Search results
Results from the WOW.Com Content Network
Turner syndrome (TS), commonly known as 45,X, or 45,XO, [note 1] is a chromosomal disorder in which cells have only one X chromosome or are partially missing an X chromosome (sex chromosome monosomy) leading to the complete or partial deletion of the pseudoautosomal regions (PAR1, PAR2) in the affected X chromosome. [2] [6] [7] Most people have ...
P – Point mutation, or any insertion/deletion entirely inside one gene; D – Deletion of a gene or genes; Dup - Duplication of a gene or genes; C – Whole chromosome extra, missing, or both (see chromosome abnormality) T – Trinucleotide repeat disorders: gene is extended in length
Monosomy, with the presence of only one chromosome (instead of the typical two in humans) from a pair, which affects chromosome 14. Fetuses with monosomy 14 are not viable. [ 1 ] Only mosaic cases exist and these usually present with severe symptoms such as intellectual disability , ocular colobomata , microcephaly , and seizures .
Human conditions due to monosomy: Turner syndrome – Females with Turner syndrome typically have one X chromosome instead of the usual two X chromosomes. Turner syndrome is the only full monosomy that is seen in humans — all other cases of full monosomy are lethal and the individual will not survive development.
XX male syndrome, also known as de la Chapelle syndrome, is a rare intersex condition in which an individual with a 46,XX karyotype develops a male phenotype. [2] Synonyms for XX male syndrome include 46,XX testicular difference of sex development (or 46,XX DSD) [3] [4] [5] [6]
A graphical representation of the typical human karyotype The human mitochondrial DNA. Human genetic variation is the genetic differences in and among populations.There may be multiple variants of any given gene in the human population (), a situation called polymorphism.
A karyotype of an individual with trisomy 21, showing three copies of chromosome 21. An abnormal number of chromosomes is known as aneuploidy, and occurs when an individual is either missing a chromosome from a pair (resulting in monosomy) or has more than two chromosomes of a pair (trisomy, tetrasomy, etc.).
Jérôme Jean Louis Marie Lejeune (French pronunciation: [ʒeʁom ʒɑ̃ lwi maʁi ləʒœn]; 13 June 1926 – 3 April 1994) was a French pediatrician and geneticist, best known for his work on the link of diseases to chromosome abnormalities, most especially the link between Down Syndrome and trisomy-21 and cri du chat syndrome, amongst several others, and for his subsequent strong opposition ...