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Abstract Background Intellectual disability affects approximately 1 to 3% of the general population. The etiology is still poorly understood and it is estimated that one-half of the cases are due to genetic factors. Cryptic subtelomeric aberrations have been found in roughly 5 to 7% of all cases. Methods We performed a subtelomeric FISH analysis on 76 unrelated children with normal standard karyotype ascertained by developmental delay or intellectual disability, associated with congenital malformations, and/or facial dysmorphisms. Results Ten cryptic chromosomal anomalies have been identified in the whole cohort (13,16%), 8 in the group of patients characterized by developmental delay or intellectual disability associated with congenital malformations and facial dysmorphisms, 2 in patients with developmental delay or intellectual disability and facial dysmorphisms only. Conclusion We demonstrate that a careful clinical examination is a very useful tool for pre-selection of patients for genomic analysis, clearly enhancing the chromosomal anomaly detection rate. Clinical features of most of these patients are consistent with the corresponding emerging chromosome phenotypes, pointing out these new clinical syndromes associated with specific genomic imbalances.

Background: Beckwith‐Wiedemann syndrome (BWS) phenotype usually mitigates with age and data on adulthood are limited. Our study aims at reporting phenotype evolution and health issues in adulthood. Methods: 34 patients (16 males), aged 18–58 years (mean 28.5) with BWS were enrolled. Results: 26 patients were molecularly confirmed, 5 tested negative, and 3 were not tested. Final tall stature was present in 44%. Four patients developed Wilms' Tumor (2, 3, 5, and 10 years, respectively); one hepatoblastoma (22 years); one acute lymphoblastic leukemia (21 years); one adrenal adenoma and testicular Sertoli cell tumor (22 and 24 years, respectively); and three benign tumors (hepatic haemangioma, uterine myoma, and mammary fibroepithelioma). Surgery for BWS‐related features was required in 85%. Despite surgical correction several patients presented morbidity and sequelae of BWS pediatric issues: pronunciation/swallow difficulties (n = 9) due to macroglossia, painful scoliosis (n = 4) consistent with lateralized overgrowth, recurrent urolithiasis (n = 4), azoospermia (n = 4) likely consequent to cryptorchidism, severe intellectual disability (n = 2) likely related to neonatal asphyxia and diabetes mellitus (n = 1) due to subtotal pancreatectomy for intractable hyperinsulinism. Four patients (two males) had healthy children (three physiologically conceived and one through assisted reproductive technology). Conclusions: Adult health conditions in BWS are mostly consequent to pediatric issues, underlying the preventive role of follow‐up strategies in childhood. Malignancy rate observed in early adulthood in this small cohort matches that observed in the first decade of life, cumulatively raising tumor rate in BWS to 20% during the observation period. Further studies are warranted in this direction. [ABSTRACT FROM AUTHOR]

The pathogenic variants in the neuroblastoma‐amplified sequence (NBAS) are associated with a clinical spectrum involving the hepatic, skeletal, ocular, and immune systems. Here, we report on two unrelated subjects with a complex phenotype solved by whole‐exome sequencing, who shared a synonymous change in NBAS that was documented to affect the transcript processing and co‐occurring with a truncating change. Starting from these two cases, we systematically assessed the clinical information available for all subjects with biallelic NBAS pathogenic variants (73 cases in total). We revealed a recognizable facial profile (hypotelorism, thin lips, pointed chin, and "progeroid" appearance) determined by using DeepGestalt facial recognition technology, and we provide evidence for the occurrence of genotype–phenotype correlations. Notably, severe hepatic involvement was associated with variants affecting the NBAS‐Nter and Sec39 domains, whereas milder liver involvement and immunodeficiency were generally associated with variants located at the N‐terminus and C‐terminus of the protein. Remarkably, no patient was reported to carry two nonsense variants, suggesting lethality of complete NBAS loss‐of‐function. [ABSTRACT FROM AUTHOR]

