Distal 3p deletion syndrome:: Detailed molecular cytogenetic and clinical characterization of three small distal deletions and review

The distal 3p deleton syndrome is characterized by developmental delay, low birth weight and growth retardation micro- and brachycephaly, ptosis, long philtrum, micrognathia, and low set ears. We have used FISH and BACs in order to map three 3p deletons in detail at the molecular level. The deletions were 10.2-11 Mb in size and encompassed 47-51 known genes, including the VHL gene. One of the deltions was intersitial with an intact 3p telomere. In nine previously published patients with 3p deletions, the size of the deltion was estimated using molecular or molecular cytogenetic tehniques. The genotype including genes of interest and the phenotype of these cases are compared and sicussed. The localization of the proximal breakpoint in one of our patients suggest that the previously identified critical region for heart defect may be narrowed down, now containing three candidate genes. We can also conclude that deletion of the gene ATP2B2 alone is not enough to cause hearing impairment which is frequently found in patients with 3p deletion. This is the thrid reported case with an intersitial deletion of distal 3p. (c) 2007 Wiley-Liss, Inc.