Fraser syndrome with limb reduction defect: a rare and unique anatomic variation

INTRODUCTION

Fraser syndrome, named after George Fraser, is an autosomal recessive disorder showing a highly variable interfamilial phenotypic variation, with malformations ranging from minor symptoms to lethal anomalies like renal agenesis, incompatible with survival. Limb reduction defects have not been reported to be associated with it.

CASE PRESENTATION

A 21-year-old primigravida presented to the antenatal outpatient department with a level two targeted anomaly scan report suggestive of severe oligohydramnios with suspected renal agenesis. The cranial vault bones were compressed, and orbital globes and lenses could not be visualized. Renal agenesis was confirmed due to sleeping adrenals sign, non-visualization of the urinary bladder, and Doppler of renal arteries. A detailed examination of the fetal head in the sagittal section showed the absence of an eye globe and lens, arousing suspicion of Fraser syndrome. After pregnancy termination, a complete fetal autopsy was done to look for any additional findings.

CONCLUSION

Patients who have a syndromic mix of acrofacial and urogenital abnormalities with or without cryptophthalmos should be evaluated for Fraser syndrome, which can be diagnosed by clinical examination and perinatal autopsy.

Autopsy of a 37 weeks gestation fetus with multiple malformations]

Fraser syndrome or cryptophthalmos-syndactyly syndrome is a rare genetic disease, the diagnosis of which is based on a series of major and minor clinical criteria and that can be supported by genetic tests. This article presents the case of a fetal autopsy at 37 weeks of gestation with suspicion of CHAOS syndrome (congenital obstructive syndrome of the upper airways).

Cryptophthalmos: associated syndromes and genetic disorders

PURPOSE

Cryptophthalmos is a rare congenital condition caused by anomalous eyelid development where the eyelid folds do not develop or fail to separate. Cryptophthalmos can be unilateral or bilateral and can occur in isolation or as part of an underlying syndrome. We aim to identify genetic syndromes associated with cryptophthalmos to facilitate genetic diagnosis.

METHODS

We performed a retrospective medical record review of all patients diagnosed with cryptophthalmos followed at a single center between 2000 and 2020. The analysis included medical history, clinical examination findings, and genetic testing results.

RESULTS

Thirteen patients were included, 10 (77%) males, mean age of 2.4 years. Eight (61%) had bilateral cryptophthalmos, and 4 (31%) had complete cryptophthalmos. Associated ocular abnormalities included corneal opacities (13/13, 100%), upper eyelid colobomas (12/13, 92%), and microphthalmia/clinical anophthalmia (3/13, 23%). All cases of complete cryptophthalmos had bilateral disease. An underlying clinical or molecular diagnosis was identified in 10/13 (77%) cases, including Fraser syndrome (n = 5), amniotic band syndrome (n = 1), FREM1-related disease (n = 1), Goldenhar versus Schimmelpenning syndrome (n = 1), MOTA syndrome (n = 1), and CELSR2-related disease (n = 1).

CONCLUSION

This is the first report of a possible association between cryptophthalmos and biallelic CELSR2 variants. Children with cryptophthalmos, especially those with extra-ocular involvement, should be referred for comprehensive genetic evaluation.

Heterozygous Variants in FREM2 Are Associated with Mesiodens, Supernumerary Teeth, Oral Exostoses, and Odontomas

BACKGROUND

Supernumerary teeth refer to extra teeth that exceed the usual number of dentitions. A mesiodens is a particular form of supernumerary tooth, which is located in the premaxilla region. The objective of the study was to investigate the genetic etiology of extra tooth phenotypes, including mesiodens and isolated supernumerary teeth.

METHODS

Oral and radiographic examinations and whole-exome sequencing were performed on every patient in our cohort of 122 patients, including 27 patients with isolated supernumerary teeth and 94 patients with mesiodens. A patient who had multiple supernumerary teeth also had odontomas.

RESULTS

We identified a novel (c.8498A>G; p.Asn2833Ser) and six recurrent (c.1603C>T; p.Arg535Cys, c.5852G>A; p.Arg1951His, c.6949A>T; p.Thr2317Ser; c.1549G>A; p.Val517Met, c.1921A>G; p.Thr641Ala, and c.850G>C; p.Val284Leu) heterozygous missense variants in FREM2 in eight patients with extra tooth phenotypes.

CONCLUSIONS

Biallelic variants in FREM2 are implicated in autosomal recessive Fraser syndrome with or without dental anomalies. Here, we report for the first time that heterozygous carriers of FREM2 variants have phenotypes including oral exostoses, mesiodens, and isolated supernumerary teeth.

