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MECP2 duplication syndrome (MDS) is an X-linked neurodevelopmental disorder characterized by a severe to profound intellectual disability, early onset hypotonia and diverse psycho-motor and behavioural features. To date, fewer than 200 cases have been published. We report the clinical and molecular characterization of a Spanish MDS cohort that included 19 boys and 2 girls. Clinical suspicions were confirmed by array comparative genomic hybridization and multiplex ligation-dependent probe amplification (MLPA). Using, a custom in-house MLPA assay, we performed a thorough study of the minimal duplicated region, from which we concluded a complete duplication of both MECP2 and IRAK1 was necessary for a correct MDS diagnosis, as patients with partial MECP2 duplications lacked some typical clinical traits present in other MDS patients. In addition, the duplication location may be related to phenotypic severity. This observation may provide a new approach for genotype-phenotype correlations, and thus more personalized genetic counselling. more...

Familial incontinentia pigmenti (IP) is a rare X-linked dominant disorder that affects ectodermal tissues. Over 90% of IP carrier females have a recurrent genomic deletion of exons 4-10 of the NEMO (IKBKG-IKKgamma) gene, which encodes a regulatory component of the IkB kinase complex, required to activate the NF-kB pathway. In IP, mutations in NEMO lead to the complete loss of NF-kB activation creating a susceptibility to cellular apoptosis in response to TNF-alpha. This condition is lethal for males during embryogenesis while females, who are mosaic as a result of X-inactivation, can survive. Recently, a second nonfunctional copy of the gene, DeltaNEMO, was identified, opposite in direction to NEMO in a 35.5-kb duplicated sequence tract. PCR-based detection of the NEMO deletion is diagnostic for IP disease. However, we present instances in which ex 4-10 DeltaNEMO pseudogene deletion occurs in unaffected parents of two females with clinically characteristic IP These were missed by the currently standard PCR- based method, but can be easily discriminated by a new PCR-based test reported here that permits unambiguous molecular diagnosis and proper familial genetic counseling for IP. more...

Sotos syndrome is a well-described multiple anomaly syndrome characterized by overgrowth, distinctive craniofacial appearance, and variable learning disabilities. The diagnosis of Sotos syndrome relied solely on these clinical criteria until haploinsufficiency of the NSD1 gene was identified as causative. We describe a 63-year-old woman with classic features and a pathogenic NSD1 mutation, who we believe to be the oldest reported person with Sotos syndrome. She is notable for the diagnosis of Sotos syndrome late in life, mild cognitive limitation, and chronic kidney disease attributed to fibromuscular dysplasia for which she recently received a transplant. She has basal cell and squamous cell carcinoma for which her lifetime of sun exposure and fair cutaneous phototype are viewed as risk factors. We also reviewed previous literature reports (n = 11) for adults with Sotos syndrome, and studied patients ascertained in the Spanish Overgrowth Syndrome Registry (n = 15). Analysis was limited to 21/27 (78%) total patients who had molecular confirmation of Sotos syndrome (15 with a mutation, 6 with a microdeletion). With a mean age of 26 years, the most common features were learning disabilities (90%), scoliosis (52%), eye problems (43%), psychiatric issues (30%), and brain imaging anomalies (28%). Learning disabilities were more severe in patients with a microdeletion than in those with a point mutation. From this small study with heterogeneous ascertainment we suggest modest adjustments to the general healthcare monitoring of individuals with Sotos syndrome. Although this series includes neoplasia in four cases, this should not be interpreted as incidence. Age-appropriate cancer surveillance should be maintained. © 2011 Wiley-Liss, Inc. more...

