Craniofrontonasal dysplasia (CFND) is a rare X-linked craniofacial malformation that manifests with midline defects such as hypertelorism, coronal craniosynostosis, and extracranial skeletal anomalies. The standard timeline for surgical management typically includes early cranial vault remodeling and later orbital hypertelorism correction, most commonly through orbital box osteotomies at mixed dentition. For infants presenting with unicoronal craniosynostosis (UCS), fronto-orbital advancement (FOAR) is often used to correct asymmetry and allow for cranial expansion. However, in patients with known or expected need for future hypertelorism correction, the authors argue that traditional FOAR imposes a significant scar burden and disruption to surgical planes that may complicate future reconstruction. As an alternative, the authors propose endoscopic-assisted fronto-orbital distraction osteogenesis for those patients presenting with UCS and CFND.

Craniofrontonasal syndrome (CFNS; MIM #304110) is a rare craniofacial disorder characterized by hypertelorism, a broad nasal root with a bifid nasal tip, orofacial clefting, and genital malformations caused by pathogenic variants in the X-linked gene EFNB1 (MIM *300035). CFNS exhibits sex-specific heterogeneity, with increased severity in females likely secondary to cellular interference related to random X-inactivation, resulting in mosaic EFNB1 expression. Previous studies have identified over 140 variants in EFNB1, but approximately 20% of CFNS have negative molecular testing, either due to a yet undiscovered causal gene or causal variants in regulatory regions not covered by traditional genetic testing methodologies. Here, we report a two-generation family with a clinical diagnosis of CFNS and negative clinical molecular testing. Research short-read genome testing identified a 2-Mb inversion together with two smaller deletions (13- and 7-bp), about 106-Kb downstream of EFNB1, which cosegregated with CFNS. Patient-derived fibroblasts reprogrammed into induced pluripotent stem cells (iPSCs) demonstrated two distinct iPSC populations in affected females, where one or other of the two X chromosomes was inactivated. In vitro assays further demonstrated that iPSCs with the active X chromosome bearing the inversion, exhibited a significant increase in EFNB1 expression, suggesting allelic imbalance contributes to mosaic EFNB1 expression. These findings nominate a novel causal variant type of CFNS, conclude a 43-year diagnostic odyssey for an affected family, and offer new hope for family planning for affected individuals.

Craniofrontonasal syndrome (CFNS) is an X-linked developmental disorder caused by loss of function variants (LOFVs) in the ephrin B1 (EFNB1) gene located on Xq13.1. In CFNS, unlike in other X-linked disorders, females with heterozygous EFNB1 pathogenic variants (PVs) have a severe phenotype, whereas males carrying hemizygous EFNB1 PVs have a mild phenotype. Here we report a female CFNS patient who was diagnosed with the typical features of CFNS as a new-born. Chromosomal analysis revealed a de novo pericentric inversion of one X chromosome; inv(X)(p22q13). Molecular testing for EFNB1 mutations and a SNP-array test for genomic imbalances returned negative results. We identified the inversion breakpoints using whole genome sequencing (WGS). One of the breakpoints was about 97 kbp downstream of the 3' end of the EFNB1 gene, separating a potential EFNB1 enhancer region from the EFNB1 gene. To our knowledge, this is the first case of CFNS caused by a large structural variant, altering the genomic and regulatory context of EFNB1.

To block the transmission of Cranio-facial-nasal syndrome (CFNS) caused by a large deletion of the EFNB1 gene through preimplantation genetic testing for monogenic disorders (PGT-M). A patient with craniofacial deformities and his parents who had visited Shiyan People's Hospital in June 2020 were selected as the study subjects. The child underwent whole exome sequencing (WES) and qPCR validation. After genetic counseling, PGT-M was chosen for the reproductive blockage. This study was approved by the Ethics Committee of the Hospital (Ethics No.: sysrmyy-087). The child was diagnosed with CFNS due to a heterozygous deletion of exons 1-5 of the EFNB1 gene through WES and qPCR, which showed a X-linked dominant inheritance. The mother underwent ovarian stimulation with a modified PPOS protocol, which has yielded 11 oocytes. After ICSI fertilization, 4 blastocysts were formed, and MALBAC whole genome amplification was performed on the trophoblast biopsy cells, and SNP haplotypes of the family members and embryos were analyzed to indirectly determine the presence of maternal pathogenic haplotypes. Chromosomal copy number variation analysis was conducted through next-generation sequencing to screen for euploid embryos, resulting in the identification of two euploid embryos that did not carry the mutation of the EFNB1 gene. The first transfer was unsuccessful, but after adjusting the transfer timing through endometrial receptivity assessment (ERA), clinical pregnancy was achieved. Prenatal diagnosis at 19 weeks excluded the EFNB1 gene exons 1-5 deletion in the fetus. A healthy girl was delivered by Cesarean section at 38+6 weeks, and Q-PCR confirmed she has no aforementioned EFNB1 gene deletion. This study has successfully blocked the transmission of CFNS caused by a large deletion of the EFNB1 gene (exons 1-5) using a PGT-M strategy, which may provide reference for the intervention of similar genomic variations that cannot be directly detected.

Background: Craniofrontonasal dysplasia (CFND) is an X-linked developmental disorder caused by mutations in the EFNB1 gene located on chromosome Xq13. This gene encodes ephrin-B1, a ligand for Eph receptors, which is involved in cell signaling pathways and the development of the nervous and vascular systems, as well as facial and cranial structures. Paradoxically, the syndrome manifests with greater severity in heterozygous females, whereas hemizygous males typically present with mild or no abnormalities. Methods and Results: We report the case of a late preterm female neonate with dysmorphic features at birth, who subsequently developed necrotizing enterocolitis (NEC) caused by thrombosis of the superior mesenteric artery. Extensive bowel resection led to short bowel syndrome, resulting in cholestatic liver disease, malabsorption, and growth impairment. Array-comparative genomic hybridization (a-CGH) analysis identified a ~791 Kb microduplication at Xq13.1, encompassing the EFNB1 gene, confirming the diagnosis of CFND. She was enrolled in a multidisciplinary follow-up program and, at 2 years of age, presents with marked growth and neurodevelopmental delay. Conclusions: This report describes a rare association between CFND and NEC caused by superior mesenteric artery thrombosis. To the best of our knowledge, no previously reported cases of CFND associated with thrombosis or thrombosis-related conditions, including NEC, have been identified. This is based on a literature review (2004-2025) performed using PubMed and Scopus, and limited to English-language case reports and reviews.