FREM2-related Fraser syndrome with popliteal pterygium and structural central nervous system anomalies

Fraser syndrome (FS) is a rare multiple malformation disorder characterized by cryptophthalmos, characteristic craniofacial dysmorphism, cutaneous syndactyly, malformations of the respiratory and urinary tract, and anogenital anomalies. Although the characteristic presentation of FS can be detected prenatally, oligohydramnios often challenges the clinical diagnosis. Here we report on the atypical prenatal and postmortem findings of a fetus with FS caused by a novel homozygous frameshift variant in FREM2. Our study highlights the variable manifestations of the FS and expands the clinical spectrum to include popliteal pterygium and structural central nervous system anomalies.

Fraser Syndrome: A Stumbling Block for the Anaesthesiologist

Fraser syndrome is a rare autosomal recessive disorder with spectrum of malformations. Gamut of abnormal airway includes high arched palate, laryngeal atresia, hypoplasia, laryngeal stenosis etc. Laryngeal intubation difficulties have often been reported in literature. Airway management and decision process leading to emergency tracheostomy in these children has been discussed.

Clinical features and orbital anomalies in Fraser syndrome and a review of management options

Purpose:

Fraser syndrome is a rare congenital disorder comprising cryptophthalmos, syndactyly, and many times, urogenital anomalies. Herein, the authors aimed to study and report the clinical features and orbital anomalies in cases diagnosed with Fraser syndrome.

Methods:

The authors retrospectively evaluated the records of patients with Fraser syndrome who had presented to a tertiary eye care hospital in northern India in the last 2 years (from January 2019 to December 2020). The clinical features were studied, entered in MS Excel, and the data was evaluated.

Results:

Data of 15 patients with Fraser syndrome were found. Majority of the patients were males and presented in the pediatric age group. Bilateral involvement was more common, and the most common variant of cryptophthalmos was abortive. Complete and medial madarosis of the eyebrows was the most common periocular finding. Complete cryptophthalmos was associated with cystic globes, whereas abortive forms had superior symblepharon. Common systemic features included syndactyly, bifid nose, and urogenital anomaly.

Conclusion:

Fraser syndrome is an extremely rare developmental disorder; it encompasses a wide range of ocular, periocular, and orbital anomalies, along with multiple pre-existing systemic anomalies. The treating ophthalmologist should always be careful in examining these patients

Tessier cranio-facial clefts presenting to a tertiary eye care center in Northern India: Ophthalmic features and a review of management

Purpose

Tessier classification is used to classify congenital facial cleft disorders utilizing the anatomical location of the cleft and its extension. The orbital and ocular morbidities associated with the birth disorder are numerous. The authors decided to perform a retrospective analysis of the clinical features of the patients who presented to a tertiary care hospital with orbito-cranial clefts.

Methods

The authors retrospectively evaluated the records of patients with craniofacial clefts who had presented to a tertiary eye care hospital in northern India in the last 2 years (January 2019-December 2020). The clinical features were studied, entered in MS Excel, and the data were evaluated.

Results

The data of 40 patients with Tessier cleft were found. The majority of the patients were male and presented in the pediatric age group. Unilateral involvement was more common, with maxillary hypoplasia being the most common facial anomaly associated. Eyelid coloboma and euryblepharon was the most common periocular finding; lateral epibulbar dermoid and corneal opacity were the most common ocular surface anomaly. The majority of patients had presented for cosmetic correction. The syndromic association was with Goldenhar syndrome (n = 13), Fraser (n = 2), and one each of Treacher Collins, blepharocheilodontic, organoid nevus, and oculo-dento-digital syndrome. Combined clefts were also seen.

Conclusion

Tessier cleft classification is a useful tool to classify cranio-facial left anomalies. Multitudes of ocular and orbital anomalies can be associated with their different forms. Better knowledge and understanding of the classification will aid immensely in predicting the ocular defects and planning their management.

A multidisciplinary approach for prenatal diagnosis of FRASER SYNDROME-report of a novel variant in FRAS1

OBJECTIVE

With this case report, we would like to highlight the importance of a multidisciplinary approach and atypical findings of congenital high airway obstruction sequence (CHAOS), anhydramnios, and renal dysgenesis in the prenatal diagnosis of Fraser syndrome (FS).

CASE REPORT

A 25-year-old primigravida at 19 weeks of routine anomaly scan revealed abnormal sonographic findings such as fetal bilateral dysplastic small kidneys and gross oligohydramnios. The further detailed evaluation revealed that both fetal lungs were hyperechogenic with prominent (dilated) trachea and bronchi suggestive of CHAOS. Based on these findings, a diagnosis of FS was suspected. The couple was counseled and the pregnancy was terminated. The postmortem evaluation and novel homozygous variant in the FRAS1 gene confirmed the diagnosis of FS.

CONCLUSION

The diagnosis and counseling of the patient were supported by a well-coordinated, multidisciplinary approach involving an obstetrician, a fetal medicine specialist, a medical geneticist, and a fetal pathologist.

