Prenatal sonographic findings and prognosis of craniosynostosis diagnosed during the fetal and neonatal periods

Mid‑trimester ultrasound findings in tricho‑hepato‑enteric syndrome: A case report

Tricho-hepato-enteric (THES) syndrome is a severe congenital diarrheal disorder. It is caused by homozygous or compound heterozygous mutations in the SKIC3 (THES1) or SKIC2 (THES2) gene. Primary manifestations include nine clinical signs: Ιntractable diarrhea, hair abnormalities, facial dysmorphism, IUGR, immunodeficiency, skin abnormalities, liver disease, congenital cardiac defects and platelet anomalies in the 96 cases reported to date. Α case of early, isolated severe fetal growth restriction with a non-placental etiology is presented, consistent with postnatal findings reported in the literature. Furthermore, this case introduces two novel prenatal ultrasound findings: Severe echogenic bowel, and dolichocephaly in contribution to the limited body of knowledge. Trio-whole exome sequencing (WES) analysis revealed that the embryo was compound heterozygous for two mutations in SKIC2, both of which were of parental origin. The report also discusses potential mechanisms underlying the observed ultrasound signs, highlighting that the expanded application of WES in prenatal settings will add more cases of sporadic disorder.

Current Understanding of Crouzon Syndrome Pathophysiology and New Therapeutic Approaches

Crouzon syndrome (CS) is a rare genetic disorder characterized by the premature fusion of cranial sutures, leading to craniofacial abnormalities and potential neurological complications. CS is caused primarily by gain-of-function mutations in the FGFR2 gene and, less commonly, by mutations in the FGFR3 gene (specifically associated with CS with acanthosis nigricans). Managing CS requires a multidisciplinary approach, combining early and later surgical interventions to prevent intracranial hypertension and correct craniofacial deformities, along with ongoing care to address associated complications. Recent advancements in CS classification on the basis of cranial suture involvement have refined phenotype-genotype correlations, improving personalized therapeutic strategies. This review aims to provide a comprehensive and updated overview of CS, including detailed insights into molecular genetics and biological mechanisms underlying its pathophysiology, and a depiction of the clinical features, diagnosis, and surgical aspects of CS. In addition, we delve into innovative theranostic views, where molecular genetic testing allows the design of personalized noninvasive therapeutic approaches based on innovative biotechnologies, including RNA-interference molecules, pharmacological modulation of FGFR signaling pathways, and recombinant proteins. These advancements underscore the importance of integrating molecular studies into diagnostic and therapeutic protocols to increase the precision and effectiveness of nonsurgical treatments for CS.

Prenatal Diagnosis of Nonsyndromic Craniosynostosis: A Scoping Review

Craniosynostosis is rarely diagnosed in utero. Prenatal diagnosis has the potential to improve patient outcomes and streamline care, however, and is becoming more feasible as technology improves. The objective of this study is to examine existing literature on prenatal diagnosis of nonsyndromic craniosynostosis.

In accordance with PRISMA guidelines, Embase, Cochrane, and PubMed were searched for articles discussing prenatal diagnosis of nonsyndromic craniosynostosis via imaging studies. Studies that exclusively examined syndromic craniosynostosis were excluded.

Diagnostic criteria for prenatal diagnosis of craniosynostosis.

The search identified 2129 articles. And 12 articles met inclusion criteria and were included in the final analysis. Ten of 12 included studies (83.3%) utilized biometric data (biparietal and occipitofrontal diameter, cranial index) to analyze fetal head shape. Two of 12 studies (16.7%) utilized specific ultrasonic markers to identify craniosynostosis including a "brain shadowing sign." One study (8.3%) created a systematic quantitative screening methodology with formal shape analysis for identification of sagittal synostosis. In all included studies, identification of craniosynostosis was possible in the second or third trimesters.

Prenatal diagnosis of craniosynostosis is feasible and has the potential to improve patient outcomes. Creation of screening protocols and standardized metrics for sonographic diagnosis are important next steps in craniosynostosis care.

