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.

The Fraser Complex Proteins (Frem1, Frem2, and Fras1) Can Form Anchoring Cords in the Absence of AMACO at the Dermal-Epidermal Junction of Mouse Skin.

AMACO (VWA2 protein), secreted by epithelial cells, is strongly expressed at basement membranes when budding or invagination occurs in embryos. In skin, AMACO associates with proteins of the Fraser complex, which form anchoring cords. These, during development, temporally stabilize the dermal-epidermal junction, pending the formation of collagen VII-containing anchoring fibrils. Fraser syndrome in humans results if any of the core members of the Fraser complex (Fras1, Frem1, Frem2) are mutated. Fraser syndrome is characterized by subepidermal blistering, cryptophthalmos, and syndactyly. In an attempt to determine AMACO function, we generated and characterized AMACO-deficient mice. In contrast to Fraser complex mutant mice, AMACO-deficient animals lack an obvious phenotype. The mutually interdependent basement membrane deposition of the Fraser complex proteins, and the formation of anchoring cords, are not affected. Furthermore, hair follicle development in newborn AMACO-deficient mice showed no gross aberration. Surprisingly, it appears that, while AMACO is a component of the anchoring cords, it is not essential for their formation or function.

Oral and Craniofacial Anomalies of Fraser Syndrome:Prosthetic Management.

Fraser syndrome (FS, MIM 219000) is a rare autosomal disorder characterized by systemic and oro-facial malformation, usually comprising cryptophthalmos, laryngeal malformations, syndactyly, and urogenital defects. We presented a 21-year-old FS case with partial missing teeth seeking aesthetic dental treatment. Clinical examination revealed bilateral cryptophthalmos, extensive syndactyly of hands and feet broad nose with the depressed nasal bridge, and surgically corrected bilateral cleft lip. She presented class III jaw relation and reduced the vertical height of the face. Prosthetic rehabilitation of the patient was done with upper and lower overlay dentures made from acrylic resin (VIPI BLOCK TRILUX®, VIPI Industria, Pirassununga, SP, Brazil) using computer-aided design (CAD) and computer-aided manufacturing (CAM) process. At the follow-up visit, the patient presented improved aesthetics and function. Proper management and rehabilitation of FS patients are challenging, but standard guidelines for oral health management are currently lacking. This article presents a case of Fraser syndrome presenting oral and craniofacial anomalies, and prosthetic rehabilitation was done. We also provided recommendations for the optimal oral health care for the FS patients. Functional adaptation and rehabilitation have significant roles in the various functions, survival, and quality of the life of FS patients. Integrated medicaldental care is needed in such patients with support from family members, friends, and colleagues.

The first adolescent case of Fraser syndrome 3, with a novel nonsense variant in GRIP1.

Fraser syndrome is characterized by cryptophthalmos, syndactyly and other autopod defects, and abnormalities of the respiratory and urogenital tracts. Biallelic variants in GRIP1 can cause Fraser syndrome 3 (FRASRS3), and five unrelated FRASRS3 cases have been reported to date. Four cases are fetuses with homozygous truncating variants. The remaining case is an almost 9-year-old Turkish girl compound heterozygous for a truncation variant and a possibly frame-shift intragenic deletion. We present a 15.5-year old Pakistani boy with homozygous truncating variant c.1774C>T (p.Gln592Ter). Of the hallmarks of the disease, the boy has cryptophthalmia, midface retrusion, very low anterior hairline, hair growth on temples extending to the supraorbital line and also on alae nasi, agenesis of right kidney, and cutaneous syndactyly of fingers and toes but no symptoms in any other organs, including lungs, anorectal system, genitalia, and umbilical system. This case is the oldest known individual with FRASRS3, and our findings show that a homozygous GRIP1 truncating variant can manifest with a non-lethal phenotype than in the reported cases with such variants, expanding the phenotypic and mutational spectrum of GRIP1.

A homozygous mutation p.Arg2167Trp in FREM2 causes isolated cryptophthalmos.

