Antenatal diagnosis of cardio-facio-cutaneous syndrome: Prenatal characteristics and contribution of fetal facial dysmorphic signs in utero. About a case and review of literature

Prenatal and infantile diagnosis of craniosynostosis in individuals with RASopathies

Fetuses with RASopathies can have a wide variety of anomalies including increased nuchal translucency, hydrops fetalis, and structural anomalies (typically cardiac and renal). There are few reports that describe prenatal-onset craniosynostosis in association with a RASopathy diagnosis. We present clinical and molecular characteristics of five individuals with RASopathy and craniosynostosis. Two were diagnosed with craniosynostosis prenatally, 1 was diagnosed as a neonate, and 2 had evidence of craniosynostosis noted as neonates without formal diagnosis until later. Two of these individuals have Noonan syndrome (PTPN11 and KRAS variants) and three individuals have Cardiofaciocutaneous syndrome (KRAS variants). Three individuals had single suture synostosis and two had multiple suture involvement. The most common sutures involved were sagittal (n = 3), followed by coronal (n = 3), and lambdoid (n = 2) sutures. This case series confirms craniosynostosis as one of the prenatal findings in individuals with RASopathies and emphasizes the importance of considering a RASopathy diagnosis in fetuses with multiple anomalies in combination with craniosynostosis.

Obstetrical and neonatal outcomes of cardio-facio-cutaneous syndrome: Prenatal consequences of Ras/MAPK dysregulation

We systematically delineated the prenatal phenotype, and obstetrical and neonatal outcomes of the RASopathy cardio-facio-cutaneous (CFC) syndrome. A comprehensive, retrospective medical history survey was distributed to parents of children with confirmed CFC in collaboration with CFC International, Inc. Data were collected on CFC gene variant, maternal characteristics, pregnancy course, delivery, and neonatal outcomes with the support of medical records. We identified 43 individuals with pathogenic variants in BRAF (81%), MEK1 (14%), or MEK2 (5%) genes. The median age was 8.5 years. Hyperemesis gravidarum, gestational diabetes, gestational hypertension, and preeclampsia occurred in 5/43 (12%), 4/43 (9%), 3/43 (7%), and 3/43 (7%) of pregnancies, respectively. Second and third trimester ultrasound abnormalities included polyhydramnios, macrocephaly, macrosomia, and renal and cardiac abnormalities. Delivery occurred via spontaneous vaginal, operative vaginal, or cesarean delivery in 15/42 (36%), 7/42 (16%), and 20/42 (48%), respectively. Median gestational age at delivery was 37 weeks and median birth weight was 3501 grams. Germline pathogenic vaiants had mutiple congenital consequences including polyhydramnios, renal and cardiac abnormalities, macrosomia, and macrocephaly on second and third trimester ultrasound. Elevated rates of operative delivery and neonatal complications were also noted. Understanding and defining a prenatal phenotype may improve prenatal prognostic counseling and outcomes.

Analysis of the Oral Microbiome in a Patient with Cardiofaciocutaneous Syndrome and Severe Periodontal Disease: Impact of Systemic Antibiotic Therapy

An 8-year-old girl diagnosed with cardiofaciocutaneous syndrome presented to our department with gingival pain, inflammation, and bleeding. Her medical history included hypoplasia of the corpus callosum, intellectual disability, trichothiodystrophy, global developmental delay, myopia, laryngomalacia, hypothyroidism, and osteoporosis. A diagnosis was reached of "periodontitis as a direct manifestation of systemic diseases". During 9 years of follow-up, there were exacerbation episodes with spontaneous gum bleeding, ulcers in the interdental papilla, tooth mobility, and progressive tooth loss. Some of these exacerbation episodes resolved clinically with the administration of amoxicillin and metronidazole. We therefore proposed an oral microbiome study (subgingival and saliva samples) before and after antibiotic therapy. The most abundant genera at the subgingival level before administering antibiotics were Prevotella, Streptococcus, Fusobacterium, Leptotrichia, and Aggregatibacter. Of the 94 genera sequenced, 57 were less abundant in the post-treatment state than at baseline, particularly certain Gram-negative periodontal pathogens such as Porphyromonas, Treponema, Aggregatibacter, Fusobacterium, and Campylobacter. In contrast, other genera related to oral health, such as Haemophilus, Granulicatella, and Abiotrophia, showed an increase after administering the antibiotic. In conclusion, periodontitis exacerbations as a direct manifestation of systemic disease can occasionally be controlled exclusively with systemic antibiotics, without the need for performing mechanical periodontal therapy. This clinical recovery is correlated to substantial changes in the oral microbiome, which lead to the recovery of eubiosis of the microbiota.

Fetal phenotypes of Mendelian disorders: A descriptive study from India

OBJECTIVE

Exome sequencing(ES) based diagnosis of Mendelian diseases in the fetus is limited by paucity of phenotypic information. This study reports the comprehensive phenotypes of some fetuses with Mendelian disorders.

METHODS

Next generation technology based sequencing of all coding regions of the genome(Exome sequencing) or targeted gene sequencing using Sanger or next generation platforms was performed in a cohort of deeply phenotyped, cytogenetically normal fetuses with morphological defects. Prenatal ultrasonographic phenotypes and Postmortem details including dysmorphology, histopathology, radiography were ascertained. Novel candidate genes, novel/ unusual findings and unusual genotypes in cases with confirmed Mendelian disorders are described.

