Six cases of 7p deletion: Clinical, cytogenetic, and molecular studies

Abstract

To date, 32 cases of partial 7p monosomy have been described, 14 of which have been associated with craniosynostosis (CRS). There is considerable variation in the size and location of the deleted segment. However, CRS appears to be consistently associated with either a deletion or partial deletion 7p21-->7p22 or more rarely a deletion of 7p13-->7p14. Analysis of a panel of six 7p deletion cases (three with CRS) was undertaken using informative DNA probes, in order to characterize and define the extent of the deletions at the molecular level. There were five de novo deletions and one resulting from the unbalanced product of a paternal balanced insertion. The putative proximal CRS locus at 7p13-->7p14 does not appear to be allelic with Greig cephalopolysyndactyly syndrome. Three probe positions have been refined: pJ5.11 (D7S10) previously mapped to 7p14-->pter does not appear to map proximal to p15; TM102L (D7S135) does not map distal to p22; CRI-P137 (D7S65) maps distal to 7p13.

A novel de novo deletion of chromosome 7 [46,XX,del(7)(p14.2 p15.1)] in a child with feeding problems

“…This condition seems to be associated with a mild developmental delay and speech problems. As described in other studies the phenotype and severity of symptoms associated with deletions on chromosome 7 appear to be directly proportional to the number of deleted chromosomal regions (Chotai et al, 1994).…”

“…There is a significant association between 7p deletions and craniosynostosis that was not observed in our case (Aughton et al, 1991;Chotai et al, 1994;Reardon et al, 1993). The precise location and extension of the deletion required for craniosynostosis is still unknown as some cytogeneticists indicate 7p15 as the likely critical area while others consider the 7p21 region to be more important (Aughton et al, 1991;Brueton et al, 1992).…”

“…Deletions on chromosome 7 have been associated with a range of phenotypes including craniofacial malformations (frontal prominent, craniosynostosis, microcephaly, malformed ears, changes in the eyes and eyelids), congenital heart problems, distal limbs and genitalia malformations and moderate to severe retardation of psychomotor development (Chotai et al, 1994;Hinkel et al, 1988;Schwarzbraun et al, 2006). The phenotype and severity of symptoms associated with deletions on chromosome 7 are directly proportional to the size of the deleted segment (Kosaki et al, 2005).…”

Severe Developmental Delay in a Patient with 7p21.1–p14.3 Microdeletion Spanning the <i>TWIST</i> Gene and the <i>HOXA</i> Gene Cluster

“…He had an interrupted ear tragi and hyperplastic antihelices and antitragi but no prominent helical crura. He also had ptosis of the eyelids and short palpebral fissures (compatible with BPES syndrome) and the additional features of broad halluces medialy deviated which meet the clinical criteria for Robinow-Sorauf syndrome [Robinow and Sorauf, 1975;Chotai et al, 1994;Maw et al, 1996;Dollfus et al, 2001;Cox et al, 2002].…”

Detecting Copy Number Changes in Genomic DNA: MAPH and MLPA

“…Cytogenetically invisible deletions were first detected with probes derived either randomly (36), from a region known to be missing in a patient (37), or a translocation breakpoint (38,39). Prior to the cloning of the cDNA it was shown by Pulse-Field Gel Electrophoresis (PFGE) that gross deletions and duplications could be found in >50% of DMD cases (7).…”