BACKGROUND AND OBJECTIVES: The emerging association of assisted reproductive techniques (ART) with imprinting disorders represents a major issue in the scientific debate on infertility treatment and human procreation. We studied the prevalence of Beckwith-Wiedemann syndrome (BWS) in children conceived through ART to define the specific associated relative risk. METHODS: Patients with BWS born in Piemonte, Italy, were identified and matched with the general demographic data and corresponding regional ART registry. RESULTS: Between 2005 and 2014, live births in Piemonte were 379 872, including 7884 from ART. Thirty-eight patients with BWS were born, 7 from ART and 31 naturally conceived. BWS birth prevalence in the ART group was significantly higher than that of the naturally conceived group (1:1126 vs 1:12 254, P < .001). The absolute live birth risk in the ART group was 887.9 per 1 000 000 vs 83.3 per 1 000 000 in the naturally conceived group, providing a relative risk of 10.7 (95% confidence interval 4.7-24.2). During the 1997-2014 period, 67 patients were diagnosed with BWS out of 663 834 newborns (1:9908 live births). Nine out of the 67 BWS patients were conceived through ART (13.4%), and 8 were molecularly tested, with 4 having an imprinting center 2 loss of methylation, 2 with 11p15.5 paternal uniparental disomy, and 2 negative results. CONCLUSIONS: ART entails a 10-fold increased risk of BWS and could be implicated in the pathogenesis of genomic events besides methylation anomalies. These data highlight the need for awareness of ART-associated health risk. [ABSTRACT FROM AUTHOR]

Whole exome sequencing (WES) is a powerful tool to identify clinically undefined forms of intellectual disability/developmental delay (ID/DD), especially in consanguineous families. Here we report the genetic definition of two sporadic cases, with syndromic ID/DD for whom array-Comparative Genomic Hybridization (aCGH) identified a de novo copy number variant (CNV) of uncertain significance. The phenotypes included microcephaly with brachycephaly and a distinctive facies in one proband, and hypotonia in the legs and mild ataxia in the other. WES allowed identification of a functionally relevant homozygous variant affecting a known disease gene for rare syndromic ID/DD in each proband, that is, c.1423C>T (p.Arg377*) in the Trafficking Protein Particle Complex 9 ( TRAPPC9), and c.154T>C (p.Cys52Arg) in the Very Low Density Lipoprotein Receptor ( VLDLR). Four mutations affecting TRAPPC9 have been previously reported, and the present finding further depicts this syndromic form of ID, which includes microcephaly with brachycephaly, corpus callosum hypoplasia, facial dysmorphism, and overweight. VLDLR-associated cerebellar hypoplasia (VLDLR-CH) is characterized by non-progressive congenital ataxia and moderate-to-profound intellectual disability. The c.154T>C (p.Cys52Arg) mutation was associated with a very mild form of ataxia, mild intellectual disability, and cerebellar hypoplasia without cortical gyri simplification. In conclusion, we report two novel cases with rare causes of autosomal recessive ID, which document how interpreting de novo array-CGH variants represents a challenge in consanguineous families; as such, clinical WES should be considered in diagnostic testing. © 2016 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Background 22q11.2 deletion syndrome (22q11.2DS) is a common microdeletion syndrome, which occurs in approximately 1:4000 births. Familial autosomal dominant recurrence of the syndrome is detected in about 8-28% of the cases. Aim of this study is to evaluate the intergenerational and intrafamilial phenotypic variability in a cohort of familial cases carrying a 22q11.2 deletion. Methods Thirty-two 22q11.2DS subjects among 26 families were enrolled. Results Second generation subjects showed a significantly higher number of features than their transmitting parents (212 vs 129, P = 0.0015). Congenital heart defect, calcium-phosphorus metabolism abnormalities, developmental and speech delay were more represented in the second generation (P < 0.05). Ocular disorders were more frequent in the parent group. No significant difference was observed for the other clinical variables. Intrafamilial phenotypic heterogeneity was identified in the pedigrees. In 23/32 families, a higher number of features were found in individuals from the second generation and a more severe phenotype was observed in almost all of them, indicating the worsening of the phenotype over generations. Both genetic and epigenetic mechanisms may be involved in the phenotypic variability. Conclusions Second generation subjects showed a more complex phenotype in comparison to those from the first generation. Both ascertainment bias related to patient selection or to the low rate of reproductive fitness of adults with a more severe phenotype, and several not well defined molecular mechanism, could explain intergenerational and intrafamilial phenotypic variability in this syndrome. [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]

The cover image, by Alfredo Brusco et al., is based on the Original Article Whole exome sequencing is necessary to clarify ID/DD cases with de novo copy number variants of uncertain signifi cance: Two proof‐of‐concept examples, DOI: 10.1002/ajmg.a.37649. [ABSTRACT FROM AUTHOR]

