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Recently, de novo heterozygous variants in DDX3X have been reported in about 1.5% of 2659 females with previously unexplained intellectual disability (ID). We report on the identification of DDX3X variants in two unrelated girls with clinical features of Toriello-Carey Syndrome (T-CS). In patient 1, the recurrent variant c.1703C>T; p.(P568L) was identified when reconsidering X-linked de novo heterozygous variants in exome sequencing data. In patient 2, the DDX3X variant c.1600C>G; p.(R534G) was also detected by exome sequencing. Based on these data, de novo heterozygous DDX3X variants should be considered not only in females with unexplained ID, but also in individuals with a clinical diagnosis of T-CS. [ABSTRACT FROM AUTHOR]

The article discusses the NOTCH1 receptor haploinsufficiency as the cause of Adams-Oliver syndrome (AOS) with cardiac anomalies. The study performed whole-exome sequencing for people diagnosed with AOS, and investigation led to the recognition of new heterozygous truncating NOTCH1 mutations. Results showed the role of NOTCH1 throughout a range of developmental anomalies, including cardiac defects and involved NOTCH1 haploinsufficiency.

Acromesomelic chondrodysplasias (ACDs) are characterized by disproportionate shortening of the appendicular skeleton, predominantly affecting the middle (forearms and forelegs) and distal segments (hands and feet). Here, we present two consanguineous families with missense (c.157T>C, p.(C53R)) or nonsense (c.657G>A, p.(W219*)) mutations in BMPR1B. Homozygous affected individuals show clinical and radiographic findings consistent with ACD-type Grebe. Functional analysis of the missense mutation C53R revealed that the mutated receptor was partially located at the cell membrane. In contrast to the wild-type receptor, C53R mutation hindered the activation of the receptor by its ligand GDF5, as shown by reporter gene assay. Further, overexpression of the C53R mutation in an in vitro chondrogenesis assay showed no effect on cell differentiation, indicating a loss of function. The nonsense mutation (c.657G>A, p.(W219*)) introduces a premature stop codon, which is predicted to be subject to nonsense-mediated mRNA decay, causing reduced protein translation of the mutant allele. A loss-of-function effect of both mutations causing recessive ACD-type Grebe is further supported by the mild brachydactyly or even non-penetrance of these mutations observed in the heterozygous parents. In contrast, dominant-negative BMPR1B mutations described previously are associated with autosomal-dominant brachydactyly-type A2. [ABSTRACT FROM AUTHOR]

Objectives: Till date, mutations in the genes PAX3 and MITF have been described in Waardenburg syndrome (WS), which is clinically characterised by congenital hearing loss and pigmentation anomalies. Our study intended to determine the frequency of mutations and deletions in these genes, to assess the clinical phenotype in detail and to identify rational priorities for molecular genetic diagnostics procedures. Design: Prospective analysis. Patients: 19 Caucasian patients with typical features of WS underwent stepwise investigation of PAX3 and MITF. When point mutations and small insertions/deletions were excluded by direct sequencing, copy number analysis by multiplex ligation-dependent probe amplification was performed to detect larger deletions and duplications. Clinical data and photographs were collected to facilitate genotype--phenotype analyses. Setting: All analyses were performed in a large German laboratory specialised in genetic diagnostics. Results: 15 novel and 4 previously published heterozygous mutations in PAX3 and MITF were identified. Of these, six were large deletions or duplications that were only detectable by copy number analysis. All patients with PAX3 mutations had typical phenotype of WS with dystopia canthorum (WS1), whereas patients with MITF gene mutations presented without dystopia canthorum (WS2). In addition, one patient with bilateral hearing loss and blue eyes with iris stroma dysplasia had a de novo missense mutation (p.Arg217IIe) in MITF. MITF 3-bp deletions at amino acid position 217 have previously been described in patients with Tietz syndrome (TS), a clinical entity with hearing loss and generalised hypopigmentation. Conclusions: On the basis of these findings, we conclude that sequencing and copy number analysis of both PAX3 and MITF have to be recommended in the routine molecular diagnostic setting for patients, WS1 and WS2. Furthermore, our genotype--phenotype analyses indicate that WS2 and TS correspond to a clinical spectrum that is influenced by MITF mutation type and position. [ABSTRACT FROM AUTHOR]

ABSTRACT Smith- Mc Cort dysplasia ( SMC) is a rare autosomal recessive spondylo-epi-metaphyseal dysplasia with skeletal features identical to those of Dyggve- Melchior- Clausen syndrome ( DMC) but with normal intelligence and no microcephaly. Although both syndromes were shown to result from mutations in the DYM gene, which encodes the Golgi protein DYMECLIN, a few SMC patients remained negative in DYM mutation screening. Recently, autozygosity mapping and exome sequencing in a large SMC family have allowed the identification of a missense mutation in RAB33B, another Golgi protein involved in retrograde transport of Golgi vesicles. Here, we report a novel RAB33B mutation in a second SMC case that leads to a marked reduction of the protein as shown by Western blot and immunofluorescence. These data confirm the genetic heterogeneity of SMC dysplasia and highlight the role of Golgi transport in the pathogenesis of SMC and DMC syndromes. [ABSTRACT FROM AUTHOR]

Interstitial deletions of chromosome band 10q22 are rare. We report on the characterization of three overlapping de novo 10q22 deletions by high-resolution array comparative genomic hybridization in three unrelated patients. Patient 1 had a 7.9 Mb deletion in 10q21.3–q22.2 and suffered from severe feeding problems, facial dysmorphisms and profound mental retardation. Patients 2 and 3 had nearly identical deletions of 3.2 and 3.6 Mb, the proximal breakpoints of which were located at an identical low-copy repeat. Both patients were mentally retarded; patient 3 also suffered from growth retardation and hypotonia. We also report on the results of breakpoint analysis by array painting in a mentally retarded patient with a balanced chromosome translocation 46,XY,t(10;13)(q22;p13)dn. The breakpoint in 10q22 was found to disrupt C10orf11, a brain-expressed gene in the common deleted interval of patients 1–3. This finding suggests that haploinsufficiency of C10orf11 contributes to the cognitive defects in 10q22 deletion patients. [ABSTRACT FROM AUTHOR]