RESULTS

Of the 102 fetuses sequenced, 45 (44%) achieved definitive diagnosis of a Mendelian disorder with 50 pathogenic/likely pathogenic variants. The majority (87%) were autosomal recessive, 69% families were consanguineous and 54% variants were novel. Dysmorphic syndromes, skeletal dysplasias and metabolic disorders were the commonest disease categories, ciliopathies and dystroglycanopathies commonest molecular categories. We describe the first fetal description of six monogenic diseases, and nine cases with novel histological findings. Nineteen cases had novel/ unusual findings.

CONCLUSION

This cohort demonstrates how deep fetal phenotypes of some Mendelian disorders can show novel/unusual findings which have important implications for prenatal diagnosis of these conditions. This article is protected by copyright. All rights reserved.

Lymphatic Abnormalities in Noonan Syndrome Spectrum Disorders: A Systematic Review

Noonan syndrome spectrum disorders are a group of phenotypically related conditions, resembling Noonan syndrome, caused by germline pathogenic variants in genes within the Ras/mitogen-activated protein kinase (Ras/MAPK) signalling pathway. Lymphatic dysplasia with a clinical lymphatic abnormality is one of the major features. We performed a systematic review to get more insight in (1) the prevalence of clinically lymphatic abnormalities in patients with a genetically proven Noonan syndrome spectrum disorder, (2) if a genotype-lymphatic phenotype relation can be found and describe the clinical presentation and course of the lymphatic abnormality. Most studies report patients with Noonan syndrome. Prenatally, the prevalence of increased nuchal translucency differs from 7% in patients with pathogenic PTPN11 variants to 38% in patients with pathogenic RIT1 variants, and the prevalence of pleural effusions differed from 7% in patients with pathogenic SOS1 to 29% in patients with pathogenic RIT1 variants. Postnatally, the prevalence of lymphedema differs from 16% in patients with pathogenic PTPN11 variants to 44% in patients with pathogenic SOS1 variants, and the prevalence of acquired chylothorax is 4% in patients with pathogenic RIT1 variants. Lymphatic abnormalities do occur in patients with cardiofaciocutaneous syndrome and Costello syndrome. In conclusion, Noonan syndrome spectrum disorders, Noonan syndrome in particular, are associated with lymphatic abnormalities. Combining the available published literature about genetically proven Noonan syndrome spectrum disorders, it appears likely that the lifetime prevalence of these abnormalities in Noonan syndrome is higher than the 20% that were generally accepted so far. This is increasingly important, because the activation of the RAS/MAPK pathway can be inhibited by RAS/MAPK inhibitors, and clinically severe lymphatic abnormalities may improve.

Applications of Advanced Ultrasound Technology in Obstetrics

Over the years, there have been several improvements in ultrasound technologies including high-resolution ultrasonography, linear transducer, radiant flow, three-/four-dimensional (3D/4D) ultrasound, speckle tracking of the fetal heart, and artificial intelligence. The aims of this review are to evaluate the use of these advanced technologies in obstetrics in the midst of new guidelines on and new techniques of obstetric ultrasonography. In particular, whether these technologies can improve the diagnostic capability, functional analysis, workflow, and ergonomics of obstetric ultrasound examinations will be discussed.

Antenatal diagnosis of CHARGE syndrome: Prenatal ultrasound findings and crucial role of fetal dysmorphic signs. About a series of 10 cases and review of literature

Although the prognosis of CHARGE syndrome can be highly variable from mild until severe, final diagnosis is difficult to establish in utero. The aim of our study is to compare antenatal and postnatal findings in a retrospective cohort of 10 successive patients with a positive CHD7 gene variant in order to identify the specific prenatal features for CHARGE syndrome diagnosis. Fetal ultrasound, follow-up and supplementary investigations are collected and compared to postnatal findings. Congenital heart defect (7/10), choanal atresia (7/10) and tracheoesophageal atresia (4/10) are the most frequent fetal anomalies found. Inner and external ear anomalies appear as the keystone (constant features) for prenatal diagnosis of CHARGE syndrome in fetuses with multiple anomalies and normal microarray karyotype. External ear malformations are identified in all cases by 3D ultrasound when carefully evaluated. MRI and temporal bone CT-Scan are second line useful tools to assess the diagnosis when looking for semicircular canal agenesis, arhinencephaly and/or choanal atresia. Before availability of prenatal exome sequencing in clinical routine, present findings lead to the recommendation that fetuses, with congenital heart defect (mainly septal and conotruncal), cleft lip/palate or unexplained polyhydramnios should carefully be screened for clues suggesting CHARGE syndrome using 2D and 3D ultrasound, MRI and temporal bone CT-Scan. When CHARGE syndrome is suspected with normal molecular karyotype, CHD7 gene sequencing must be offered.

The sixth international RASopathies symposium: Precision medicine-From promise to practice

The RASopathies are a group of genetic disorders that result from germline pathogenic variants affecting RAS-mitogen activated protein kinase (MAPK) pathway genes. RASopathies share RAS/MAPK pathway dysregulation and share phenotypic manifestations affecting numerous organ systems, causing lifelong and at times life-limiting medical complications. RASopathies may benefit from precision medicine approaches. For this reason, the Sixth International RASopathies Symposium focused on exploring precision medicine. This meeting brought together basic science researchers, clinicians, clinician scientists, patient advocates, and representatives from pharmaceutical companies and the National Institutes of Health. Novel RASopathy genes, variants, and animal models were discussed in the context of medication trials and drug development. Attempts to define and measure meaningful endpoints for treatment trials were discussed, as was drug availability to patients after trial completion.