Emphasis on Early Prenatal Diagnosis and Perinatal Outcomes Analysis of Apert Syndrome

Apert syndrome is an inherited condition with autosomal dominant transmission. It is also known as acrocephalosyndactyly type I, being characterized by a syndrome of craniosynostosis with abnormal head shape, facial anomalies (median hypoplasia), and limb deformities (syndactyly, rhizomelic shortening). The association can suspect the prenatal diagnosis of these types of anomalies. The methodology consisted of revising the literature, by searching the PubMed/Medline database in which 27 articles were selected and analyzed, comprising 32 cases regarding the prenatal diagnosis of Apert syndrome. A series of ultrasound parameters, the anatomopathological abnormalities found, the obstetric results, and the genetic tests were followed. The distribution of imaging results (US, MRI) identified in the analyzed cases was as follows: skull-shaped abnormalities were evident in 96.8% of cases, facial abnormalities (hypertelorism 43.7%, midface hypoplasia 25%, proptosis 21.8%), syndactyly in 87.5%, and cardiovascular abnormalities in 9.3%. The anomalies detected by the ultrasound examination of the fetus were confirmed postnatally by clinical or gross evaluation or imaging. The management of these cases requires an early diagnosis, an evaluation of the severity of the cases, and appropriate parental counseling.

Plea for systematic prenatal genes panel testing when facing isolated craniosynostosis on fetal imaging

BACKGROUND

Prenatal diagnosis of craniosynostosis remains rare and challenging, easier in syndromes with craniosynostosis due to the association with other sonographic anomalies. Crouzon syndrome is the most frequent syndrome with craniosynostosis but is difficult to detect antenatally because of mild skull deformation without specific associated anomaly during gestation.

CASE

This report presents the case of a fetus with Crouzon syndrome related to the variant c.1646A>C in exon 14 of the FGFR2 gene and presenting with apparently isolated scaphocephaly on fetal US.

CONCLUSION

This observation supports the interest of systematic prenatal panel genes testing when facing an apparently isolated craniosynostosis diagnosed on fetal imaging, even if non-syndromic craniosynostosis are much more frequent in such situation.

TEACHING POINTS

Syndromic craniosynostosis can appear as apparently isolated form on fetal imaging. Systematic prenatal panel genes testing can be contributive even when facing an apparently isolated craniosynostosis on fetal imaging.

Efficacy of Systematic Early-Second-Trimester Ultrasound Screening for Facial Anomalies: A Comparison between Prenatal Ultrasound and Postmortem Findings

Second-trimester 2D ultrasound (US) assessment of the fetal anatomy, as proposed by worldwide guidelines, allows detecting the majority of fetal malformation. However, the detection rates of fetal facial anomalies seem to still be low, mostly in cases of isolated facial malformation. The purpose of this research was to assess and analyze the concordance between the antenatal imaging findings from second-trimester US screening and the results of fetal postmortem autopsy. Between January 2010 and January 2020, there were 43 cases where fetuses with prenatal ultrasound diagnosis of a face abnormality, associated or not with a genetic syndrome or chromosomal disorder, following intrauterine death (IUD) or termination of pregnancy (TOP) after the 13 weeks of pregnancy, underwent autopsy in the Pathological Anatomy section of Bari Polyclinic specializing in feto-placental autopsies. The diagnosis of the fetal facial defects at ultrasound was compared with the findings at autopsy in all cases. A very high level of agreement between prenatal ultrasound and autopsy findings was found for facial abnormalities associated with genetic syndromes or numerical abnormality of chromosomes. A lower level of concordance was instead found in isolated facial defects or those associated with other organ anomalies, but not associated with genetic syndrome or numerical chromosome anomaly. A detailed examination of aborted fetuses led to successful quality control of early-second-trimester ultrasound detection of facial anomalies; however, it was less accurate for the isolated ones. It is, thus, reasonable to propose a systematic early-second-trimester prenatal ultrasound screening for facial anatomy by operators specialized in fetal medicine field, using 2D, 3D, and 4D techniques (two-, three-, and four-dimensional ultrasound).

De Novo Heterozygous Mutation in FGFR2 Causing Type II Pfeiffer Syndrome

Pfeiffer syndrome (PS) is an autosomal dominant disorder with three subtypes stemming from heterozygous mutations in the fibroblast growth factors FGFR1 and FGFR2. The subtypes overlap with heterogeneous clinical manifestations and variable prognosis dependent on neurological and respiratory compromise that impact short- and long-term outcomes and survival. We present a male, term infant with type II PS that was diagnostically suspected antenatally based on three-dimensional ultrasonographic findings that were confirmed postnatally by craniofacial tomography and magnetic resonance imaging. A new generation sequencing panel identified a unique de novo FGFR2, c.335 A > G p. Tyr112Cys variant, the first of its kind, and features that closely aligned with subtype II PS. Initial molecular results categorized the mutation as nonpathogenic, but it was later reclassified as pathogenic. Antenatal, multidisciplinary parental counseling about the tentative diagnosis and prognosis facilitated postnatal decisions that culminated in an informed choice for palliative care and early demise.