Abstract: Background: A 12-year-old girl presenting with intermittent epigastric pains and diarrhea was referred to our clinic. Diagnostic workup revealed nonfunctional bilateral adrenal pheochromocytomas as well as a neuroendocrine tumor of the pancreatic head. This is the first report on the combination of a neuroendocrine pancreatic tumor with adrenal pheochromocytoma in a pediatric patient with von Hippel–Lindau (VHL) disease. Methods: von Hippel–Lindau disease was confirmed by molecular genetic analysis of peripheral blood lymphocytes, which revealed the mutation VHL c. 695 G > A. The family history showed also VHL disease in the mother who carried the same mutation. Results and Conclusion: Open laparotomy, organ-sparing enucleation of pheochromocytoma, and pylorus-preserving resection of the pancreatic head tumor were successfully performed. After an uneventful postoperative course, the child fully recovered. She was free of further manifestations of VHL disease 30 months after surgery. [Copyright &y& Elsevier]

Ulnar–mammary syndrome (UMS) is a rare autosomal-dominant disorder caused by mutations in TBX3. The condition is characterized by hypoplasia or aplasia of upper limbs on the ulnar side, mammary glands and nipples, and of apocrine glands in both sexes (MIM #181450). We report on a girl presenting with an UMS like phenotype, a dysmorphic facies, and mental retardation. Mutation analysis of TBX3 and G-banded chromosome analysis from lymphocytes were performed. We used microarray-based comparative genomic hybridization (array CGH) to investigate the patient's genomic DNA for submicroscopic aberrations. No mutation of the TBX3 gene was detected in our patient and chromosome analysis revealed a normal female karyotype (46,XX). Hybridization of a whole-genome tiling path array consisting of more than 36 000 BAC clones revealed an interstitial 1.28 Mb deletion within chromosomal band 12q24.21. The deleted region encompasses one known gene, TBX3. The deletion and haploinsufficiency of TBX3 was confirmed by fluorescence in situ hybridization using BAC clones representing the deletion on the BAC array. To our knowledge, this is the first description of TBX3 haploinsufficiency caused by a genomic deletion in a patient with UMS. We suggest that the UMS phenotype in conjunction with the characteristic facial changes and mental retardation observed in our patient is owing to the deletion of TBX3 and the involvement of neighbouring genes.European Journal of Human Genetics (2006) 14, 1274–1279. doi:10.1038/sj.ejhg.5201696; published online 9 August 2006 [ABSTRACT FROM AUTHOR]

Recently, deletions encompassing the nuclear receptor binding SET-Domain 1 (NSD1) gene have been described as the major cause of Japanese patients with the Sotos syndrome, whereas point mutations have been identified in the majority of European Sotos syndrome patients. In order to investigate a possible phenotype-genotype correlation and to further define the predictive value of NSD1 mutations, we performed mutational analysis of the NSD1 gene in 20 patients and one familial case with Sotos syndrome, five patients with Weaver syndrome, six patients with unclassified overgrowth/mental retardation, and six patients with macrocephaly/mental retardation. We were able to identify mutations within the NSD1 gene in 18 patients and the familial case with Sotos syndrome (90%). The mutations (six nonsense, eight frame shifts, three splice site, one missense, one in-frame deletion) are expected to result in an impairment of NSD1 function. The best correlation between clinical assessment and molecular results was obtained for the Sotos facial gestalt in conjunction with overgrowth, macrocephaly, and developmental delay. In contrast to the high mutation detection rate in Sotos syndrome, none of the patients with Weaver syndrome, unclassified overgrowth/mental retardation and macrocephaly/mental retardation, harbored NSD1 mutations. We tested for large deletions by FISH analysis but were not able to identify any deletion cases. The results indicate that the great majority of patients with Sotos syndrome are caused by mutations in NSD1. Deletions covering the NSD1 locus were not found in the patients analyzed here.European Journal of Human Genetics (2003) 11, 858-865. doi:10.1038/sj.ejhg.5201050 [ABSTRACT FROM AUTHOR]

The article presents a response by Sven Armbrust, Rolf Hoffmann, Frank Jochum, Luitgard M. Neumann, and Christoph Fusch to a letter to the editor about their article "Defective Prelamin A Processing Resulting From LMNA or ZMPSTE24 Mutations as the Cause of Restrictive Dermopathy".

Abstract: We report on a patient carrying a de novo interstitial deletion of chromosomal region 6q23.2–24.1. Interstitial deletions of 6q are rarely reported in the literature. Indeed, only four patients with interstitial deletions overlapping partially with the deleted region in our patient are described in the literature. The aberration was detected by GTG-banding. The size of the deletion was further refined by array-CGH and subsequently fine mapped by quantitative real-time PCR. The exact size of the deletion and the sequence composition of the breakpoints were determined by breakpoint spanning PCR and subsequent sequencing. The patient presented with microcephaly, short stature, patent ductus arteriosus, sensorineural hearing loss, mental retardation, reduced speech development, and abnormal behaviour. The deletion disrupts the gene EYA4. Mutations within this gene are associated with postlingual sensorineural hearing loss. The sequencing of the breakpoint indicated non homologous end joining as the most likely mechanism leading to the rearrangement. [Copyright &y& Elsevier]