Beckwith-Wiedemann syndrome (BWS) is characterized by cancer predisposition, overgrowth and highly variable association of macroglossia, abdominal wall defects, nephrourological anomalies, nevus flammeus, ear malformations, hypoglycemia, hemihyperplasia, and organomegaly. BWS molecular defects, causing alteration of expression or activity of the genes regulated by two imprinting centres (IC) in the 11p15 chromosomal region, are also heterogeneous. In this paper we define (epi)genotype-phenotype correlations in molecularly confirmed BWS patients. The characteristics of 318 BWS patients with proven molecular defect were compared among the main four molecular subclasses: IC2 loss of methylation (IC2-LoM, n=190), IC1 gain of methylation (IC1-GoM, n=31), chromosome 11p15 paternal uniparental disomy (UPD, n=87), and cyclin-dependent kinase inhibitor 1C gene (CDKN1C) variants (n=10). A characteristic growth pattern was found in each group; neonatal macrosomia was almost constant in IC1-GoM, postnatal overgrowth in IC2-LoM, and hemihyperplasia more common in UPD (P<0.001). Exomphalos was more common in IC2/CDKN1C patients (P<0.001). Renal defects were typical of UPD/IC1 patients, uretheral malformations of IC1-GoM cases (P<0.001). Ear anomalies and nevus flammeus were associated with IC2/CDKN1C genotype (P<0.001). Macroglossia was less common among UPD patients (P<0.001). Wilms' tumor was associated with IC1-GoM or UPD and never observed in IC2-LoM patients (P<0.001). Hepatoblastoma occurred only in UPD cases. Cancer risk was lower in IC2/CDKN1C, intermediate in UPD, and very high in IC1 cases (P=0.009). In conclusion, (epi)genotype-phenotype correlations define four different phenotypic BWS profiles with some degree of clinical overlap. These observations impact clinical care allowing to move toward (epi) genotype-based follow-up and cancer screening.

Background: Beckwith-Wiedemann syndrome (BWS) and hemihyperplasia (HH) are overgrowth conditions with predisposition to hepatoblastoma for which early diagnosis patients undergo cancer screening based on determination of the tumor marker α-fetoprotein (αFP). Repeated blood draws are a burden for patients with consequent compliance issues and poor adherence to surveillance protocol. We sought to analyze feasibility and reliability of αFP dosage using an analytical micromethod based on blood dried on filter paper (DBS)., Methods: Overall 143 coupled αFP determinations on plasma and DBS collected simultaneously were performed, of which 31 were in patients with hepatoblastoma predisposition syndromes and 112 were in controls. The plasma αFP dosage method was adapted to DBS adsorbed on paper matrix for newborn screening., Results: There was strong correlation between plasmatic and DBS αFP (r2 = 0.999, P < 0.001). Cohen's k coefficient for correlation was 0.96 for diagnostic cut-off of 10 U/ml (P < 0.001), commonly employed in clinical practice. The measurements on plasma and DBS were highly overlapping and consistent., Conclusion: The DBS method allowed to dose αFP reliably and consistently for the concentrations commonly employed in clinical settings for the screening of hepatoblastoma, opening new scenarios about conducting cancer screening in overgrowth syndromes.

Background: Intellectual disability affects approximately 1 to 3% of the general population. The etiology is still poorly understood and it is estimated that one-half of the cases are due to genetic factors. Cryptic subtelomeric aberrations have been found in roughly 5 to 7% of all cases., Methods: We performed a subtelomeric FISH analysis on 76 unrelated children with normal standard karyotype ascertained by developmental delay or intellectual disability, associated with congenital malformations, and/or facial dysmorphisms., Results: Ten cryptic chromosomal anomalies have been identified in the whole cohort (13,16%), 8 in the group of patients characterized by developmental delay or intellectual disability associated with congenital malformations and facial dysmorphisms, 2 in patients with developmental delay or intellectual disability and facial dysmorphisms only., Conclusion: We demonstrate that a careful clinical examination is a very useful tool for pre-selection of patients for genomic analysis, clearly enhancing the chromosomal anomaly detection rate. Clinical features of most of these patients are consistent with the corresponding emerging chromosome phenotypes, pointing out these new clinical syndromes associated with specific genomic imbalances.