Chat du sex
Older pregnant women have a higher risk of passing on chromosomal genetic disorders.
Most affected infants also display some degree of psychomotor and intellectual disability.However, it is possible that a parent with the chromosomal deletion can pass on the broken chromosome to offspring.Researchers believe that the loss of one particular gene, called CTNND2, causes the cognitive disabilities associated with the disease.Distinctive facial features may include an abnormally round or plump (moon) face, a broad nasal bridge, widely spaced eyes (hypertelorism), crossed eyes (strabismus), downwardly slanting eyelid folds (palpebral fissures), vertical skin folds that may cover the eyes’ inner corners (epicanthal folds), low-set ears, and an abnormally small jaw (micrognathia).Improper alignment of the upper and lower teeth (malocclusion) may also occur.Additional symptoms affecting different organ systems of the body can also occur.
Most cases are thought arise from spontaneous (de novo) genetic errors very early in embryonic development.
Moderate to severe intellectual disability is present in most cases.
Speech development is especially delayed in children with cri du chat syndrome.
Additional facial features include an abnormally small distance from the upper lip to the nose (short philtrum), incomplete closure of the roof of the mouth (cleft palate), an abnormal groove or gap in the upper lip (cleft lip), and abnormal fullness of the lower lip.
In addition, the fleshy mass (uvula) that hangs in the back of the throat may be spilt (bifid uvula).
During pregnancy chromosomal abnormalities can cause the death of an embryo or fetus.