Excluding embryos with two novel mutations in FREM2 gene by the next-generation sequencing-based single nucleotide polymorphism haplotyping

Fraser syndrome is a rare autosomal recessive malformation disorder. It is characterized by cryptophthalmos, syndactyly, urinary tract abnormalities and ambiguous genitalia. This condition is due to homozygous or heterozygous mutations in the FRAS1, FREM1, FREM2, and GRIP1 genes. In the present study, we recruited a Chinese family with Fraser syndrome. Two novel mutations c.7542_7543insG and c.2689C>T in the FREM2 gene were detected in this Fraser syndrome family by PCR-based sequencing. The next-generation sequencing-based single nucleotide polymorphism haplotyping method was applied to exclude these two mutations in 9 blastocysts obtained from the patient. After obtaining consent and informing the risk, the patient received in vitro fertilization and embryo transfer treatment with an embryo carrying a heterozygous mutation. Finally, she delivered a healthy baby without any complications on March 17, 2019. In conclusion, we first reported two novel mutations in the FREM2 gene associated with the risk of Fraser syndrome. Moreover, we described a next-generation sequencing-based single nucleotide polymorphism haplotyping method to select the ‘right’ embryos from patients with Fraser syndrome for in vitro fertilization and embryo transfer treatment.

Human disease-associated extracellular matrix orthologs ECM3 and QBRICK regulate primary mesenchymal cell migration in sea urchin embryos

Sea urchin embryos have been one of model organisms to investigate cellular behaviors because of their simple cell composition and transparent body. They also give us an opportunity to investigate molecular functions of human proteins of interest that are conserved in sea urchin. Here we report that human disease-associated extracellular matrix orthologues ECM3 and QBRICK are necessary for mesenchymal cell migration during sea urchin embryogenesis. Immunofluorescence has visualized the colocalization of QBRICK and ECM3 on both apical and basal surface of ectoderm. On the basal surface, QBRICK and ECM3 constitute together a mesh-like fibrillar structure along the blastocoel wall. When the expression of ECM3 was knocked down by antisense-morpholino oligonucleotides, the ECM3-QBRICK fibrillar structure completely disappeared. When QBRICK was knocked down, the ECM3 was still present, but the basally localized fibers became fragmented. The ingression and migration of primary mesenchymal cells were not critically affected, but their migration at later stages was severely affected in both knock-down embryos. As a consequence of impaired primary mesenchymal cell migration, improper spicule formation was observed. These results indicate that ECM3 and QBRICK are components of extracellular matrix, which play important role in primary mesenchymal cell migration, and that sea urchin is a useful experimental animal model to investigate human disease-associated extracellular matrix proteins.

Pathogenesis of Anorectal Malformations in Retinoic Acid Receptor Knockout Mice Studied by HREM

Anorectal malformations (ARMs) are relatively common congenital abnormalities, but their pathogenesis is poorly understood. Previous gene knockout studies indicated that the signalling pathway mediated by the retinoic acid receptors (RAR) is instrumental to the formation of the anorectal canal and of various urogenital structures. Here, we show that simultaneous ablation of the three RARs in the mouse embryo results in a spectrum of malformations of the pelvic organs in which anorectal and urinary bladder ageneses are consistently associated. We found that these ageneses could be accounted for by defects in the processes of growth and migration of the cloaca, the embryonic structure from which the anorectal canal and urinary bladder originate. We further show that these defects are preceded by a failure of the lateral shift of the umbilical arteries and propose vascular abnormalities as a possible cause of ARM. Through the comparisons of these phenotypes with those of other mutant mice and of human patients, we would like to suggest that morphological data may provide a solid base to test molecular as well as clinical hypotheses.

Transgene-mediated skeletal phenotypic variation in zebrafish

When considering relationships between genotype and phenotype we frequently ignore the fact that the genome of a typical animal, notably including that of a fish and a human, harbours a huge amount of foreign DNA. Such DNA, in the form of transposable elements, can affect genome function in a major way, and transgene biology needs to be included in our understanding of the genome. Here we examine an unexpected phenotypic effect of the chromosomally integrated transgene fli1a-F-hsp70l:Gal4VP16 that serves as a model for transgene function generally. We examine larval fras1 mutant zebrafish (Danio rerio). Gal4VP16 is a potent transcriptional activator that is already well known for toxicity and mediating unusual transcriptional effects. In the presence of the transgene, phenotypes in the neural crest-derived craniofacial skeleton, notably fusions and shape changes associated with loss of function fras1 mutations, are made more severe, as we quantify by scoring phenotypic penetrance, the fraction of mutants expressing the trait. A very interesting feature is that the enhancements are highly specific for fras1 mutant phenotypes, occurring in the apparent absence of more widespread changes. Except for the features due to the fras1 mutation, the transgene-bearing larvae appear generally healthy and to be developing normally. The transgene behaves as a genetic partial dominant: a single copy is sufficient for the enhancements, yet, for some traits, two copies may exert a stronger effect. We made new strains bearing independent insertions of the fli1a-F-hsp70l:Gal4VP16 transgene in new locations in the genome, and observed increased severities of the same phenotypes as observed for the original insertion. This finding suggests that sequences within the transgene, for example Gal4VP16, are responsible for the enhancements, rather than the effect on neighbouring host sequences (such as an insertional mutation). The specificity and biological action underlying the traits are subjects of considerable interest for further investigation, as we discuss. Our findings show that work with transgenes needs to be undertaken with caution and attention to detail.

