Functional correlation of genome-wide DNA methylation profiles in genetic neurodevelopmental disorders.

An expanding range of genetic syndromes are characterized by genome-wide disruptions in DNA methylation profiles referred to as episignatures. Episignatures are distinct, highly sensitive, and specific biomarkers that have recently been applied in clinical diagnosis of genetic syndromes. Episignatures are contained within the broader disorder-specific genome-wide DNA methylation changes, which can share significant overlap among different conditions. In this study, we performed functional genomic assessment and comparison of disorder-specific and overlapping genome-wide DNA methylation changes related to 65 genetic syndromes with previously described episignatures. We demonstrate evidence of disorder-specific and recurring genome-wide differentially methylated probes (DMPs) and regions (DMRs). The overall distribution of DMPs and DMRs across the majority of the neurodevelopmental genetic syndromes analyzed showed substantial enrichment in gene promoters and CpG islands, and under-representation of the more variable intergenic regions. Analysis showed significant enrichment of the DMPs and DMRs in gene pathways and processes related to neurodevelopment, including neurogenesis, synaptic signaling and synaptic transmission. This study expands beyond the diagnostic utility of DNA methylation episignatures by demonstrating correlation between the function of the mutated genes and the consequent genomic DNA methylation profiles as a key functional element in the molecular etiology of genetic neurodevelopmental disorders.

Menke-Hennekam syndrome; delineation of domain-specific subtypes with distinct clinical and DNA methylation profiles.

CREB-binding protein (CBP, encoded by CREBBP) and its paralog E1A-associated protein (p300, encoded by EP300) are involved in histone acetylation and transcriptional regulation. Variants that produce a null allele or disrupt the catalytic domain of either protein cause Rubinstein-Taybi syndrome (RSTS), while pathogenic missense and in-frame indel variants in parts of exons 30 and 31 cause phenotypes recently described as Menke-Hennekam syndrome (MKHK). To distinguish MKHK subtypes and define their characteristics, molecular and extended clinical data on 82 individuals (54 unpublished) with variants affecting CBP (n = 71) or p300 (n = 11) (NP_004371.2 residues 1,705-1,875 and NP_001420.2 residues 1,668-1,833, respectively) were summarized. Additionally, genome-wide DNA methylation profiles were assessed in DNA extracted from whole peripheral blood from 54 individuals. Most variants clustered closely around the zinc-binding residues of two zinc-finger domains (ZZ and TAZ2) and within the first α helix of the fourth intrinsically disordered linker (ID4) of CBP/p300. Domain-specific methylation profiles were discerned for the ZZ domain in CBP/p300 (found in nine out of 10 tested individuals) and TAZ2 domain in CBP (in 14 out of 20), while a domain-specific diagnostic episignature was refined for the ID4 domain in CBP/p300 (in 21 out of 21). Phenotypes including intellectual disability of varying degree and distinct physical features were defined for each of the regions. These findings demonstrate existence of at least three MKHK subtypes, which are domain specific (MKHK-ZZ, MKHK-TAZ2, and MKHK-ID4) rather than gene specific (CREBBP/EP300). DNA methylation episignatures enable stratification of molecular pathophysiologic entities within a gene or across a family of paralogous genes.

Novel diagnostic DNA methylation episignatures expand and refine the epigenetic landscapes of Mendelian disorders.

Overlapping clinical phenotypes and an expanding breadth and complexity of genomic associations are a growing challenge in the diagnosis and clinical management of Mendelian disorders. The functional consequences and clinical impacts of genomic variation may involve unique, disorder-specific, genomic DNA methylation episignatures. In this study, we describe 19 novel episignature disorders and compare the findings alongside 38 previously established episignatures for a total of 57 episignatures associated with 65 genetic syndromes. We demonstrate increasing resolution and specificity ranging from protein complex, gene, sub-gene, protein domain, and even single nucleotide-level Mendelian episignatures. We show the power of multiclass modeling to develop highly accurate and disease-specific diagnostic classifiers. This study significantly expands the number and spectrum of disorders with detectable DNA methylation episignatures, improves the clinical diagnostic capabilities through the resolution of unsolved cases and the reclassification of variants of unknown clinical significance, and provides further insight into the molecular etiology of Mendelian conditions.

A conservative approach in a child with haematuria after accidental rectal impalement trauma.

We present a case of an 11-year-old boy with haematuria after traumatic rectal insertion of a sharp metal stick. It demonstrates that an expectative management with close observation can be considered in patients with rectal impalement trauma presenting with haematuria and stable vital parameters without significant injury on abdominal ultrasound.

Long-term motor and behavioral outcome after perinatal hypoxic-ischemic encephalopathy.

BACKGROUND: A cohort of children born with perinatal hypoxic-ischemic encephalopathy (HIE) was followed prospectively until school age. AIMS: To describe motor outcome and behavioral functioning of school-age children after perinatal HIE and the relationship with neonatal MRI and outcome at age 2. METHODS: Twenty-five children (19 males), born at term with perinatal HIE, were assessed at a mean age of 7 y 6 m (range 6 y 4 m-8 y 2 m). Motor ability was assessed with the Movement Assessment Battery for Children (2nd version) and behavioral functioning was assessed with the Child Behavior Checklist. Neonatal MRI was scored according to Barkovich classification. RESULTS: Of the 25 included children, eight had cerebral palsy (CP). Of the 17 children without CP, nine had impaired motor ability (of which 3 scored definitely abnormal), and four had behavioral problems. There was a significant difference in motor performance (p = 0.008) between children with normal and children with abnormal neonatal MRI. Two (of four) children with normal motor ability and seven (of 14) children with normal neurological examination at age 2 showed impaired motor ability at school age. CONCLUSIONS: Half of the children without CP had impaired motor ability at school age. A normal outcome after HIE at young age does not necessarily imply a good outcome at school age, even when neonatal MRI does not show any abnormalities. More research is needed on the behavioral and cognitive consequences of HIE at school age and on the consequences for quality of life for children with and without CP.