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Smith-Magenis syndrome (SMS) is caused by an interstitial microdeletion of chromosome 17p11.2. A few patients with the typical SMS phenotype have RAI1 gene mutations. The syndrome is characterized by minor craniofacial anomalies, short stature, sleep disturbances, behavioural and neurocognitive abnormalities, as well as variable multisystemic manifestations. Periventricular nodular heterotopia (PNH) is a genetically heterogeneous neuronal migration disorder characterized by subependymal heterotopic nodules, and is variably associated with other brain malformations, epileptic seizures and intellectual disability. Here we report on two patients harboring deletions of the 17p11.2 region in whom the SMS typical phenotype was associated with bilateral PNH. Our observations expand the spectrum of chromosomal rearrangements associated with PNH and indicate that abnormal neuronal migration may contribute to the neurocognitive phenotype of SMS. © 2014 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Noonan-like syndrome with loose anagen hair (NS/LAH; OMIM 607721) is a developmental disorder clinically related to Noonan syndrome (NS) and characterized by facial dysmorphisms, postnatal growth retardation, cardiac anomalies (in particular dysplasia of the mitral valve and septal defects), variable neurocognitive impairment, and florid ectodermal features. A distinctive trait of NS/LAH is its association with easily pluckable, slow growing, sparse, and thin hair. This rare condition is due to the invariant c.4A > G missense (p.Ser2Gly) change in SHOC2, which encodes a regulatory protein that participate in RAS signaling. Here we report two patients with molecularly confirmed NS/LAH, with extremely different phenotypic expression, in particular concerning the severity of the cardiac phenotype and neurocognitive profile. While the first available clinical records outlined a relatively homogeneous phenotype in NS/LAH, the present data emphasize that the phenotype spectrum associated with this invariant mutation is wider than previously recognized. © 2014 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Bannayan-Riley-Ruvalcaba syndrome (BRRs) is an overgrowth disorder characterized by macrocephaly, pigmented maculae of the glans penis, and benign mesodermal hamartomas (primarily subcutaneous and visceral lipomas, multiple hemangiomas, and intestinal polyps). Dysmorphic features as well as delayed neuropsychomotor development can also be present. These patients have also a higher risk of developing tumors, as the gene involved in BRRs is phosphatase and tensin homologue (PTENj, and up to 30% of the patients have thyroid involvement consistent with multinodular goiter, thyroid adenoma, differentiated non-medullary thyroid cancer, or Hashimoto's thyroiditis. Here, we report two cases of BRRs at opposite ends of its phenotypic spectrum: clinical manifestations of the first patient were more severe, while the second one showed only few signs and had no family history of the disease. Both cases developed thyroid disorders detected by thyroid ultrasound screening. We believe that it is important for clinicians, specifically pediatric endocrinologists, to know that this syndrome can appear in very subtle ways and also to be aware that thyroid nodules and intestinal polyps seem to be its most frequently encountered features. [ABSTRACT FROM AUTHOR]

ABSTRACT Although Beckwith-Wiedemann syndrome (BWS, OMIM #130650) is the most common genetic overgrowth disorder, data on its epidemiology are scanty and the estimates of its occurrence show wide variability. The aim of this study is to assess its prevalence in Piedmont Region (Italy). We included in the study all patients diagnosed with BWS born in Piedmont from 1997 to 2009 through a search in the Italian Registry for Rare Diseases. This source was further validated with data from the network of Regional Clinical Genetics services and surveys in extra-regional Clinical Genetics centres, laboratories and the Italian BWS patients association. All cases were further ascertained through physical exam, medical history and specific molecular tests. The search identified 46 clear-cut cases of BWS born across the 13-year period, providing a prevalence of 1:10 340 live births (95% confidence interval 1:7,752-13,698 live births). Among the 41 patients who underwent molecular tests, 70.7% were positive, showing hypomethylation of the IC2 imprinting center (29.3%), paternal chromosome 11 uniparental disomy (pUPD11, 24.4%), IC1 hypermethylation (14.6%), CDKN1c mutation (2.4%), whereas 29.3% had negative molecular tests. The study provides an approximate BWS prevalence of 1:10,000 live birth, the highest reported to date. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