[Congenital high airway obstruction syndrome (CHAOS): a case report]

Le syndrome congénital d'obstruction des voies aériennes supérieures est une malformation rare qui est mortelle pour le nouveau-né après la naissance. Elle est définie comme une obstruction complète ou presque complète des voies aériennes supérieures. L'incidence réelle de la CHAOS est inconnue. Nous rapportons le cas d´une patiente de 24 ans, primipare sans antécédents médicaux ou chirurgicaux dont l´échographie de premier trimestre était sans anomalies. Au cours du deuxième trimestre l´examen échographique a montré un important œdème sous-cutané, avec un poumon hyperéchogène et hypertrophié, un cœur hypoplasique et une ascite importante associée à une oligoamnios sévères. Après avoir écarté les causes les plus fréquentes: l'iso-immunisation (Coombs indirecte négatifs), les infections (sérologies négatives) sans pouvoir disposer d'un caryotype, en raison du refus de la patiente, les résultats de l'échographie nous ont fait réfléchir à la possibilité d'un hydro-foetal secondaire au syndrome CHAOS, étant l'imagerie pathognomonique de l'hypertrophie pulmonaire avec inversion ou convexité des diaphragmes. Une IRM a été demandée montrant un probable syndrome CHAOS associé à d'autres malformations: atrésie laryngée, microphtalmie avec hypertélorisme et déviation de la cloison nasale avec absence de visualisation du tissu thymique, non identification claire de la vessie, absence de rein droit et un rein gauche hypoplasique. L´évolution de la grossesse a été marqué par la survenue À la 24^e semaine d´aménorrhée un accouchement prématuré qui a donné la naissance d´un nouveau-né avec un poids de naissance de 1475g, polymalformés présentant une ambiguïté sexuelle, avec un abdomen distendu et une polydactylie. Le nouveau-né est décédé à 3 min du post partum. Un caryotype était réalisé montrant un profil 46XX.

Novel loss of function variants in FRAS1 AND FREM2 underlie renal agenesis in consanguineous families

INTRODUCTION

Congenital anomalies of the kidney and urinary tract (CAKUT) are a group of abnormalities that affect structure of the kidneys or other structures of the urinary tract. The majority of CAKUT are asymptomatic and are diagnosed prenatally by ultrasound scanning or found incidentally in postnatal life. CAKUT varies in severity and may lead to life-threatening kidney failure and end-stage kidney disease. Renal agenesis, a severe form of CAKUT, is a congenital absence of one or both kidneys. Bilateral renal agenesis belongs to a group of prenatally lethal renal diseases and is often detected on fetal ultrasound scanning during the investigation of oligohydramnios. Approximately 40% of fetuses with bilateral renal agenesis are stillborn or die a few hours postnatally. Mutations in many renal development genes have been shown to be associated with renal agenesis.

METHODS

Six consanguineous Saudi Arabian families were recruited to study the molecular genetic causes of recurrent miscarriages and lost fetuses due to oligohydramnios, renal agenesis and other congenital anomalies. Whole exome sequencing was employed to underlying detect genetic defects.

RESULTS

Novel loss of function variants were detected in FRAS1 and FREM2. In FRAS1, a homozygous splice site variant c.9780+2T>C was found in an affected fetus, segregating form each parent. In addition, in three other families both parents were heterozygous for a frameshift variant (c.8981dupT; p.His2995Profs*3) and splice site variants (c.5217+1G>C and c.8098+2T>A), respectively. In FREM2, a homozygous nonsense variant (c.2303C>G; p.Ser768*) was found in an affected fetus, segregating from both parents. In another family, both parents carried a FREM2 heterozygous frameshift variant (c.3969delC; p.Asn1323Lysfs*5).

CONCLUSION

We describe consanguineous families with clinical features of antenatal oligohydramnios and bilateral renal agenesis, in whom we have identified novel pathogenic variants in FRAS1 and FREM2. These finding highlights the association between mutations in FRAS1 and FREM2 and antenatal/perinatal death.