Early Prenatal Ultrasound and Molecular Diagnosis of Apert Syndrome: Case Report with Postmortem CT-Scan and Chondral Plate Histology

Background Apert syndrome is characterized by craniosynostosis, midface hypoplasia and symmetric syndactyly. Case report: A 36-year-old mother, G2P1 underwent an ultrasound scan at 19 week's gestation. There was craniosynostosis, brachi-turricephaly and bilateral hand syndactyly. Genomic DNA from amniocentesis revealed the mutation C758C>Gp. (Pro to Arg substitution) at 252 of the exon 8 of the FGFR2 encoding for Apert syndrome. The pregnancy was terminated. Femoral chondral plate histology showed an increased interstitial matrix between bony trabeculae. Compared with normal, the trabeculae were thinner, more irregular with numerous osteoclasts suggesting abnormal bone remodeling. Hands and feet had an abrupt transition between resting and proliferating cartilage. Conclusion: Apert syndrome has increased intertrabecular matrix, thin trabeculae, increased remodeling, and irregular transition between the maturing and mineralization zones in the femur, and abnormal abrupt transition between the resting and proliferating cartilage in the fingers and toes.

The clinical manifestations, molecular mechanisms and treatment of craniosynostosis

Craniosynostosis is a major congenital craniofacial disorder characterized by the premature fusion of cranial suture(s). Patients with severe craniosynostosis often have impairments in hearing, vision, intracranial pressure and/or neurocognitive functions. Craniosynostosis can result from mutations, chromosomal abnormalities or adverse environmental effects, and can occur in isolation or in association with numerous syndromes. To date, surgical correction remains the primary treatment for craniosynostosis, but it is associated with complications and with the potential for re-synostosis. There is, therefore, a strong unmet need for new therapies. Here, we provide a comprehensive review of our current understanding of craniosynostosis, including typical craniosynostosis types, their clinical manifestations, cranial suture development, and genetic and environmental causes. Based on studies from animal models, we present a framework for understanding the pathogenesis of craniosynostosis, with an emphasis on the loss of postnatal suture mesenchymal stem cells as an emerging disease-driving mechanism. We evaluate emerging treatment options and highlight the potential of mesenchymal stem cell-based suture regeneration as a therapeutic approach for craniosynostosis.

Fetal Trigonocephaly (Strawberry Skull) in Early Pregnancy

Trigonocephaly was previously described prenatally in association with severe abnormalities, mostly observed after 18 weeks of gestation. We describe our experience with this finding in early pregnancy, between 14 and 17 weeks of gestation. Our series includes 18 cases of trigonocephaly with several etiologies; trisomy 18, de novo translocation, thanatophoric dysplasia, and open spina bifida without hydrocephalus. Two fetuses had no other significant abnormalities and a spontaneous normalization of the skull shape was observed on follow-up. Both had normal genetic testing and postnatal outcome. These two cases represent a new phenomenon of an isolated transient form with normal outcome.

Antenatal Ultrasound Imaging for Analysis of Human Craniosynostosis

The cranial sutures can be imaged sonographically in the fetus as early as the end of the first trimester; however, fetal position and maternal body habitus can present significant challenges to clear visualization. Antenatal identification of craniosynostosis is important for delivery planning, and there are a number of available ultrasound techniques and imaging signs to assist with accurate diagnosis of both single suture craniosynostosis and syndromic multisutural fusions.

Differential diagnosis of syndromic craniosynostosis: a case series

Purpose

Syndromic craniosynostosis is a rare genetic disease caused by premature fusion of one or multiple cranial sutures combined with malformations of other organs. The aim of this publication is to investigate sonographic signs of different syndromic craniosynostoses and associated malformations to facilitate a precise and early diagnosis.

Methods

We identified in the period of 2000–2019 thirteen cases with a prenatal suspected diagnosis of syndromic craniosynostosis at our department. We analyzed the ultrasound findings, MRI scans, genetic results as well as the mode of delivery, and postnatal procedures.

Results

Eight children were diagnosed with Apert Syndrome, two with Saethre Chotzen syndrome, one with Crouzon syndrome, and one with Greig cephalopolysyndactyly syndrome. One child had a mutation p.(Pro253Leu) in the FGFR2 gene. We identified characteristic changes of the head shape as well as typical associated malformations.

Conclusion

Second trimester diagnosis of syndromic craniosynostosis is feasible based on the identified sonographic signs. In case of a suspected diagnosis a genetic, neonatal as well as surgical counseling is recommended. We also recommend to offer a fetal MRI. The delivery should be planned in a perinatal center.

