Cri du chat syndrome is rare. It happens when genetic information on chromosome 5 is missing. One missing piece, called TERT (telomerase reverse transcriptase) is involved in control of cell growth, and may play a role in how some of the features of this syndrome develop.
Most cases are believed to occur during the development of the egg or sperm. A minority of cases result from one parent carrying a rearrangement of chromosome 5 called a translocation and passing this on to the baby.
Most cases of cri-du-chat syndrome are not inherited. The deletion occurs most often as a random event during the formation of reproductive cells (eggs or sperm) or in early fetal development. Affected people typically have no history of the disorder in their family.
About 10 percent of people with cri-du-chat syndrome inherit the chromosome abnormality from an unaffected parent. In these cases, the parent carries a chromosomal rearrangement called a balanced translocation, in which no genetic material is gained or lost. Balanced translocations usually do not cause any health problems; however, they can become unbalanced as they are passed to the next generation. Children who inherit an unbalanced translocation can have a chromosomal rearrangement with extra or missing genetic material. Individuals with cri-du-chat syndrome who inherit an unbalanced translocation are missing genetic material from the short arm of chromosome 5, which results in the intellectual disability and health problems characteristic of this disorder.
What are the causes of Cri du chat?
Cri du chat syndrome is rare. It happens when genetic information on chromosome 5 is missing. One missing piece, called {{ORGANIZATION}} (telomerase reverse transcriptase) is involved in control of cell growth, and may play a role in how some of the features of this syndrome develop.
Most cases are believed to occur during the development of the egg or sperm. A minority of cases result from one parent carrying a rearrangement of chromosome 5 called a translocation and passing this on to the baby.
Most cases of {{ORGANIZATION}} syndrome are not inherited. The deletion occurs most often as a random event during the formation of reproductive cells (eggs or sperm) or in early fetal development. Affected people typically have no history of the disorder in their family.
About 10 percent of people with {{ORGANIZATION}} syndrome inherit the chromosome abnormality from an unaffected parent. In these cases, the parent carries a chromosomal rearrangement called a balanced translocation, in which no genetic material is gained or lost. Balanced translocations usually do not cause any health problems; however, they can become unbalanced as they are passed to the next generation. Children who inherit an unbalanced translocation can have a chromosomal rearrangement with extra or missing genetic material. Individuals with {{ORGANIZATION}}chat syndrome who inherit an unbalanced translocation are missing genetic material from the short arm of chromosome 5, which results in the intellectual disability and health problems characteristic of this disorder.