Bilateral anophthalmia and intrahepatic biliary atresia, two unusual components of Fraser syndrome: a case report

BACKGROUND

Fraser syndrome or "cryptophthalmos syndrome" is a rare autosomal recessive disease. It is characterized by a group of congenital malformations such as: crytophthalmos, syndactyly, abnormal genitalia, and malformations of the nose, ears, and larynx. Although cryptophthalmos is considered as a main feature of Fraser syndrome, its absence does not exclude the diagnosis. Clinical diagnosis can be made by Thomas Criteria. Here we present the first documented case of Fraser Syndrome in Aleppo, Syria that is characterized by bilateral anophthalmia and intrahepatic biliary atresia.

CASE PRESENTATION

During pregnancy, several ultrasound scans revealed hyperechoic lungs, ascites, and unremarkable right kidney at the 19th-week visit; bilateral syndactyly on both hands and feet at the 32nd-week visit. On the 39th week of gestation, the stillborn was delivered by cesarean section due to cephalopelvic disproportion. Gross examination showed bilateral anophthalmia, bilateral syndactyly on hands and feet, low set ears, and ambiguous genitalia. Microscopic examination of the lung, spleen, liver, ovary, and kidneys revealed abnormalities in these organs.

CONCLUSION

The diagnosis of Fraser syndrome can be made prenatally and postnatally; prenatally by ultrasound at 18 weeks of gestation and postnatally by clinical examination using Thomas criteria. Moreover, intrahepatic biliary atresia was not described previously with Fraser syndrome; this recommends a more detailed pathologic study for Fraser syndrome cases.

The monster of Ascheraden: A description of syndromic cryptophthalmos by poet Daniel Hermann in "De monstroso partu…" published in Riga, 1596

In 1596, the Niclas Mollyn (Nicolaus Mollinus; 1550/55-1625) printing house in Riga, published a book in Latin, authored by Prussian poet and humanist Daniel Hermann (1543-1601) with quite an intriguing title "De monstroso partu…" or "About the monstrous birth: on August 18 of the year 1595 in the district of Ascheraden on the other side of the Duna in Livonia and on things that happen against the laws of nature. An ethical, natural and historical discourse." The "Monstroso partu…" is among the earliest books printed in Riga and the first one dedicated to a medical topic. The book contains what could be seen as the earliest known description of syndromic cryptophthalmos aka Fraser syndrome.

Two unrelated families with variable expression of Fraser syndrome due to the same pathogenic variant in the FRAS1 gene

We report on two unrelated families of Polish origin with variable expression of Fraser syndrome (FS; MIM#219000) due to homozygosity for the same pathogenic variant, c.6963_6964dup, of FRAS1. In one family, the disorder presented with perinatal and prenatal lethality. One affected female from family 2 who was followed-up for 32 years, represented a relatively favorable long-term outcome. She displayed the typical craniofacial dysmorphism, including right cryptophthalmos, cutaneous syndactyly, abnormalities of the stomathognatic system, bilateral atresia of the external ear canals resulting in conductive hearing loss, and malformations of the larynx, spleen, kidney, and genitourinary tract. Her intellectual capacities were normal. Our observations illustrate that expression and severity of FS, even when caused by the same pathogenic variant, may be quite different ranging from a lethal disorder to a condition with multiple physical malformations but normal psychomotor development. In addition, we propose that the FRAS1 c.6963_6964dup variant may be a founder mutation in the Polish population. Therefore, it would be reasonable to test specifically for this variant first in any FS1 patient of Polish ancestry.

Fraser syndrome: review of the literature illustrated by a historical adult case

Fraser syndrome (cryptophthalmos-syndactyly syndrome) is a rare autosomal recessive malformation disorder. The first description of the syndrome was reported by George Fraser in 1962. Diagnosis is based on the major and minor criteria established by van Haelst et al. in 2007. Unilateral or bilateral cryptophthalmos, syndactyly, unilateral renal agenesis, and genital anomalies are the most frequent anomalies. Several maxillofacial, oro-dental, ear-nose-throat, hormonal, and anorectal disorders are reported. Cardiac malformations and musculoskeletal anomalies are uncommon. The syndrome is related to mutations in three different genes (FRAS1, FREM2, and GRIP1) resulting in failure of the apoptosis program and disruption of the epithelial-mesenchymal interactions during embryonic development. Prenatal diagnosis is based on the detection of renal agenesis and laryngeal atresia, together with a family history. Most foetuses with severe anomalies are terminated or are stillborn. All patients or pregnancies with a diagnosis of Fraser syndrome should be referred to expert centres. A collaborative approach including anaesthetists, ENT specialists, maxillofacial surgeons, and geneticists is necessary for the management of this syndrome. In vivo and in vitro research models are available to better understand the underlying aetiology.

