Christos Yapijakis

Background: Tall stature is a multifactorial phenotypic trait encountered in the general pediatric population; however, it could constitute a manifestation of an underlying genetic and/or endocrine disorder. Mutations in genes involved in gene transcription, genomic imprinting and intracellular vesicle trafficking may lead to dysregulation of certain cellular pathways associated with different genetic syndromes with overgrowth and tall stature. Objective: Considering the facial changes that growth hormone surplus induces, it would be reasonable to hypothesize that the maxillofacial phenotype is also affected in certain genetic conditions causing excessive linear growth. The aim of this review is to assess the cephalometric data for certain genetic and/or endocrine diseases causing tall stature and overgrowth in children and discuss the potential role of cephalometric analysis in diagnosis of such phenotypes and better understanding of the underlying causing molecular mechanisms. Design: A literature search was conducted in the PubMed electronic database. The scientific articles that provided cephalometric data for genetic syndromes and conditions associated with tall stature or overgrowth were included. The following keywords were utilized: tall stature cephalometry, overgrowth syndromes cephalometry, gigantism cephalometry, hemihyperplasia cephalometric, hemihypertrophy cephalometric, Simpson–Golabi–Behmel cephalometric, Prader–Willi cephalometry, and Marfan and Klinefelter cephalometry. Results: Although the number of studies found remains limited (n = 37), the consensus findings indicate that the growth of the craniofacial complex of patients with genetic syndromes causing tall stature is affected. The cephalometric measurements assessing the cranial base, the jaws and the facial soft tissue differ from the norm and are suggestive of irregularities in both the sagittal and vertical planes. Conclusions: As the literature in this field is particularly rare, more data are required to establish relations between excessive linear growth and the maxillofacial phenotype exhibited in certain genetic and/or endocrine syndromes. Nevertheless, lateral cephalometric radiography is an extensively utilized imaging method that could potentially serve as a promising tool in the early diagnosis, phenotype–genotype comparative research and better understanding of the underlying causing molecular mechanisms of conditions associated with tall stature.

Background: Pediatric thrombosis (PT) is a rare clinical entity manifesting from neonatal life to adolescence with possibly severe clinical complications and increasing prevalence in the last decade. Its pathogenesis has been attributed to a multitude of factors, all of which share stress and inflammation as a common denominator. Although stress-induced inflammation, marked by the upregulation of proinflammatory interleukins, such as IL-1β, creates a prothrombotic environment, its relation with thrombosis remains incompletely defined, especially in the context of PT, which differs substantially from adult thrombosis. Here, we aimed to epigenetically explore the potential link between PT and stress-induced inflammation through a combinatorial approach. Methods: Initially, we bioinformatically identified candidate stress-specific miRNAs in childhood, followed by subsequent experimental assessment in serum samples of PT patients and healthy controls in relation to subjectively perceived stress levels and the functional +3953C/T genetic polymorphism of the IL1B gene, which affects the circulating levels of the proinflammatory and stress-induced interleukin 1beta (IL-1β). Results: The bioinformatic analysis identified miR-34a-5p as the most stress-specific candidate microRNA in childhood, exhibiting the highest gene-target coverage (80.6%) of the developed panel of adversity-related genes, but is also known to regulate IL1B expression. The expression of serum miR-34a-5p was not significantly influenced by subjectively perceived stress; however, its expression was significantly reduced in the presence of the T allele of the functional +3953C/T polymorphism of its target gene, IL1B, associated with increased levels of the stress-induced proinflammatory and simultaneously prothrombotic IL-1β cytokine (FC:0.57; p = 0.024). Conclusions: The observed downregulation of miR-34a-5p in the presence of the IL-1β-increasing T allele possibly indicates a dynamic regulatory relationship, which, alongside its previously established long-term downregulation in PT, renders miR-34a-5p a promising candidate molecule for bridging the biological processes of stress-associated inflammation and thrombosis. In addition, its bioinformatically yielded candidate stress-specific role holds great potential for the non-invasive evaluation of adversity-related stress in childhood.

Oral squamous cell carcinoma (OSCC) is characterized by consistently high mortality rates (≤60%) despite therapeutic advances. This is attributable to diagnostic delays arising from the asymptomatic early stages and time-consuming protocols. Hence, the establishment of reliable biomarkers for the routine assessment of the oral mucosa is imperative. MicroRNAs (miRNAs), key epigenetic regulators of gene expression, represent ideal candidates given their characteristic dysregulation across different pathologies. Here, we aimed to identify novel OSCC-specific miRNAs for the saliva-based detection of OSCC from the presymptomatic stage of early invasion. Through a multistep bioinformatic workflow, four miRNAs (miR-20b-5p, miR-484, miR-185-5p and miR-181d-5p) were identified as disease-specific since they simultaneously regulated >65% of a panel encompassing the 15 primarily overexpressed oncogenes in OSCC and a stage-specific panel including the six upregulated genes that genetically define the malignant stages of sequential oral carcinogenesis. The salivary expression of the identified miRNAs was studied in 31 OSCC patients and 31 healthy controls, using quantitative real-time PCR, followed by statistical analysis and an evaluation of the diagnostic accuracy. All studied miRNAs were significantly downregulated in the saliva of OSCC patients compared to controls (miR-484, p < 0.001; miR-181d-5p, p < 0.001; miR-185, p = 0.008; miR-20b, p = 0.026) and exhibited combinatory diagnostic performance of 95.4% (p < 0.001) for OSCC detection. Their expression remained uninfluenced by lifestyle and clinicopathological parameters, including smoking/alcohol, tumor site, grade and disease stage. The proposed 4-miRNA panel exhibits high diagnostic performance for the early, saliva-based detection of OSCC, irrespective of histopathological and lifestyle confounders, highlighting its potential as a robust non-invasive screening tool.