Cryptophthalmos (CO, MIM: 123570) is rare congenital anomalies of eyelid formation, which can occur alone or in combination with multiple congenital anomalies as part of Fraser syndrome (FS) or Manitoba Oculotrichoanal syndrome. Causal mutations have been identified for these syndromes but not in the isolated cases. Here, we described two patients from two unrelated Chinese families: one with unilateral isolated CO, while the other with unilateral CO and renal agenesis. A novel homozygous mutation (c.6499C>T: p.Arg2167Trp) and compound heterozygote mutations (c.15delG; c.6499C>T: p.Arg2167Trp) in FREM2 (NM_172862) were identified for the two patients, respectively. The deletion mutation c.15delG resulted in a frameshift and triggered the nonsense-mediated mRNA decay. For the shared missense mutation, p.Arg2167Trp altered a conserved residue and was predicted to affect protein structure by in silico analysis. Functional analysis revealed that Arg2167Trp mutant decreased its interaction with FRAS1 related extracellular matrix 1 (FREM1) and impaired the function of the FRAS1-FRAS1 related extracellular matrix 1 (FREM2)-FREM1 ternary complex required for normal embryogenesis. Furthermore, considering that mutation (c.5914C>T: p.Glu1972Lys) in FREM2 causes FS, a severe systemic disorder, we also compared these two different missense mutations. Our results showed that p.Arg2167Trp had a weaker effect in interrupting interactions between FREM2 and FREM1 than FS-associated missense mutation p.Glu1972Lys. Overall, our data demonstrate that the homozygous mutation p.Arg2167Trp in FREM2 causes isolated CO, which will facilitate our better understanding of the molecular mechanisms underlying the disease.

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.

Characteristic dental pattern with hypodontia and short roots in Fraser syndrome.

Fraser syndrome (FS) is a rare autosomal recessive multiple congenital malformation syndrome characterized by cryptophthalmos, cutaneous syndactyly, renal agenesis, ambiguous genitalia, and laryngotracheal anomalies. It is caused by biallelic mutations of FRAS1, FREM2, and GRIP1 genes, encoding components of a protein complex that mediates embryonic epithelial-mesenchymal interactions. Anecdotal reports have described abnormal orodental findings in FS, but no study has as yet addressed the orodental findings of FS systematically. We reviewed dental radiographs of 10 unrelated patients with FS of different genetic etiologies. Dental anomalies were present in all patients with FS and included hypodontia, dental crowding, medial diastema, and retained teeth. A very consistent pattern of shortened dental roots of most permanent teeth as well as altered length/width ratio with shortened dental crowns of upper incisors was also identified. These findings suggest that the FRAS1-FREM complex mediates critical mesenchymal-epithelial interactions during dental crown and root development. The orodental findings of FS reported herein represent a previously underestimated manifestation of the disorder with significant impact on orodental health for affected individuals. Integration of dentists and orthodontists into the multidisciplinary team for management of FS is therefore recommended.

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.

Loss-of-function mutations in FREM2 disrupt eye morphogenesis.

Cryptophthalmos is a rare congenital disorder characterized by ocular dysplasia with eyelid malformation. Complete cryptophthalmos is characterized by the presence of continuous skin from the forehead over the eyes and onto the cheek, along with complete fusion of the eyelids. In the present study, we characterized the clinical manifestations of three patients with isolated bilateral cryptophthalmos. These patients shared the same c.6499C > T missense mutation in the FRAS1-related extracellular matrix protein 2 (FREM2) gene, while each individual presented an additional nonsense mutation in the same gene (Patient #1, c.2206C > T; Patient #2, c.5309G > A; and Patient #3, c.4063C > T). Then, we used CRISPR/Cas9 to generate mice carrying Frem2R725X/R2156W compound heterozygous mutations, and showed that these mice recapitulated the human isolated cryptophthalmos phenotype. We detected FREM2 expression in the outer plexiform layer of the retina for the first time in the cryptophthalmic eyes, and the levels were comparable to the wild-type mice. Moreover, a set of different expressed genes that may contribute secondarily to the phenotypes were identified by performing RNA sequencing (RNA-seq) of the fetal Frem2 mutant mice. Our findings extend the spectrum of FREM2 mutations, and provide insights into opportunities for the prenatal diagnosis of isolated cryptophthalmos. Furthermore, our work highlights the importance of the FREM2 protein during the development of eyelids and the anterior segment of the eyeballs, establishes a suitable animal model for studying epithelial reopening during eyelid development and serves as a valuable reference for further mechanistic studies of the pathogenesis of isolated cryptophthalmos.

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.

Reconstruction of Unilateral Incomplete Cryptophthalmos in Fraser Syndrome.

A full-term baby girl with Fraser syndrome was born with right incomplete cryptophthalmos. On examination, the globe was completely covered with skin with partially formed eyelids laterally. At 3 years of age, she underwent an evisceration with orbital implant and reconstruction of the eyelids and fornices using the pre-existing scleral remnant. Custom ocular prosthetic fitting was performed 5 weeks postoperatively. At 4 years follow up, she continued to successfully retain an ocular prosthesis.