Genetic mutation of Frem3 does not causeFraser syndrome in mice

QBRICK, FRAS1, and FREM2 compose a family of extracellular matrix proteins characterized by twelve consecutive CSPG repeats and single or multiple Calx-β motifs. Dysfunction of these proteins have been associated with Fraser syndrome, which is characterized by malformation of skin, eyes, digits, and kidneys. FREM3 is another member of the 12-CSPG protein family. However, it remains unknown whether genetic dysfunction of FREM3 also causes Fraser syndrome or another developmental disorder. Here we investigated a Frem3 mutant mouse line generated by CRISPR/Cas9-mediated genome editing. The FREM3 mutant homozygotes were born at the expected Mendelian ratio and did not possess any defects characteristic of Fraser syndrome. These results indicate that the dysfunction of FREM3 is not associated with Fraser syndrome.

Diagnosis of Fraser syndrome missed out until the age of six months old in a low-resource setting: a case report

Background

Fraser syndrome is a rare genetic disorder that often presents with ocular, renal, genital and limb’s congenital anomalies. The prognosis of this genetic disorder depends on the severity of the combination of congenital malformations, some of which may be fatal. The diagnosis of Fraser syndrome is based on established clinical criteria and genetic tests. The criteria enabling clinical diagnosis are visible dysmorphic features present at birth, hence, Fraser syndrome can easily diagnosed at birth, except when health professionals are inexperienced in clinical recognition. Herein, we report a case of Fraser syndrome missed out at birth and fortuitously diagnosed at the age of six months in a bid to raise clinicians’ awareness, particularly in resource-limited settings.

Case presentation

We report a case of a six-month-old Cameroonian female infant, born at home and taken the following day to a primary healthcare facility for neonatal care. Her mother had no antenatal care until birth. She presented at our health center with respiratory distress and fever. She had a temperature of 38.8 °C and signs of left lung basal consolidation, suggestive of a left lower lober pneumonia, confirmed on chest x-ray. Other incidental clinical findings were several dysmorphic features like bilateral cryptophthalmos, nasal malformation, anal imperforation (with a perianal fistula), an external genital anomaly and syndactyly characteristic of Fraser syndrome associated with pneumonia. The patient responded well to intravenous antibiotics for the treatment of her pneumonia. Thereafter, she was referred to a pediatric surgeaon for surgical corrections of her bilateral cryptophthalmos, anal imperforation, external genital defect and syndactyly.

Conclusion

Here we presented a case of Fraser syndrome in a Cameroonian infant whose diagnosis was missed out at birth and fortuitously made at six months of age. In view of the serious and potentially fatal complications of this genetic disorder, we draw clinicians’ attention, especially obstetricians, midwives and pediatricians for a high index of clinical suspicion geared at a timely diagnosis and management. Also, for a timely diagnosis, health education on regular antenatal and postnatal follow ups of  the mother-infant couple respectively, cannot be overemphasized.

Endoscopic Management of Lacrimal System Dysgenesis and Dacryocystoceles in Fraser Syndrome: A Case Report and Literature Review

Background

Fraser syndrome is an autosomal recessive disorder characterized primarily by syndactyly, cryptophthalmos, urinary tract anomalies, ambiguous genitalia, and laryngeal anomalies. A 28-year-old man with Fraser syndrome presented with cryptophthalmos, microphthalmia, lacrimal system dysgenesis, and chronic sinusitis.

Objective

The patients’ clinical condition and surgical treatment are described. A literature review was conducted, and articles relevant to the case are presented.

Methods

Case report.

Results

To our knowledge, this is the first published case report of endonasal management of dacryocystoceles in a Fraser syndrome patient. The patient was treated via endoscopic endonasal marsupialization and drainage.

Conclusion

Fraser syndrome patients may initially present to many different specialties as the spectrum of clinical manifestations is broad. Physicians treating these patients should take a collaborative approach to surgical and medical management.

Locating the Level and Extent of Congenital High Airway Obstruction: Fluid in the Airway Tract as Reference Points

Described here are a series of four cases of congenital high airway obstruction in the fetus. All of the patients presented in the second trimester and all had hydrops fetalis. Three cases had bilateral hyperinflated lungs, midline shift of heart, flattening or inversion of the diaphragm, and fetal ascites. Autopsy was performed in one of these three and showed laryngeal atresia. In one fetus, there was only a unilateral huge enlargement of the lung with mediastinal shift. On autopsy, this fetus had atresia of right main bronchus. All parents had terminated the pregnancy following the prenatal diagnosis. Laryngeal atresia is an extremely rare fetal anomaly with dismal prognosis. It is important to differentiate the condition from other lesions with a more favorable prognosis, such as congenital adenomatoid malformation of the lung. Much research is needed in the future to explore the therapeutic options, including fetoscopic intervention or transplantation of stem cell-derived airways.