Beckwith–Wiedemann syndrome (BWS) is a phenotypically and genotypically heterogeneous overgrowth syndrome characterized by somatic overgrowth, macroglossia and abdominal wall defects. Other usual findings are hemihyperplasia, embryonal tumours, adrenocortical cytomegaly, ear anomalies, visceromegaly, renal abnormalities, neonatal hypoglycaemia, cleft palate, polydactyly and a positive family history. BWS is a complex, multigenic disorder associated, in up to 90% of patients, with alteration in the expression or function of one or more genes in the 11p15.5 imprinted gene cluster. There are several molecular anomalies associated with BWS and the large proportion of cases, about 85%, is sporadic and karyotypically normal. One of the major categories of BWS molecular alteration (10–20% of cases) is represented by mosaic paternal uniparental disomy (pUPD), namely patients with two paternally derived copies of chromosome 11p15 and no maternal contribution for that. In these patients, in addition to the effects of IGF2 overexpression, a decreased level of the maternally expressed gene CDKN1C may contribute to the BWS phenotype. In this paper, we reviewed a series of nine patients with BWS because of pUPD using several methods with the aim to evaluate the percentage of mosaicism, the methylation status at both loci, the extension of the pUPD at the short arm and the breakpoints of recombination. Fine mapping of mitotic recombination breakpoints by single-nucleotide polymorphism-array in individuals with UPD and fine estimation of epigenetic defects will provide a basis for understanding the aetiology of BWS, allowing more accurate prognostic predictions and facilitating management and surveillance of individuals with this disorder. more...

et al., Hedgehog (Hh) signaling is involved in patterning and morphogenesis of most organs in the developing mammalian embryo. Despite many advances in understanding core components of the pathway, little is known about how the activity of the Hh pathway is adjusted in organ- and tissue-specific developmental processes. Mutations in EVC or EVC2 disrupt Hh signaling in tooth and bone development. Using mouse models, we show here that Evc and Evc2 are mutually required for localizing to primary cilia and also for maintaining their normal protein levels. Consistent with Evc and Evc2 functioning as a complex, the skeletal phenotypes in either single or double homozygous mutant mice are virtually indistinguishable. Smo translocation to the cilium was normal in Evc2-deficient chondrocytes following Hh activation with the Smo-agonist SAG. However, Gli3 recruitment to cilia tips was reduced and Sufu/Gli3 dissociation was impaired. Interestingly, we found Smo to co-precipitate with Evc/Evc2, indicating that in some cells Hh signaling requires direct interaction of Smo with the Evc/Evc2 complex. Expression of a dominantly acting Evc2 mutation previously identified in Weyer's acrodental dysostosis (Evc2ο43) caused mislocalization of Evc/Evc2ο43 within the cilium and also reproduced the Gli3-related molecular defects observed in Evc2-/- chondrocytes. Moreover, Evc silencing in Sufu-/- cells attenuated the output of the Hh pathway, suggesting that Evc/Evc2 also promote Hh signaling in the absence of Sufu. Together our data reveal that the Hh pathway involves Evc/Evc2-dependent modulations that are necessary for normal endochondral bone formation. © The Author 2012. Published by Oxford University Press. All rights reserved., This work was funded by the Spanish Ministry of Science and Innovation (SAF-17901), the European Union (LSHM-CT-2007-03741) and the Ramón Areces Foundation. more...

Macrocephaly-capillary malformation (M-CM) is a genetic syndrome of unknown etiology characterized by an enlarged head circumference and patchy, reticular capillary malformation. We describe the clinical features of 13 cases, report on the genome-wide Copy Number Variation characterization of these patients, analyze the main clinical features of this syndrome and propose a modification of the current diagnostic criteria: the inclusion of both overgrowth/asymmetry and neuroimaging alterations as major criteria. more...

Retinitis pigmentosa (RP) is a group of genetically heterogeneous retinal degenerations that can be autosomal dominant (ADRP), autosomal recessive (ARRP), or X-linked. Approximately 30% of ADRP patients show point mutations or small deletions in the rhodopsin gene. However, over 50% of the RP patients are simplex cases (sporadic). Screening for mutations in the rhodopsin gene of 33 patients with simplex RP by denaturing gradient gel electrophoresis (DGGE) was carried out. One patient, with D-type (diffuse) RP and consanguineous parents, showed an altered electrophoretic pattern for the 5′ half of exon 1. Direct sequencing revealed a new mutation ATG to ACG in codon 44; this predicts a change of Met-44-Thr in rhodopsin. The position and amino acid substitution suggest that this mutation causes the RP phenotype. Implications for genetic counselling are discussed. more...