The formation of ectopic calcifications in soft tissues can occur either sporadically or as a genetically determined condition, and is seen only infrequently. We report on a girl in whom widespread, rapidly progressive ectopic calcifications were detected shortly after birth. Calcifications became present around all joints, tendons and ligaments, but did not involve internal organs and skin, and eventually caused almost complete immobility of the child at 2 years. There were no other health problems and cognitive development was normal. We compare the manifestations in the child to the characteristics of known entities causing ectopic calcifications and conclude the child differs to each. Laboratory evaluation failed to identify autoimmune phenomena as well as calcium metabolism or other biochemical abnormalities; molecular studies did not identify occurrence of mutations in disease genes known to be involved in ectopic calcifications. We conclude the manifestations in the child represent an unreported entity of hitherto unknown etiology. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Noonan syndrome (NS) is among the most common nonchromosomal disorders affecting development and growth. NS is genetically heterogeneous, being caused by germline mutations affecting various genes implicated in the RAS signaling network. This network transduces extracellular signals into intracellular biochemical and transcriptional responses controlling cell proliferation, differentiation, metabolism, and senescence. To explore the transcriptional consequences of NS-causing mutations, we performed global mRNA expression profiling on peripheral blood mononuclear cells obtained from 23 NS patients carrying heterozygous mutations in PTPN11 or SOS1. Gene expression profiling was also resolved in five subjects with Noonan-like syndrome with loose anagen hair (NS/LAH), a condition clinically related to NS and caused by an invariant mutation in SHOC2. Robust transcriptional signatures were found to specifically discriminate each of the three mutation groups from 21 age- and sex-matched controls. Despite the only partial overlap in terms of gene composition, the three signatures showed a notable concordance in terms of biological processes and regulatory circuits affected. These data establish expression profiling of peripheral blood mononuclear cells as a powerful tool to appreciate differential perturbations driven by germline mutations of transducers involved in RAS signaling and to dissect molecular mechanisms underlying NS and other RASopathies. Hum Mutat 33:703-709, 2012. © 2012 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Beckwith-Wiedemann syndrome is an overgrowth disorder characterized by neonatal macrosomia, abdominal wall defects, macroglossia, renal anomalies, organomegaly, hypoglycemia, and cancer predisposition. Hepatoblastoma is the second most frequent tumor and periodic serum alpha-fetoprotein (αFP) dosage is the cornerstone of the tumor surveillance for its early detection. In this report, we describe the outstanding case of a Beckwith-Wiedemann syndrome (BWS) newborn with severe phenotype and paternal chromosome 11 uniparental disomy (UPD11) associated with a high tumor risk. Based on the clinical picture and previous reports, a close monitoring of αFP was commenced. The marker was normal immediately after birth, but rapidly raised in 20 days, leading to the diagnosis of an extremely aggressive hepatoblastoma. The latter was successfully treated with pre-surgical reductive chemotherapy, gross total mass resection, and subsequent chemotherapy. Based on this observation, the tumor surveillance routinely suggested every 3 months should be more intense and with closer time intervals in newborns with severe BWS phenotype. We suggest monitoring neonatal αFP every 20 days in such cases. [ABSTRACT FROM AUTHOR]

Congenital portosystemic shunts (PSS) are rare vascular anomalies with different gross anatomy. Persistent patent ductus venosus (PDV) represents an uncommon cause of intrahepatic PSS. The diagnosis of this condition may not be obvious because of its wide spectrum of clinical manifestations, ranging from asymptomatic to life-threatening disease. We report the case of three boys with neuropsychological symptoms associated with mild fasting hyperammonemia. An oral protein load allowed the detection of a detoxication defect due to PSS related to PDV. This simple procedure can be worthwhile of attention in patients with mental retardation, behavior disturbances, and learning difficulties after exclusion of common causes of inherited hyperammonemia, namely, urea cycle disorders, organic acidemias, and fatty acid oxidation defects. [ABSTRACT FROM AUTHOR]

Background: Orofacial clefts are common congenital malformations usually characterized by a multifactorial etiology. These heterogeneous defects comprise cleft lip (CL), CL with cleft palate (CL/P), and cleft palate, sometimes observed in recognizable syndromes, with mendelian, chromosomal, or environmental pathogenesis. The Van der Woude syndrome is a mendelian CL/P, accounting for about 2% of all cases and caused by mutations in the interferon regulatory factor 6 (IRF6) gene, located on 1q32.2 chromosome.Objective: Here, we describe a familial case with a novel IRF6 mutation segregating in the maternal line, displaying a highly intrafamilial variable clinical expression.Conclusion: This report emphasizes the role of the clinician in recognizing the clinical variability and the genetic heterogeneity of CL/P. [ABSTRACT FROM AUTHOR]

Williams–Beuren syndrome (WBS; OMIM no. 194050) is a multisystemic neurodevelopmental disorder caused by a hemizygous deletion of 1.55 Mb on chromosome 7q11.23 spanning 28 genes. Haploinsufficiency of the ELN gene was shown to be responsible for supravalvular aortic stenosis and generalized arteriopathy, whereas LIMK1, CLIP2, GTF2IRD1 and GTF2I genes were suggested to be linked to the specific cognitive profile and craniofacial features. These insights for genotype–phenotype correlations came from the molecular and clinical analysis of patients with atypical deletions and mice models. Here we report a patient showing mild WBS physical phenotype and normal IQ, who carries a shorter 1 Mb atypical deletion. This rearrangement does not include the GTF2IRD1 and GTF2I genes and only partially the BAZ1B gene. Our results are consistent with the hypothesis that hemizygosity of the GTF2IRD1 and GTF2I genes might be involved in the facial dysmorphisms and in the specific motor and cognitive deficits observed in WBS patients. [ABSTRACT FROM AUTHOR]

The RAF1:p.Ser257Leu variant is associated with severe Noonan syndrome (NS), progressive hypertrophic cardiomyopathy (HCM), and pulmonary hypertension. Trametinib, a MEK-inhibitor approved for treatment of RAS/MAPK-mutated cancers, is an emerging treatment option for HCM in NS. We report a patient with NS and HCM, treated with Trametinib and documented by global RNA sequencing before and during treatment to define transcriptional effects of MEK-inhibition. A preterm infant with HCM carrying the RAF1:p.Ser257Leu variant, rapidly developed severe congestive heart failure (CHF) unresponsive to standard treatments. Trametinib was introduced (0.022 mg/kg/day) with prompt clinical improvement and subsequent amelioration of HCM at ultrasound. The appearance of pulmonary artery aneurysm and pulmonary hypertension contributed to a rapid worsening after ventriculoperitoneal shunt device placement for posthemorrhagic hydrocephalus: she deceased for untreatable CHF at 3 months of age. Autopsy showed severe obstructive HCM, pulmonary artery dilation, disarrayed pulmonary vascular anatomy consistent with pulmonary capillary hemangiomatosis. Transcriptome across treatment, highlighted robust transcriptional changes induced by MEK-inhibition. Our findings highlight a previously unappreciated connection between pulmonary vascular disease and the severe outcome already reported in patients with RAF1-associated NS. While MEK-inhibition appears a promising therapeutic option for HCM in RASopathies, it appears insufficient to revert pulmonary hypertension. [ABSTRACT FROM AUTHOR]