Variable presentation of Fraser syndrome in two fetuses and a novel mutation in FRAS1

We report on a consanguineous family with three pregnancies affected with Fraser syndrome. We note severe brachydactyly is a manifestation of Fraser syndrome and found a novel homozygous splice site variation c.3293-2A>T in FRAS1. We would like to highlight variable manifestations of Fraser syndrome and the presence of oligohydramnios in the antenatal period often makes prenatal diagnosis clinically challenging.

Syndactyly in a novel Fras1(rdf) mutant results from interruption of signals for interdigital apoptosis

BACKGROUND

Fras1 encodes an extracellular matrix protein that is critical for the establishment of the epidermal basement membrane during gestation. In humans, mutations in FRAS1 cause Fraser Syndrome (FS), a pleiotropic condition with many clinical presentations such as limb, eye, kidney, and craniofacial deformations. Many of these defects are mimicked by loss of Fras1 in mice, and are preceded by the formation of epidermal blisters in utero.

RESULTS

In this study, we identified a novel ENU-derived rounded foot (rdf) mouse mutant with highly penetrant hindlimb soft-tissue syndactyly, among other structural defects. Mapping and sequencing revealed that rdf is a novel loss-of-function nonsense allele of Fras1 (Fras1(rdf)). Focusing on the limb, we found that the Fras1(rdf) syndactyly phenotype originates from loss of interdigital cell death (ICD). Despite normal expression of bone morphogenetic protein (BMP) ligands and their receptors, the BMP downstream target gene Msx2, which is also necessary and sufficient to promote ICD, was down-regulated in the interdigital regions of Fras1(rdf) hindlimb buds.

CONCLUSIONS

The close correlation between limb bud epidermal blistering, decreased Msx2 expression, and reduced ICD in the Fras1(rdf) hindlimb buds suggests that epithelium detachment from the mesenchyme may create a physical gap that interrupts the transmission of BMP, among other signals, resulting in soft tissue syndactyly.

Mesenchymal expression of the FRAS1/FREM2 gene unit is decreased in the developing fetal diaphragm of nitrofen-induced congenital diaphragmatic hernia

PURPOSE

Developmental mutations that inhibit normal formation of extracellular matrix (ECM) in fetal diaphragms have been identified in congenital diaphragmatic hernia (CDH). FRAS1 and FRAS1-related extracellular matrix 2 (FREM2), which encode important ECM proteins, are secreted by mesenchymal cells during diaphragmatic development. The FRAS1/FREM2 gene unit has been shown to form a ternary complex with FREM1, which plays a crucial role during formation of human and rodent diaphragms. Furthermore, it has been demonstrated that the diaphragmatic expression of FREM1 is decreased in the nitrofen-induced CDH model. We hypothesized that FRAS1 and FREM2 expression is decreased in the developing diaphragms of fetal rats with nitrofen-induced CDH.

METHODS

Pregnant rats were exposed to either nitrofen or vehicle on gestational day 9 (D9), and fetuses were harvested on D13, D15 and D18. Microdissected diaphragms were divided into nitrofen-exposed/CDH and control samples (n = 12 per time-point and experimental group, respectively). Diaphragmatic gene expression levels of FRAS1 and FREM2 were analyzed by qRT-PCR. Immunofluorescence double staining for FRAS1 and FREM2 was combined with the mesenchymal marker GATA4 in order to evaluate protein expression and localization in pleuroperitoneal folds (PPFs) and fetal diaphragmatic tissue.

RESULTS

Relative mRNA expression of FRAS1 and FREM2 were significantly reduced in PPFs of nitrofen-exposed fetuses on D13 (1.76 ± 0.86 vs. 3.09 ± 1.15; p < 0.05 and 0.47 ± 0.26 vs. 0.82 ± 0.36; p < 0.05), developing diaphragms of nitrofen-exposed fetuses on D15 (1.45 ± 0.80 vs. 2.63 ± 0.84; p < 0.05 and 0.41 ± 0.16 vs. 1.02 ± 0.49; p < 0.05) and fully muscularized diaphragms of CDH fetuses on D18 (1.35 ± 0.75 vs. 2.32 ± 0.92; p < 0.05 and 0.37 ± 0.24 vs. 0.70 ± 0.32; p < 0.05) compared to controls. Confocal laser scanning microscopy revealed markedly diminished FRAS1 and FREM2 immunofluorescence in diaphragmatic mesenchyme, which was associated with reduced proliferation of mesenchymal cells in nitrofen-exposed PPFs and fetal CDH diaphragms on D13, D15 and D18 compared to controls.

