5p deletions: Current knowledge and future directions

Abstract

Disorders resulting from 5p deletions (5p–) were first recognized by Lejeune et al. in 1963 [Lejeune et al. (1963); C R Hebd Seances Acad Sci 257:3098-3102]. 5p– is caused by partial or total deletion of the short arm of chromosome 5. The most recognizable phenotype is characterized by a high-pitched cry, dysmorphic features, poor growth, and developmental delay. This report reviews 5p– disorders and their molecular basis. Hemizygosity for genes located within this region have been implicated in contributing to the phenotype. A review of the genes on 5p which may be dosage sensitive is summarized. Because of the growing knowledge of these specific genes, future directions to explore potential targeted therapies for individuals with 5p– are discussed.

Prenatal sonographic diagnosis of isolated fetal ascites in cri‐du‐chat (5p‐) syndrome: A case report

“…They represent de novo events, probably resulting from abnormal chromosome breakage during male gamete formation. Unbalanced parental translocation is responsible for the remaining 10%‐15% of cases and less than 1% are due to interstitial deletion, ring five chromosome, mosaicism, and other rare aberrations . In this case, since the parents refused to undergo genetic testing, we were unable to confirm whether this deletion was de novo , an inherited unbalanced translocation or a rare aberration.…”

“…Cri‐du‐chat syndrome (CdCS) or 5p deletion syndrome (OMIM # 123450, ORPHA:281) was first described in 1963 by Lejeune and collaborators . Although rare, it has been suggested as one of the most common contiguous gene deletion disorders, with an incidence of 1:15 000 to 1:50 000 live births . It results from a deletion of the short arm of chromosome 5, ranging from partial deletion of the critical region of 5p15.2 to the entire short arm.…”

“…Classic phenotype also includes dysmorphic features along with severe psychomotor and developmental delay. Variability seen among individuals may be attributed to differences in their genotypes . Although a number of cases of CdCS have been documented, only few reports have described antenatal US features .…”

Partial 5p Deletion and Partial 5q Duplication in a Patient with Multiple Congenital Anomalies: A Two-Step Mechanism in Chromosomal Rearrangement Mediated by Non-Allelic Homologous Recombination

“…Most of the chromosome 5p deletions are de novo occurrences, which are paternal in origin in 80-90% of cases [Nguyen et al, 2015]. The remaining cases are the result of inheritance of an unbalanced translocation [Mainardi et al, 2001;Mainardi, 2006;Nguyen et al, 2015;Zhang et al, 2016]. Patients with simultaneous 5p deletion and 5q duplication have been rarely reported, and most of them have a terminal deletion and a terminal duplication due to a recombinant chromosome originating from a parental pericentric inversion [de Perdigo et al, 1989].…”

“…The deletions can be either terminal or interstitial and vary in size ranging from extremely small, involving only band 5p15.2, to the entire short arm. Most of the chromosome 5p deletions are de novo occurrences, which are paternal in origin in 80-90% of cases [Nguyen et al, 2015]. The remaining cases are the result of inheritance of an unbalanced translocation [Mainardi et al, 2001;Mainardi, 2006;Nguyen et al, 2015;Zhang et al, 2016].…”