Background: The most common genetic cause associated with thrombophilia is Leiden mutation (G1691A) of the coagulation factor V (FV) (F5) gene. Materials and Methods: Data collected anonymously from 355 unrelated Greeks examined for the above mutation were analyzed. Bioinformatic investigation was conducted for factor V, including phylogenetic analysis, genetic network analysis, and 3D modelling of wild-type and Leiden protein. Results: Analysis confirmed the importance of F5 Leiden in thrombosis and the significance of a positive family history of thrombosis. In silico analysis of the F5 Leiden revealed a linkage between mammalian species and a potential functional interaction of F5 with 25 other genes, several of which have been associated with cardiovascular diseases. 3D modelling revealed that the Leiden mutation confers an H-bond network alteration in the functional region of FV, resulting in a hypercoagulable state. Conclusions: This study highlighted the great value of a positive family history of thrombosis and the importance of testing for this common mutation as a prevention strategy component for thrombophilia, including thrombotic brain aneurysms. Bioinformatic analysis indicated the importance of the Leiden mutation in protein structure and function. The findings of this study increase understanding of molecular and clinical features of thrombophilia and may eventually lead to better prevention of thrombosis.

Background: Oral squamous cell carcinoma (OSCC) is a highly aggressive neoplasm characterized by grim survival outcomes, despite significant therapeutic advances. Mortality rates (up to 70%) have remained unaltered for decades, predominantly due to profound diagnostic delays. These derive from the asymptomatic nature of the early stages of oral carcinogenesis and the emergence of dysplastic areas in previously benign lesions, acting as the bridge to malignant transformation. Hence, the establishment of reliable salivary biomarkers is crucial for non-invasive OSCC detection, even from the premalignant stage of dysplasia. Based on our previous bioinformatic research identifying stage-specific miRNAs throughout OSCC progression, which yielded miR-34a-5p as the most significant, we aimed to experimentally investigate its role in oral oncogenesis and explore its stage-reflecting biomarker potential for liquid biopsy. Methods: The expression of miR-34a was evaluated using quantitative real-time PCR in saliva samples from 9 patients with oral premalignant dysplastic lesions, 10 patients with OSCC and 10 healthy controls. The diagnostic accuracy of miR-34a expression profiles was assessed using ROC-curve analyses. Results: The expression of salivary miR-34a differed significantly across the studied groups, demonstrating a steep decrease in the presence of epithelial premalignant dysplasia, significant upregulation in OSCC and intermediate levels in normal oral mucosa (p < 0.001). The ROC results indicate strong diagnostic performance for the detection of oral dysplasia (AUC = 0.93; p < 0.001), OSCC (AUC = 0.77; p = 0.01) and excellent accuracy for the discrimination between premalignant and OSCC lesions (AUC = 0.98; p < 0.001). Conclusions: Our findings reveal a state-dependent dysregulation of miR-34a in oral carcinogenesis, suggesting its complex role as a pathogenetic agent that allows for malignant transformation through its diminished expression, and as a secondary reactive mechanism attempting to suppress tumor development. Salivary miR-34a holds great, stage-specific diagnostic potential, thereby reflecting the health state of oral mucosa in real time.

The most common genetic cause associated with thrombophilia is Leiden mutation (G1691A) of the coagulation factor V (F5) gene. Data collected anonymously from 355 unrelated Greeks examined for the above mutation were analyzed. Bioinformatic investigation was conducted for factor V, including phylogenetic analysis, genetic network analysis, and 3D modeling of wild-type and Leiden protein. Analysis confirmed the importance of F5 Leiden in thrombosis and the significance of a positive family history of thrombosis. In silico analysis of the F5 Leiden revealed a linkage between mammalian species and a potential functional interaction of F5 with 25 other genes, several of which have been associated with cardiovascular diseases. 3D modeling revealed that the Leiden mutation confers an H-bond network alteration in the functional region of FV, resulting in a hypercoagulable state. This study highlighted the great value of a positive family history of thrombosis and the importance of testing for this common mutation as prevention strategy components for thrombophilia, including thrombotic brain aneurysms. Bioinformatic analysis indicated the importance of the Leiden mutation in protein structure and function. The findings of this study increase understanding of molecular and clinical features of thrombophilia and may eventually lead to better prevention of thrombosis.

