OBJECTIVE: We present perinatal imaging findings of a fetus with Pfeiffer syndrome and a heterozygous c.1019A>G, p.Tyr340Cys (Y340C) mutation in FGFR2 presenting a cloverleaf skull, craniosynostosis and short limbs on prenatal ultrasound mimicking thanatophoric dysplasia type II (TD2).
METHODS: A 37-year-old, gravida 2, para 1, woman underwent amniocentesis at 17 weeks of gestation because of advanced maternal age. Amniocentesis revealed a karyotype of 46,XY. However, craniofacial anomaly was found on prenatal ultrasound at 21 weeks of gestation, which showed a cloverleaf skull with severe craniosynostosis and relatively short straight long bones. Fetal magnetic resonance imaging (MRI) analysis at 22 weeks of gestation showed a cloverleaf skull, proptosis and relatively shallowing of the sylvian fissures. Prenatal ultrasound at 24 weeks of gestation showed a fetus with a cloverleaf skull with a biparietal diameter (BPD) of 6.16 cm (equivalent to 24 weeks), an abdominal circumference (AC) of 18.89 cm (equivalent to 24 weeks) and a femur length (FL) of 3.65 cm (equivalent to 21 weeks). A tentative diagnosis of TD2 was made. The pregnancy was subsequently terminated, and a 928-g malformed fetus was delivered with severe craniosynostosis, proptosis, midface retrusion, a cloverleaf skull, broad thumbs and broad big toes. The broad thumbs were medially deviated. Whole body X-ray showed a cloverleaf skull and straight long bones. However, molecular analysis of FGFR3 on the fetus revealed no mutation in the target regions. Subsequent whole exome sequencing (WES) on the DNA extracted from umbilical cord revealed a heterozygous c.1019A>G, p.Tyr340Cys (Y340C) mutation in the FGFR2 gene.
CONCLUSIONS: Fetuses with a Y340C mutation in FGFR2 may present a cloverleaf skull on prenatal ultrasound, and WES is useful for a rapid differential diagnosis of Pfeiffer syndrome from TD2 under such a circumstance.

OBJECTIVE: The pathogenesis of coronal suture craniosynostosis is often attributed to the dysregulated cellular dynamics, particularly the excessive proliferation and abnormal osteogenic differentiation of suture cells. Despite its clinical significance, the molecular mechanims of this condition remain inadequately understood. This study is dedicated to exploring the influence of the Periostin/Bone Morphogenetic Protein 1 (BMP1) axis on the growth and osteogenic maturation of Suture Mesenchymal Stem Cells (SMSCs), which are pivotal in suture homeostasis.
METHODS: Neonatal TWIST Basic Helix-Loop-Helix Transcription Factor 1 heterozygous (TWIST1+/-) mice, aged one day, were subjected to adenoviral vector-mediated Periostin upregulation. To modulate Periostin/BMP1 levels in SMSCs, we employed siRNA and pcDNA 3.1 vectors. Histological and molecular characterizations, including hematoxylin and eosin staining, Western blot, and immunohistochemistry were employed to study suture closure phenotypes and protein expression patterns. Cellular assays, encompassing colony formation, 5-ethynyl-2\'deoxyuridine, and wound healing tests were conducted to analyze SMSC proliferation and migration. Osteogenic differentiation was quantified using Alkaline Phosphatase (ALP) and Alizarin Red S (ARS) staining, while protein markers of proliferation and differentiation were evaluated by Western blotting. The direct interaction between Periostin and BMP1 was validated through co-immunoprecipitation assays.
RESULTS: In the TWIST1+/- model, an upregulation of Periostin coupled with a downregulation of BMP1 was observed. Augmenting Periostin expression mitigated craniosynostosis. In vitro, overexpression of Periostin or BMP1 knockdown suppressed SMSC proliferation, migration, and osteogenic differentiation. Periostin knockdown manifested an inverse biological impact. Notably, the suppressive influence of Periostin overexpression on SMSCs was effectively counteracted by upregulating BMP1. There was a direct interaction between Periostin and BMP1.
CONCLUSIONS: These findings underscore the significance of the Periostin/BMP1 axis in regulating craniosynostosis and SMSC functions, providing new insights into the molecular mechanisms of craniosynostosis and potential targets for therapeutic intervention.

Nickel, a common environmental hazard, is a risk factor for craniosynostosis. However, the underlying biological mechanism remains unclear. Here, we found that early-life nickel exposure induced craniosynostosis in mice. In vitro, nickel promoted the osteogenic differentiation of human mesenchymal stem cells (hMSCs), and its osteogenic ability in vivo was confirmed by an ectopic osteogenesis model. Further mRNA sequencing showed that ERK1/2 signaling and FGFR2 were aberrantly activated. FGFR2 was identified as a key regulator of ERK1/2 signaling. By promoter methylation prediction and methylation-specific PCR (MSP) assays, we found that nickel induced hypomethylation in the promoter of FGFR2, which increased its binding affinity to the transcription factor Sp1. During pregnancy and postnatal stages, AZD4547 rescued nickel-induced craniosynostosis by inhibiting FGFR2 and ERK1/2. Compared with normal individuals, nickel levels were increased in the serum of individuals with craniosynostosis. Further logistic and RCS analyses showed that nickel was an independent risk factor for craniosynostosis with a nonlinear correlation. Mediated analysis showed that FGFR2 mediated 30.13% of the association between nickel and craniosynostosis risk. Collectively, we demonstrate that early-life nickel exposure triggers the hypomethylation of FGFR2 and its binding to Sp1, thereby promoting the osteogenic differentiation of hMSCs by ERK1/2 signaling, leading to craniosynostosis.