Prenatal diagnosis of Pfeiffer syndrome type 2 with increased nuchal translucency

Pfeiffer syndrome (PS) is a rare autosomal dominant genetic disorder characterized by craniosynostosis, broad thumbs / toes. Here, we report a case of PS type 2 with increased nuchal translucency in early trimester.

Prenatal diagnosis of Pfeiffer syndrome and role of three-dimensional ultrasound: case report and review of literature

Purpose/aim of the study: We report a rare case of autosomal dominant genetic syndrome "Pfeiffer", which is part of the group of acrocephalosyndactyly, with an annual incidence <1/100,000. Three forms are known. Type I is the less common form and it is characterized by moderate-severe mediofacial hypoplasia usually with normal cognitive development. Conversely, types 2 and 3 are more common and they are associated with more severe signs and complications with a more unfavorable prognosis. The type 3 form due to the presence of a cloverleaf skull distinguishes type 2.Materials and methods: Thirty-eight-year-old primigravida was referred to our center, at 28 weeks of gestation due to borderline ventriculomegaly, macrocrania, and a short femur. First trimester screening for chromosomopathies and CF-DNA was low risk; II trimester screening ultrasound showed the presence of "short femur" and macrocrania.Result: Our ultrasound evaluation, assisted by 3D ultrasound, showed cloverleaf skull, turricephaly, moderate ventriculomegaly (13 mm), hypertelorism and exophthalmos, low ear implantation, mild rhizomelia. Ultrasound depicts Pfeiffer syndrome or other acrocephalosyndactyly syndromes (Apert syndromes, Saethre-Chotzen) or other syndromic forms of craniosynostosis like Crouzon syndrome. The NGS panel for molecular analysis of genes involved in skeletal dysplasias showed the mutation of the FGFR2 gene, de novo.Conclusions: Using three-dimensional (3D) ultrasound, it is easier to distinguish rare syndromes characterized by facial dysmorphisms such as exophthalmos, mediofacial hypoplasia, and craniosynostosis.

Towards automated extraction of 2D standard fetal head planes from 3D ultrasound acquisitions: A clinical evaluation and quality assessment comparison

INTRODUCTION

Clinical evaluation of deep learning (DL) tools is essential to compliment technical accuracy metrics. This study assessed the image quality of standard fetal head planes automatically-extracted from three-dimensional (3D) ultrasound fetal head volumes using a customised DL-algorithm.

METHODS

Two observers retrospectively reviewed standard fetal head planes against pre-defined image quality criteria. Forty-eight images (29 transventricular, 19 transcerebellar) were selected from 91 transabdominal fetal scans (mean gestational age = 26 completed weeks, range = 20+5-32+3 weeks). Each had two-dimensional (2D) manually-acquired (2D-MA), 3D operator-selected (3D-OS) and 3D-DL automatically-acquired (3D-DL) images. The proportion of adequate images from each plane and modality, and the number of inadequate images per plane was compared for each method. Inter and intra-observer agreement of overall image quality was calculated.

RESULTS

Sixty-seven percent of 3D-OS and 3D-DL transventricular planes were adequate quality. Forty-five percent of 3D-OS and 55% of 3D-DL transcerebellar planes were adequate. Seventy-one percent of 3D-OS and 86% of 3D-DL transventricular planes failed with poor visualisation of intra-cranial structures. Eighty-six percent of 3D-OS and 80% of 3D-DL transcerebellar planes failed due to inadequate visualisation of cerebellar hemispheres. Image quality was significantly different between 2D and 3D, however, no significant difference between 3D-modalities was demonstrated (p < 0.005). Inter-observer agreement of transventricular plane adequacy was moderate for both 3D-modalities, and weak for transcerebellar planes.

CONCLUSION

The 3D-DL algorithm can automatically extract standard fetal head planes from 3D-head volumes of comparable quality to operator-selected planes. Image quality in 3D is inferior to corresponding 2D planes, likely due to limitations with 3D-technology and acquisition technique.

IMPLICATIONS FOR PRACTICE

Automated image extraction of standard planes from US-volumes could facilitate use of 3DUS in clinical practice, however image quality is dependent on the volume acquisition technique.

