Medical expert of the article
New publications
Diagnosis of syndromes caused by structural abnormalities of chromosomes (deletion syndromes)
Last reviewed: 05.07.2025
All iLive content is medically reviewed or fact checked to ensure as much factual accuracy as possible.
We have strict sourcing guidelines and only link to reputable media sites, academic research institutions and, whenever possible, medically peer reviewed studies. Note that the numbers in parentheses ([1], [2], etc.) are clickable links to these studies.
If you feel that any of our content is inaccurate, out-of-date, or otherwise questionable, please select it and press Ctrl + Enter.
Deletion syndromes most often result from the loss of the short arms of chromosomes.
Cri-du-chat syndrome is associated with a deletion of the short arm of chromosome 5 (5p- syndrome). The typical symptom of the disease is a characteristic cry of the newborn, reminiscent of the meowing of a cat (due to an anomaly in the development of the larynx and vocal cords). This symptom appears immediately after birth, persists for several weeks, and then disappears. In most cases, the syndrome also manifests itself in multiple developmental defects and mental retardation.
4p deletion syndrome is very rare. Clinically it resembles "cri du chat" syndrome, but the characteristic cry is absent. Microcephaly, cleft palate, and profound mental retardation are characteristic.
Microdeletion syndromes of adjacent genes. Microdeletions of adjacent genes on a chromosome cause a number of very rare syndromes (Prader-Willi, Miller-Dieker, DiGeorge, etc.). Diagnosis of these syndromes has become possible due to the improvement of the method of preparing chromosome preparations. If the microdeletion cannot be detected by karyotyping, DNA probes specific to the region that has been deleted are used.
[