BACKGROUND: Obstructive sleep apnea (OSA) is common in children with syndromic craniosynostosis (SC). However, objective data on the treatment of OSA in children with SC remain inadequate. This study aimed to explore the efficacy of continuous positive airway pressure (CPAP) in the management of OSA in children with SC.
METHODS: A retrospective study was performed in children with SC and OSA diagnosed by polysomnography (PSG), which was defined as an apnea hypopnea index (AHI) ≥ 1. Patients were included if they were treated with CPAP and had baseline PSG and follow-up sleep studies. Clinical and demographic data were collected from all enrolled subjects.
RESULTS: A total of 45 children with SC and OSA were identified, with an average age of 6.8 ± 4.7 years. Among them, 36 cases had moderate to severe OSA (22 with severe OSA) and received CPAP therapy followed by post-treatment sleep studies. Notably, there was a significant reduction in the AHI observed after CPAP treatment (3.0 [IQR: 1.7, 4.6] versus 38.6 [IQR: 18.2, 53.3] events/h; P < 0.001).
CONCLUSIONS: CPAP is effective and acceptable in treating severe OSA in children with SC.

Craniosynostosis is one of the most common congenital craniofacial birth defects. The genetic etiology is complex, involving syndromic developmental diseases, chromosomal abnormalities, and monogenic non-syndromic diseases. Herein, we presented a proband of craniosynostosis, who firstly displayed structural abnormalities. This research conducted dynamic ultrasound monitoring a fetus with gradually developing intrauterine growth retardation (IUGR). A novel de novo variant c.41G > A: p.W14* in SMAD6 was identified by pedigree analysis and genetic examination approaches. Recombinant plasmid carrying wild-type sequence and mutant that carries c.41G > A in SMAD6 were constructed and transfected into HEK293T cells. mRNA and protein expression of SMAD6 were reduced in SMAD6 mutants compared to the wild type. Cycloheximide (CHX) treatment and si-UPF1 transfection rescued the SMAD6 mRNA expression in the mutant construct, indicating that c.41G > A: p.W14* in SMAD6 triggered nonsense-mediated mRNA degradation (NMD) process and thus led to haploinsufficiency of the protein product. Our study demonstrated that whole-exome sequencing (WES) was a powerful tool for further diagnosis and etiological identification once fetal malformation was detected by ultrasound. Novel de novo c.41G > A: p.W14* in SMAD6 is pathogenic and potentially leads to craniosynostosis via NMD process.

Hydrocephalus is variously associated with syndromic craniosynostosis (CS), while it is randomly encountered in nonsyndromic CS. But actually, the ventriculomegaly in CS is less described. In this study, the authors aim to establish whether ventriculomegaly is common in patients with CS, in both syndromic and nonsyndromic. Retrospective measurements of Evans index (EI) were taken from thin-section computed tomography scans of 169 preoperative CS patients to assess cerebral ventricular volume. EI >0.3 indicates ventricular enlargement. A total of 169 CS patients who underwent computed tomography scan from February 2018 to December 2021 were retrospectively evaluated, including 114 males and 55 females. The average age at diagnosis was 16 months (range: 1-103 mo). Among them, 37 with syndromic CS, including 17 ventricular megaly patients, had an EI >0.3 (46.0%), and 4 of them had intracranial hypertension and needed ventriculoperitoneal shunt treatment before cranial vault remolding. One hundred and thirty-two had nonsyndromic CS (100 single-suture CS, 32 multisuture CS), and 26 of them had an EI of 0.3 or greater (19.7%). Ventrocular megaly is common among patients with CS. Early craniotomy may stabilize ventricular dilation.

Congenital craniofacial abnormalities are congenital anomalies of variable expressivity and severity with a recognizable set of abnormalities, which are derived from five identifiable primordial structures. They can occur unilaterally or bilaterally and include various malformations such as cleft lip with/without palate, craniosynostosis, and craniofacial microsomia. To date, the molecular etiology of craniofacial abnormalities is largely unknown. Noncoding RNAs (ncRNAs), including microRNAs, long ncRNAs, circular RNAs and PIWI-interacting RNAs, function as major regulators of cellular epigenetic hallmarks via regulation of various molecular and cellular processes. Recently, aberrant expression of ncRNAs has been implicated in many diseases, including craniofacial abnormalities. Consequently, this review focuses on the role and mechanism of ncRNAs in regulating craniofacial development in the hope of providing clues to identify potential therapeutic targets.

