What is the mutation of duplication?
A type of mutation in which a portion of a genetic material or a chromosome is duplicated or replicated, resulting in multiple copies of that region. Duplication results from an unequal crossing-over between misaligned homologous chromosomes during meiosis.
What is an example of duplication mutation?
One example of a rare genetic disorder of duplication is called Pallister-Killian syndrome, where part of the #12 chromosome is duplicated.
Is 22q duplication a disability?
The features of this condition vary widely, even among members of the same family. Affected individuals may have developmental delay, intellectual disability, slow growth leading to short stature, and weak muscle tone (hypotonia). Many people with the duplication have no apparent physical or intellectual disabilities.
Is trisomy 21 a duplication?
Since the identification of trisomy 21 as the cause of DS in 1959, reports of individuals with this condition due to duplication of parts of chromosome 21 have appeared.
What is the cause of duplication?
Duplications arise from an event termed unequal crossing-over that occurs during meiosis between misaligned homologous chromosomes. The chance of it happening is a function of the degree of sharing of repetitive elements between two chromosomes.
How many types of duplication are there?
Gene duplication can occur by several mechanisms, including whole-genome duplication (WGD) and single gene duplication. Single gene duplication includes four types, tandem (TD), proximal (PD), retrotransposed (RD), DNA-transposed (DD) and dispersed duplication (DSD) (Freeling, 2009; Hahn, 2009; Wang et al., 2012b).
Which condition is caused by an XXY genotype?
Klinefelter syndrome can be caused by: One extra copy of the X chromosome in each cell (XXY), the most common cause. An extra X chromosome in some of the cells (mosaic Klinefelter syndrome), with fewer symptoms. More than one extra copy of the X chromosome, which is rare and results in a severe form.
Is 22q a form of autism?
Many children with 22q have some social difficulties, developmental delays or learning disabilities. For the majority, the symptoms are not severe or extensive enough to warrant an autism diagnosis. Individuals with 22q also share common health issues. Many have heart defects and immune problems.
Is 22q a form of Down syndrome?
22q11. 2 deletion is almost as common as Trisomy 21, also known as Down syndrome, which is a more widely recognized chromosomal disorder. Children with 22q11.
What is the difference between trisomy 21 and translocation Down syndrome?
Translocation Down syndrome refers to the type of Down syndrome that is caused by rearranged chromosome material. In this case, there are three # 21 chromosomes, just like there are in trisomy 21, but one of the 21 chromosomes is attached to another chromosome, instead of being separate.