16p11.2 duplication (16p11.2 duplication) - Chromosome 16
The 16p11.2 duplication is a chromosomal change in which a small amount of genetic material from chromosome 16 is not duplicated correctly. The duplication occurs near half of chromosome in a place known as p11.2. This duplication can have a variety of effects. The usual signs and symptoms that show people with 16p11.2 duplication include low birth weight, microcephaly, developmental delay (especially the language) and behavioral problems. However, in some people with replication they have not been described physical or behavioral abnormalities.
The developmental delay and intellectual disability can occur in people with 16p11.2 duplication. Approximately one third of affected children lag behind in the development of motor skills. The average intelligence quotient (IQ) of people affected is about 26 less than their parents without duplication points. About 80 percent of people with 16p11.2 duplication have problems with speech or language. Both expressive language skills, as the receptive language skills may be affected. One of the most common behavioral problems associated with this chromosomal change is the attention deficit hyperactivity disorder. Autism spectrum disorders are diagnosed in about one in five people with 16p11.2 duplication. Affected individuals also have a higher risk of mental health problems including schizophrenia, anxiety and depression. In addition, it is likely that affected individuals suffer from seizures.
Other possible anomalies include kidney and urinary tract malformations. However, no specific pattern of physical abnormalities characterizing the 16p11.2 duplication; Signs and symptoms related to chromosomal change vary even among affected members of the same family.
People with 16p11.2 duplication have an extra copy of a segment of genetic material on the short arm of chromosome 16 in the position p11.2. This duplication affects one of the two copies of chromosome 16 in each cell. Most often, the length of the duplicated segment is around 600,000 base pairs (600 kb). 600 kb region contains more than 25 genes, and little is known about the function of most of these genes. Work is underway to determine how the extra genetic material contributes to the characteristics of 16p11.2 duplication.
Chromosome 16 likely contains 800 to 900 genes encoding protein synthesis. These proteins play a variety of different functions in the body. The 16p11.2 duplication may involve similar symptoms to deletion 16p11.2 in some affected individuals, including autism spectrum characteristics; however, the low weight is common in people with duplication, while obesity is common in those individuals carrying a deletion 16p11.2. The 16p11.2 duplication seems to have a milder effect that deletion, with a higher proportion of individuals with this chromosomal changes that show no apparent problems. These individuals can transmit doubling their children, who may have related symptoms chromosome change. Work is underway to determine how the extra genetic material contributes to the characteristics that occur in some people with 16p11.2 duplication, and why duplication or deletion of the same chromosomal region may have some similar effects.
The 16p11.2 duplication has an autosomal dominant inheritance, which means that a duplicate copy of chromosome 16 in each cell is sufficient to express the process. Most affected individuals inherit the duplication of an affected parent. These individuals may have similar characteristics of the disease compared to their parents, or they may be more or less severely affected. However, in some cases 16p11.2 duplications are not inherited. Instead, they occur as random events during the formation of reproductive cells or early embryonic development. People with a new mirror usually have no history of signs or symptoms related to his family, but their offspring can inherit the chromosome change.
Tests in IVAMI: IVAMI performed in the study of duplication on chromosome 16, by comparative tests amplification amplification of other genes by quantitative real - time PCR (qPCR).
Samples recommended: EDTA blood collected for separation of blood leukocytes, or impregnated sample card with dried blood (IVAMI may mail the card to deposit the blood sample).