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Chromosomal rearrangements in the short arm of chromosome 4 can result in 2 different clinical entities: Wolf-Hirschhorn syndrome (WHS), characterized by severe growth delay, mental retardation, microcephaly, 'Greek helmet' facies, and closure defects, or partial 4p trisomy, associated with multiple congenital anomalies, mental retardation, and facial dysmorphisms. We present clinical and laboratory findings in a patient who showed a small duplication in 4p16.3 associated with a subtle terminal deletion in the same chromosomal region. GTG-banding analyses, multiplex ligation-dependent probe amplification analyses, and studies by array-based comparative genomic hybridization were performed. The results of the analyses revealed a de novo 1.3 Mb deletion of the terminal 4p and a 1.1 Mb duplication in our patient, encompassing the WHS critical region. Interestingly, this unusual duplication/deletion rearrangement results in an intermediate phenotype that shares characteristics of the WHS and the 4p trisomy syndrome. The use of novel technologies in the genetic diagnosis leads to the description of new clinical syndromes; there is a growing list of microduplication syndromes. Therefore, we propose that overexpression of candidate genes in WHS (WHSC1, WHSC2 and LETM1) due to a duplication causes a clinical entity different to both the WHS and 4p trisomy syndrome., ((c) 2009 S. Karger AG, Basel.)

Submicroscopic deletions of 1q44-qter cause severe mental retardation, profound growth retardation, microcephaly and corpus callosum hypo/agenesis in most patients. At least 3 intervals in 1q44 have been described as critical regions containing genes leading to corpus callosum abnormalities. In this report we describe a patient with a de novo small interstitial 1q44 deletion of 1,152 kb detected with 44K oligonucleotide array-CGH (44K Agilent Technologies) and a mild phenotype lacking corpus callosum abnormalities. The first deleted oligonucleotide was located at 242.638 Mb (within the ADSS gene), and the last deleted oligonucleotide at 243.791 Mb (within the KIF26B gene). The clinical and molecular findings of the patient here reported remain consistent with a role for the AKT3 or ZNF238 genes in corpus callosum development., (2010 S. Karger AG, Basel.)

Background and Objective: Subtelomeric chromosome imbalances are increasingly known as a cause for mental retardation. New phenotypes associated with specific rearrangements are also being delineated, such as 9q microdeletion syndrome. Here we define the major phenotypic features and the parental origin of 9q deletion., Patients and Method: We present 2 children with a phenotype that is characterized by mental retardation, distinctive facial features and congenital anomalies. Both patients showed a chromosome 9q subtelomeric deletion detected by MLPA (multiplex ligation-dependent probe amplification), and confirmed by FISH (fluorescent in situ hybridization). In order to delimit the size and the parental origin of 9q deletion, we performed microsatellite segregation analyses., Results: We identified 2 patients with a de novo terminal deletion of the chromosome region 9q34. The deleted region spanned less than 0.8 and 1.5 Mb, respectively, affecting in both cases the paternal chromosome., Conclusions: 9q34 deletion syndrome appears as a clinically recognizable phenotype characterised by moderate-severe mental retardation, hypotonia, flat face with hyperthelorism, synophrys, anteverted nares, carp-shaped mouth with protruding tongue and conotruncal heart defects. Most de novo deletions arise in the chromosomes of paternal origin.