downstream targets, genome instability and disrupted cell cycle progression which are fundamental to the developmental defects and organ abnormalities in individuals with ZTTK syndrome. For example, FLNA haploinsufficiency observed in individuals with ZTTK syndrome is the main cause of a ...
An example pedigree chart of an autosomal dominant disorder An example pedigree chart of an autosomal recessive disorder An example pedigree chart of a sex-linked disorder (The gene is on the X chromosome.) The description of a mode of biological inheritance consists of three main categories: 1. Number of involved loci
Usually, all cells in an individual in a given species (plant or animal) show a constant number of chromosomes, which constitute what is known as the karyotype defining this species (see also List of number of chromosomes of various organisms), although some species present a very high karyotypic variability. In humans, mutations that would ...