Fraser syndrome: features suggestive of prenatal diagnosis in a review of 38 cases.

OBJECTIVE: Fraser syndrome (FS) is a rare malformation recessive disorder. Major criteria are cryptophtalmos, syndactyly, respiratory, genital and urinary tract anomalies. Few prenatal presentations have been reported. METHOD: We analyzed the prenatal and postnatal fetal phenotype in 38 cases of FS, including 25 pregnancy termination cases, 8 intra-uterine death cases and 4 cases that died after birth. RESULTS: Including both prenatal and postnatal fetal phenotypic evaluation, all cases presented dysmorphic features with nose and ear dysplasia. Renal anomalies and syndactyly were present in 37/38 cases, cryptophtalmos in 36/38, airways anomalies in 30/37 and genital anomalies in 30/35 cases. Anomalies of the abdominal wall such as low set umbilicus and omphalocele were found in 31 cases. Among the 26 cases for which ultrasound data were available, detectable anomalies included oligohydramnios (22), ascites/hydrops (9), renal anomalies (20), evidence for high airways obstruction (11), ophthalmologic anomalies (4), ear dysplasia (2) and syndactyly (2). CONCLUSION: This study shows that the postnatal phenotype of FS is very specific, whereas oligohydramnios hampers the prenatal recognition of the cardinal FS diagnosis criteria. Association of oligohydramnios, kidney agenesis and CHAOS should lead to consider this diagnosis. © 2016 John Wiley & Sons, Ltd.

fras1 shapes endodermal pouch 1 and stabilizes zebrafish pharyngeal skeletal development.

Lesions in the epithelially expressed human gene FRAS1 cause Fraser syndrome, a complex disease with variable symptoms, including facial deformities and conductive hearing loss. The developmental basis of facial defects in Fraser syndrome has not been elucidated. Here we show that zebrafish fras1 mutants exhibit defects in facial epithelia and facial skeleton. Specifically, fras1 mutants fail to generate a late-forming portion of pharyngeal pouch 1 (termed late-p1) and skeletal elements adjacent to late-p1 are disrupted. Transplantation studies indicate that fras1 acts in endoderm to ensure normal morphology of both skeleton and endoderm, consistent with well-established epithelial expression of fras1. Late-p1 formation is concurrent with facial skeletal morphogenesis, and some skeletal defects in fras1 mutants arise during late-p1 morphogenesis, indicating a temporal connection between late-p1 and skeletal morphogenesis. Furthermore, fras1 mutants often show prominent second arch skeletal fusions through space occupied by late-p1 in wild type. Whereas every fras1 mutant shows defects in late-p1 formation, skeletal defects are less penetrant and often vary in severity, even between the left and right sides of the same individual. We interpret the fluctuating asymmetry in fras1 mutant skeleton and the changes in fras1 mutant skeletal defects through time as indicators that skeletal formation is destabilized. We propose a model wherein fras1 prompts late-p1 formation and thereby stabilizes skeletal formation during zebrafish facial development. Similar mechanisms of stochastic developmental instability might also account for the high phenotypic variation observed in human FRAS1 patients.

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.

A novel mutation in the FRAS1 gene in a patient with Fraser syndrome.

Fraser Syndrome (FS) is a rare disease with autosomal recessive inheritance characterized by cryptophthalmus, cutaneous syndactyly, laryngeal and urogenital anomalies. Mutations in the genes FRAS1 and FREM2 encoding components of a protein complex of the extracellular matrix, and recently also mutations in GRIP1 have been found to be causative for FS. We present here molecular and clinical findings of a patient with FS who was found to have a novel homozygous frameshift mutation c.9739delA, p.(T3247Pfs*44) in exon 63 of FRAS1 gene. Further testing confirmed the heterozygous carrier status of parents.

Frontal Encephalocele Associated With a Bilateral Tessier Number Three Cleft and Fraser Syndrome.

Oblique craniofacial clefts and encephaloceles are each rare conditions, and only a few instances of these findings in combination have been described. Each pathologic entity presents a unique reconstructive challenge. The authors report the case of a male infant who presented with a large right frontoencephalocele and bilateral Tessier number 3 clefts. A review of the pertinent literature, including specific considerations related to perioperative management and technical aspects of the surgical approach, is discussed.

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.

[About a case of Fraser syndrome. Autopsy of a 37 weeks gestation fetus with multiple malformations]. / A propósito de un caso de síndrome de Fraser. Autopsia de un feto de 37 semanas de gestación con múltiples malformaciones.

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).