156 - Chromosome 5p Deletion Syndrome (Cri du Chat Syndrome)

Abstract

Monosomy for the distal portion of the short arm of chromosome 5 causes 5p deletion syndrome, which is also known by the currently less favored term “cri du chat” syndrome, from the French description of the monotonous high-pitched “cat-like” cry of affected infants. Initially described in 1963 by Lejeune et al., this syndrome is readily detectable by karyotype or with molecular cytogenetic methods, such as chromosomal microarray analysis (CMA). The prenatal diagnosis of this rare deletion syndrome is relatively uncommon. However, the recent introduction of noninvasive prenatal screening for microdeletion syndromes using cell-free fetal DNA (cffDNA) in maternal plasma has widened the prenatal ascertainment of 5p deletion syndrome to screening for potentially affected fetuses in low-risk pregnancies. Thus practitioners should be familiar with the clinical presentation and prognosis of 5p deletion syndrome, including features that can be seen by prenatal imaging and those that are not prenatally detectable, as well as with the implications for perinatal management and counseling when a 5p deletion is diagnosed prenatally.