WDR35 variants are known to cause a rare autosomal recessive disorder-Cranioectodermal dysplasia (CED). The CED patients are commonly present with facial dysmorphisms (frontal bossing and low-set ears), sagittal craniosynostosis, growth retardation, dolichocephaly, skeletal deformities (brachydactyly, terminal hypoplasia of the fingers and narrow thorax), ectodermal abnormalities (sparse hair, and finger/toe nail dysplasia), nephronophthisis, retinal dystrophy and hepatic fibrosis. Diagnosis of CED can be difficult because it presents with high genetic heterogeneity. However, our understanding of the phenotype of CED caused by WDR35 variants could be more explicit, and the correlation between genotype and phenotype needs further improvement.
We report a case of the first Chinses patient of CED caused by WDR35 variants, a 3-year-and-3-month-old patient, who was admitted to our hospital with frontal bossing, growth retardation, low set ears, dolichocephaly, sparse hair, and small limbs, abnormal renal function, and moderate anemia. The child showed a novel phenotype of the ectopic testis except for presenting typical CED characteristics, and he was identified with novel compound heterozygous WDR35 variants (c.2590 C > T, p.Gln864* and c.2408_2416del, p.Asn803_Ala805del; NM_001006657). He was given iron succinate and erythropoietin to improve anemia and to inhibit repeated metabolic acidosis and hyperkalemia through acid correction, diuretic, and potassium-lowering treatments. The parents refused to accept renal replacement therapy for their child and were discharged voluntarily.
This is the first reported case of the WDR35 variants that can lead to CED and ectopic testis, which is also the first Chinese patient associated with WDR35 variants. This study expands our understanding of genotype-phenotype association in patients with WDR35 variants and provides genetic counseling for prevention and intervention in this genetic disorder. Neonatal carriers should be followed up for kidney and CED-related diseases to detect warning signs.

OBJECTIVE: To analyze the clinical and genetic characteristics of an infant with craniosynostosis.
METHODS: An infant who was admitted to Wuhan Children\'s Hospital Affiliated to Tongji Medical College of Huazhong University of Science and Technology in April 2021 due to widening of the lateral ventricles for over a month was selected as the study subject. Clinical data of the patient was collected. Peripheral blood samples were collected from the infant and her parents for chromosomal karyotyping and whole exome sequencing. Candidate variant was verified by Sanger sequencing and bioinformatic analysis. Relevant literature was retrieved from the PubMed, Wanfang and CNKI databases (up to December 2021) by using key words including ERF gene, craniosynostosis, ERF mutation, craniosynostosis and ERF-related craniosynostosis.
RESULTS: The infant, a 1-month-and-16-day-old female, was found to have sagittal synostosis by cranial X-ray radiography. Genetic testing revealed that she has harbored a heterozygous c.787C>T (p.Q263*) variant of the ERF gene, which was not found in either parent. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was predicted as pathogenic (PVS1+PS2+PM2_Supporting). In total 63 relevant cases were retrieved from the database, and a total of 64 individuals were analyzed by genetic testing. Most of the cases were sporadic and males. Multiple cranial sutures (including at least two of the sagittal suture, coronal suture, lambdoid suture, and frontal suture) were involved in 45.45% of the cases, and those with sagittal suture closure only have accounted for 20.00%. The main clinical manifestations have included hypertelorism, exophthalmos, development delay, malar dysplasia, etc. Chiari type 1 malformation may present in some patients. Variants of the ERF gene have mainly included splicing and deletional variants, and there was a strong genetic heterogeneity among the infants and their pedigrees.
CONCLUSIONS: The c.787C>T (p.Q263*) variant of the ERF gene probably underlay the craniosynostosis of this infant. Above finding has enriched the phenotype ~ genotype spectrum of the ERF gene.

Analgesia is very important for children with craniosynostosis who are undergoing cranial suture reconstruction. This study investigated the effectiveness and safety of an analgesic technique based on scalp nerve block combined with general anesthesia versus general anesthesia alone.
This was a single-center, prospective, randomized, controlled study. A total of 60 children aged 6-24 months who underwent cranial suture reconstruction were randomly divided into two groups: Group A (general anesthesia combined with scalp nerve block) and Group N (general anesthesia). The hemodynamics were recorded preoperatively, at 5 min after incision and at 1, 6 and 12 h after surgery; the pain was scored at 1, 6 and 12 h after surgery, and blood glucose was detected at 1 h after surgery.
The mean arterial pressure and heart rate at 5 min after incision and 1 h after surgery in Group N were higher than those in Group A; the blood glucose and FLACC score in Group N were higher than those in Group A; and the number of postoperative analgesic pump presses were also significantly increased in Group N.
Preoperative scalp nerve block can reduce hemodynamic fluctuation and postoperative pain in children undergoing cranial suture reconstruction for craniosynostosis. Thus, it can be safely and effectively applied in the anesthesia of these children.