Medical expert of the article
New publications
Lejeune syndrome (chromosome 5 short arm deletion syndrome): causes, symptoms, diagnosis, treatment
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If you feel that any of our content is inaccurate, out-of-date, or otherwise questionable, please select it and press Ctrl + Enter.
Lejeune syndrome has the following synonyms: deletion syndrome of the short arm of chromosome 5, 5p- syndrome, "cri du kitten" syndrome. The population frequency is unknown. No more than 1% of patients with profound mental retardation have a 5p- deletion.
[ What causes Lejeune syndrome?
A simple deletion of the short arm of chromosome 5 occurs during gametogenesis and is present in all cells examined, although mosaicism is occasionally detected. Sometimes the deletion occurs during the formation of the ring chromosome 5 or occurs de novo as a result of an unbalanced translocation. In 10-15% of cases, a 5p- deletion is found in a child from a parent who is a carrier of a reciprocal translocation.
Symptoms of Lejeune syndrome
- Delayed physical and psychomotor development.
- Microcephaly.
- Hypertelorism.
- Mongoloid eye shape and microgenia.
- Severe respiratory problems from birth.
- Difficulties in feeding during the newborn period.
- Congenital heart defects (15-30%, most often patent ductus arteriosus).
- Inguinal hernias (25-30%).
How to recognize Lejeune syndrome?
The diagnosis of Lejeune syndrome is based on clinical signs and the characteristic "kitten cry". Laboratory diagnostics of Lejeune syndrome is based on cytogenetic testing, which verifies the deletion of the short arm of chromosome 5.
Treatment of Lejeune syndrome
Lejeune syndrome is treated symptomatically. Genetic counseling is indicated.
What is the prognosis for Lejeune syndrome?
Lejeune syndrome has a favorable prognosis for life in the absence of severe congenital heart defects. Mental retardation of varying severity.
Использованная литература