CONCLUSION

Decreased mesenchymal expression of FRAS1 and FREM2 in the nitrofen-induced CDH model may cause failure of the FRAS1/FREM2 gene unit to activate FREM1 signaling, disturbing the formation of diaphragmatic ECM and thus contributing to the development of diaphragmatic defects in CDH.

Fraser syndrome with laryngeal webs: Report of two cases and a review of the literature

Fraser syndrome is a rare genetic disorder characterized by cryptophthalmos, syndactyly and laryngeal atresia. Although laryngeal webs occur uncommonly, they are the main cause of death in the first week of life in these patients. In this paper, we report two cases of Fraser syndrome with laryngeal webs. One of them was a twelve-year-old girl, primarily diagnosed with a supraglottic laryngeal web. In the course of treatment, a second web was also identified at the level of vocal cords, which is to our knowledge the first case of Fraser syndrome with two laryngeal webs in different levels.

Delivery of anesthesia and complications for children with Fraser syndrome: a review of 125 anesthetics

OBJECTIVES

To perform a retrospective, anesthesia case note review of patients with Fraser syndrome.

AIM

To identify the perioperative and postoperative anesthetic management and complications in this patient group.

BACKGROUND

Fraser syndrome is a rare, autosomal recessively inherited disorder characterized by cryptophthalmos, cutaneous syndactyly, and ambiguous genitalia. It also has variable association with cardiac, laryngeal, tracheal, and gastrointestinal abnormalities. Children with Fraser syndrome present for a variety of surgical and radiological procedures, and there are a number of single case reports in the literature.

METHODS

A retrospective case note review was undertaken on 10 children with Fraser syndrome who presented to our institution over a 30-year period. Analysis of the medical notes and general anesthetic records was undertaken, and the conduct of anesthesia, spectrum of disease, genetic markers, and perioperative complications were recorded. There were a total of 125 procedures performed under general anesthesia during this period.

RESULTS

There were a total of ten anesthetic complications in the review, all related to management of the airway. There were two accidental extubations, five recorded incidents of airway obstruction (which were relieved with continuous positive airway pressure (CPAP)) and one posttracheostomy airway bleed. One child was a difficult intubation requiring an ID 2.5 mm oral endotracheal tube (ETT), and one child was an impossible intubation that required an emergency tracheostomy to secure the airway.

CONCLUSIONS

There was a low incidence of complications with this group of patients. However, there is a relatively high incidence of difficult or impossible tracheal intubation (20%) due to glottic stenosis and one patient required an emergency tracheostomy despite no previous clinical evidence of airway narrowing.

Mild recessive mutations in six Fraser syndrome-related genes cause isolated congenital anomalies of the kidney and urinary tract

Congenital anomalies of the kidney and urinary tract (CAKUT) account for approximately 40% of children with ESRD in the United States. Hitherto, mutations in 23 genes have been described as causing autosomal dominant isolated CAKUT in humans. However, >90% of cases of isolated CAKUT still remain without a molecular diagnosis. Here, we hypothesized that genes mutated in recessive mouse models with the specific CAKUT phenotype of unilateral renal agenesis may also be mutated in humans with isolated CAKUT. We applied next-generation sequencing technology for targeted exon sequencing of 12 recessive murine candidate genes in 574 individuals with isolated CAKUT from 590 families. In 15 of 590 families, we identified recessive mutations in the genes FRAS1, FREM2, GRIP1, FREM1, ITGA8, and GREM1, all of which function in the interaction of the ureteric bud and the metanephric mesenchyme. We show that isolated CAKUT may be caused partially by mutations in recessive genes. Our results also indicate that biallelic missense mutations in the Fraser/MOTA/BNAR spectrum genes cause isolated CAKUT, whereas truncating mutations are found in the multiorgan form of Fraser syndrome. The newly identified recessive biallelic mutations in these six genes represent the molecular cause of isolated CAKUT in 2.5% of the 590 affected families in this study.

Ablepharon macrostomia syndrome: A distinct genetic entity clinically related to the group of FRAS-FREM complex disorders

Ablepharon macrostomia syndrome (AMS; OMIM 200110) is an extremely rare congenital malformation syndrome. It overlaps clinically with Fraser syndrome (FS; OMIM 219000), which is known to be caused by mutations in either FRAS1, FREM2, or GRIP1, encoding components of a protein complex that plays a role in epidermal-dermal interactions during morphogenetic processes. We explored the hypothesis that AMS might be either allelic to FS or caused by mutations in other genes encoding known FRAS1 interacting partners. No mutation in either of these genes was found in a cohort of 11 patients with AMS from 10 unrelated families. These findings demonstrate that AMS is genetically distinct from FS. It is proposed that it constitutes a separate entity within the group of FRAS-FREM complex disorders.