Infantile hemangiomas (IHs) are the most prevalent noncancerous childhood tumors, affecting up to 10% of infants. IHs develop de novo and following excessive proliferation in the first 4-9 months; they typically degenerate spontaneously in 4-7 years. While treatment is not usually required, 10-15% of cases necessitate clinical or surgical intervention due to functional impairments. Here, we present a complicated capillary IH case, from a clinical and genetic perspective. A 13-month-old patient, with free family history, presented with a cutaneous capillary-venous malformation of the thigh as well as pelvic and gluteal subcutaneous masses, resulting in urinary-bladder displacement, kidney distention, cortical thinning, pyelocaliceal dilation, and rectosigmoid displacement. Following the alleviation of the patient's symptoms and the conduction of a percutaneous nephrostomy, Sirolimus was administered for 2 years at the recommended dose. Moreover, after clinical genetic examination and informed consent of the parents, genomic DNA was extracted from a patient's peripheral blood sample and an analysis of whole-exon sequencing (WES) was performed. Treatment was successful in diminishing the pelvic and gluteal masses, but the cutaneous malformation remained. WES revealed the heterozygous c.1416A>T:p.Q472H mutation in exon 11 of the KDR gene, that encodes kinase insert domain receptor. According to the clinical presentation and the results of the genetic analysis, the patient was diagnosed with segmental capillary IH, caused by a missense pathogenic variant in the KDR gene, which impairs protein function and might also be responsible for the presented subcutaneous malformations.

Alagille syndrome (ALGS) is a rare autosomal dominant disorder with several clinical manifestations including facial, hepatic, cardiovascular, skeletal, and renal complications. ALGS is a result of pathogenic variants in either JAG1 or NOTCH2 genes, which lead to the disruption of the Notch signaling pathway. Here, we present the case of a 17-year-old female patient, clinically and genetically diagnosed with ALGS1. The 17-year-old patient, with an ALGS-free family history, was clinically diagnosed with ALGS due to liver dysfunction, cholestasis, kidney cysts, distinct craniofacial features, and skeletal malformations. Following genetic counseling and parental informed consent, genomic DNA was extracted from a sample of peripheral blood. Subsequently, whole-exome sequencing analysis was conducted, and clinically significant findings were additionally confirmed through Sanger DNA sequencing. The genetic analysis revealed the presence of a likely pathogenic donor splice variant (c.2372+1G>C) in heterozygosity with the normal allele in the JAG1 gene at intronic position 1 of 493 (affecting splicing, MAF < 0.01), which was validated by Sanger sequencing. Bioinformatic analysis indicated that the detected donor splice variant may disrupt spliceosome recognition of the canonical splice site and lead to exon skipping. Based on the clinical picture, personal/family history and genetic analyses, the patient was diagnosed with autosomal dominant ALGS type 1, caused by a de novo pathogenic mutation in the JAG1 gene. It is the first time this variant has been described in the relevant literature.

Hypokalemic periodic paralysis (hypoPP) is a rare autosomal dominant skeletal muscle ion channelopathy characterized by recurrent episodes of reversible flaccid paralysis with concurrent hypokalemia. Most of the familial hypoPP patients have missense mutations in the CACNA1S gene, which encodes the α-1S subunit of the L-type voltage-dependent calcium channel. A family with four cases of hypoPP is presented. A 67-year-old male patient with symptoms of hypokalemic paralysis was examined neurologically and genetically. His family history revealed some cases with some similar symptoms. CACNA1S gene sequencing analysis was performed in the proband and six of his relatives. The missense mutation Arg528His was identified in heterozygosity with the normal allele in the proband, three of his sons, and two other close relatives. The molecular genetic analysis confirmed the diagnosis of hypoPP in several members of the studied family.

Gorlin syndrome (GS) or basal cell nevus syndrome type 1 (BCNS1) is a rare genetic disease belonging to the spectrum of genodermatoses. Here, we present a case with BCNS1 that was caused by haploinsufficiency of PTCH1 gene, which is associated with BCNS1. A diagnosis for BCNS1 was clinically set for a 15-year-old female patient who presented with four nevoid skin lesions, four radiolucent osteolytic lesions of the jaws, macrocephaly, unilateral congenital cataracts, strabismus, hypertelorism, and calcification of the falx cerebri. The patient's parents bore no clinical findings indicative of the syndrome. Whole exome sequencing and array comparative genomic hybridization revealed a heterozygous 2.5 million base pair deletion in the long arm of chromosome 9 (9q22.32q22.33), which encompasses PTCH1 gene among others. The suggested clinical diagnosis for Gorlin syndrome type 1 was confirmed by genetic analysis. Loss-of-function mutations in PTCH1 gene, including large deletions, are known to promote the formation of neoplasms and craniomaxillofacial phenotype observed in BCNS1 by relieving the inhibition of the sonic hedgehog pathway, which is implicated in cell proliferation.