Dysmorphic syndromes with overgrowth – systematic review, part 2: chromosomal and epigenetic disorders and disorders associated with dynamic mutations

Introduction
Dysmorphic syndromes are characterised by congenital anomalies affecting craniofacial features, body proportions, and organ structure. They are frequently caused by complex genetic alterations, including deletions, duplications, and microdeletions, which impede optimal growth regulation.

Aim of the study
The objective of this paper is to present a synopsis of selected dysmorphic syndromes associated with excessive growth, with particular emphasis on syndromes with confirmed or strongly suspected chromosomal aetiology or associated with DNA methylation disorders (epigenetic disorders) with dynamic mutation. The following aspects are discussed in this text: the pathogenesis of the condition, its inheritance, the characteristic clinical symptoms, the diagnostic approach and potential treatment options. The following essay will provide a comprehensive overview of the relevant literature on the subject.

Material and methods
A thorough search of various databases yielded 50,385 scientific studies. After applying strict criteria for quality and relevance, 36 studies were selected for final analysis. The selection focused on the most recent peer-reviewed studies and case studies published in English.

Results
This review identified several key chromosomal abnormalities, dynamic mutations and methylation defects linked to overgrowth syndromes. The findings consistently associated these aberrations with core clinical features such as macrocephaly, developmental delay, and musculoskeletal abnormalities. Furthermore, the study confirmed that mosaic forms and specific genetic mechanisms, such as those found in hemihyperplasia, contribute significantly to the phenotypic variability of these disorders.

Conclusions
Overgrowth syndromes are a heterogeneous group of disorders characterised by excessive growth and additional congenital anomalies. Diagnosis relies on clinical evaluation supported by molecular genetic testing. Effective management requires ongoing, collaborative care from a diverse team to promote the patient's health and development throughout their life.