Treatment of infants with craniofacial malformations

Infants with craniofacial malformations (CFMs) are at increased risk of various clinical problems, including respiratory and feeding disorders, the result of which may be long-lasting. An improvement in clinical care can be achieved by prenatal diagnosis and interdisciplinary birth preparation. Feeding problems may particularly be stressful for the family and require a team approach involving nursing staff, speech therapists and nutritional specialists to anticipate, avoid and treat sequelae such as failure to thrive or recurrent aspirations. Special techniques (eg, optimisation of breast feeding, alternative feeding methods or manual orofacial therapy) may be used individually to improve feeding competence; supplemental nutrition via a nasogastric or gastrostomy tube may be temporarily necessary to ensure adequate weight gain. The high prevalence of respiratory disorders in infants with craniofacial abnormalities requires anticipation and screening to prevent growth failure and neurological deficits. Treatment of upper airway obstruction varies widely, strategies can be divided into non-surgical and surgical, and in those aimed at widening the pharyngeal space (eg, prone position, palatal plates, craniofacial surgery) and those bridging the narrow upper airway (eg, nasopharyngeal airway, modified palatal plate, pneumatic airway stenting, tracheostomy). The complex management of an infant with CFM should be performed by a multidisciplinary team to offer specialised support and care for affected families.

Prenatal genetic diagnosis of cranioectodermal dysplasia in a Polish family with compound heterozygous variants in WDR35

The ciliary chondrodysplasias represent a group of clinically and genetically heterogeneous disorders that affect skeleton development. Cilia are organelles that project from the surface of many cell types and play an important role during prenatal and postnatal human development. Cranioectodermal dysplasia (Sensenbrenner syndrome, CED) is a ciliopathy primarily characterized by craniofacial, skeletal, and ectodermal abnormalities. To date six genes have been associated with CED: IFT122, WDR35, WDR19, IFT140, IFT43, and IFT52. Prenatal diagnosis of CED is challenging, and genetic testing can facilitate making a correct diagnosis. Here, we report on a family with two male siblings affected by CED: a 3.5 year-old patient and his 2 year-old brother. Molecular analysis of the proband at 1 year of age revealed compound heterozygous variants in WDR35: c.3G>A [p.(Met1-Ala30delinsMetfsTer4)] and c.2522A>T [p.(Asp841Val)]. Ultrasound examination during the second pregnancy revealed an increased nuchal translucency of 4.5 mm and a hypoplastic nasal bone at 12 weeks of gestation. Prenatal diagnostic testing was offered because of an increased risk for chromosomal abnormalities and recurrence risk for CED. Prenatal genetic analysis of a chorionic villus sample detected the WDR35 variants previously identified in the elder brother. This is the first report of a prenatal genetic diagnosis in CED.

Sonographic indicators of isolated fetal sagittal craniosynostosis during pregnancy

INTRODUCTION

The antenatal diagnosis of sagittal craniosynostosis can be challenging, but there are several published papers describing a traumatic outcome to both the affected fetus and the mother during delivery of a scaphocephalic child. The antenatal imaging from affected children was collected along with the mother's obstetric history. The aim of this study was to identify antenatal ultrasound features that may assist the diagnosis of sagittal synostosis before birth, to enable appropriate delivery planning and avoid both maternal and fetal trauma during birth.

METHODS

Antenatal ultrasound scans in both the second and third trimesters were traced for 36 children with sagittal synostosis. The initially diagnostic CT scans were also sourced. A delivery history was collected from the hospital case notes where available.

RESULTS

The affected group showed a statistically significant reduction in cephalic index during the second half of pregnancy compared with the normal population which became slightly more brachycephalic (P = 0.001). Regression analysis showed an average reduction in cephalic index of 0.57 units per month. There was also a much higher rate of malpresentation and surgical deliveries in the affected group than the normal population. There was a relationship between sagittal craniosynostosis and breech presentation and an associated higher rate of surgical deliveries.

CONCLUSION

It is possible to detect sagittal synostosis in the third trimester of pregnancy which may assist with delivery planning.

Imaging in craniosynostosis: when and what?

PURPOSE

Currently, the interest on craniosynostosis in the clinical practice is raised by their increased frequency and their genetic implications other than by the still existing search of less invasive surgical techniques. These reasons, together with the problem of legal issues, make the need of a definite diagnosis for a crucial problem, even in single-suture craniosynostosis (SSC). Although the diagnosis of craniosynostosis is primarily the result of physical examination, craniometrics measuring, and observation of the skull deformity, the radiological assessment currently plays an important role in the confirmation of the diagnosis, the surgical planning, and even the postoperative follow-up. On the other hand, in infants, the use of radiation or the need of sedation/anesthesia raises the problem to reduce them to minimum to preserve such a delicate category of patient from their adverse effects.

METHODS, RESULTS AND CONCLUSIONS

This review aims at summarizing the state of the art of the role of radiology in craniosynostosis, mainly focusing on indications and techniques, to provide an update not only to pediatric neurosurgeons or maxillofacial surgeons but also to all the other specialists involved in their management, like neonatologists, pediatricians, clinical geneticists, and pediatric neurologists.