Single-suture craniosynostosis and the epigenome: current evidence and a review of epigenetic principles

Craniosynostosis in Isfahan, Iran: A Cross-Sectional Study

Background

Craniosynostosis is the premature closure of cranial sutures. According to the literature, several factors are related to this disorder. Due to the relatively high prevalence in Iran and a lack of related studies in this region, this study was designed to determine the characteristics of a group of these patients in this region.

Methods

This cross-sectional study was performed from 2016 to 2019 at two tertiary referral hospitals for children in Isfahan, Iran. Studied variables included: age, sex, birth weight, type of craniosynostosis, concurrent anomalies, parents' age, father's job, fetus position, maternal parity, history of maternal smoking during the pregnancy, use of fertility assistant treatments, and history of maternal endocrine disorders.

Results

We had 125 infants, including 82 (65.6%) males and 43 (34.4%) females. The most common type was metopic (29%). The most common concurrent disorder was congenital heart defects (43.2% of patients). The mean age of infants was 0.62SD0.59 years. Gender distribution showed a significant difference (p value = 0.006). While the metopic (n = 31) type was significantly more common in boys, the coronal type was female predominant (n = 14). The mean age of fathers was 33.08SD5.66 and mothers, was 29.02SD5.70 with no significant difference (p value = 0.669 and 0.149, respectively). Other evaluated factors also didn't show a significant difference.

Conclusion

Craniosynostosis is more prevalent in boys, especially the metopic type. Coronal type has a female predilection. The most common subtype is metopic. The most common concurrent congenital disorder is congenital heart defects.

Physiology and Clinical Manifestations of Pathologic Cranial Suture Widening

Cranial sutures are complex structures integrating mechanical forces with osteogenesis which are often affected in craniofacial syndromes. While premature fusion is frequently described, rare pathological widening of cranial sutures is a comparatively understudied phenomenon. This narrative review aims to bring to light the biologically variable underlying causes of widened sutures and persistent fontanelles leading to a common outcome. The authors herein present four syndromes, selected from a literature review, and their identified biological mechanisms in the context of altered suture physiology, exploring the roles of progenitor cell differentiation, extracellular matrix production, mineralization, and bone resorption. This article illustrates the gaps in understanding of complex craniofacial disorders, and the potential for further unification of genetics, cellular biology, and clinical pillars of health science research to improve treatment outcomes for patients.

A novel pathogenic variant of DNMT3A associated with craniosynostosis: a case report of Heyn-Sproul-Jackson syndrome

Pathogenic variants of DNMT3A have been implicated in Tatton-Brown-Rahman syndrome, an overgrowth disorder with macrocephaly and intellectual disability. However, there are recent reports of variants in the same gene giving rise to an opposing clinical phenotype presenting with microcephaly, growth failure, and impaired development-named Heyn-Sproul-Jackson syndrome (HESJAS). Here, we present a case of HESJAS caused by a novel pathogenic variant of DNMT3A. A five-year-old girl presented with severe developmental delay. Perinatal and family history were non-contributory. Physical exam showed microcephaly and facial dysmorphic features, and neurodevelopmental assessments revealed profound global developmental delay. Brain magnetic resonance imaging findings were normal; however, brain 3D computed tomography revealed craniosynostosis. Next generation sequencing revealed a novel heterozygous variant in DNMT3A (NM_175629.2: c.1012_1014 + 3del). The patient's parents did not carry the variant. In this report, a novel feature associated with HESJAS (craniosynostosis) is described, along with a more detailed account of clinical manifestations than those in the original report.

The current understanding of germline predisposition in non-syndromic sagittal craniosynostosis: a systematic review

PURPOSE

The objective of this literature review was to provide a comprehensive and up-to-date overview of the current understanding of the genetic etiology for non-syndromic sagittal craniosynostosis.

METHODS

Using the PubMed database and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), we systematically reviewed relevant records on germline genetics in children with non-syndromic sagittal craniosynostosis.

RESULTS

Two hundred two records were identified, of which 25 were included following title and abstract screening and subsequent full-text review. The 25 records in combination included 829 children with non-syndromic sagittal craniosynostosis. A likely pathogenic or pathogenic germline variant was reported for 9.8% of the 827 patients for whom germline genetic testing was performed. The reported variants were distributed across 50 different genes, with more than one variant detected in 13 genes.

CONCLUSION

Based on the existing literature, genetic predisposition is likely to play a role in at least 9% of children with non-syndromic sagittal craniosynostosis. Future studies will benefit from international consensus in terms of diagnostic nomenclature and a higher level of standardization across study methodologies and bioinformatic approaches.

Defining a Taxonomical Map for Craniosynostoses: An Integrated Nomenclature for Interdisciplinary Workflow and Problem Mapping in Craniosynostoses Management: A Feasibility Study

Craniosynostoses is a complex clinical and management challenge. This is further complicated by varying phenotypes and specific challenges. Most complex craniosynostoses are approached and managed the same way despite the clinical variability. The goals for craniofacial surgery are common, but the nomenclature based on phenotype, genotype, sutural involvement, or syndromic nature does not shed light on the management workflow. The descriptive diagnosis and terminologies do not highlight the priorities and the operational issues, and most specialists dealing with these conditions remain in their field of tunnelled vision. In this article, the authors propose a concept of categorization based on initial patient presentation. In addition, the etiology and the treatment status, if available, are incorporated along with the presentation. The utility of our proposed categorization is to create a goal-based universal language among various specialists involved.