-
Journal of Medical Genetics Mar 2024encodes an intracellular inhibitor of the bone morphogenetic protein (BMP) signalling pathway. Until now, rare heterozygous loss-of-function variants in were...
BACKGROUND
encodes an intracellular inhibitor of the bone morphogenetic protein (BMP) signalling pathway. Until now, rare heterozygous loss-of-function variants in were demonstrated to increase the risk of disparate clinical disorders including cardiovascular disease, craniosynostosis and radioulnar synostosis. Only two unrelated patients harbouring biallelic variants presenting a complex cardiovascular phenotype and facial dysmorphism have been described.
CASES
Here, we present the first two patients with craniosynostosis harbouring homozygous variants. The male probands, both born to healthy consanguineous parents, were diagnosed with metopic synostosis and bilateral or unilateral radioulnar synostosis. Additionally, one proband had global developmental delay. Echocardiographic evaluation did not reveal cardiac or outflow tract abnormalities.
MOLECULAR ANALYSES
The novel missense (c.[584T>G];[584T>G], p.[(Val195Gly)];[(Val195Gly)]) and missense/splice-site variant (c.[817G>A];[817G>A], r.[(817g>a,817delins[a;817+2_817+228])];[(817g>a,817delins[a;817+2_817+228])], p.[(Glu273Lys,Glu273Serfs*72)];[(Glu273Lys,Glu273Serfs*72)]) both locate in the functional MH1 domain of the protein and have not been reported in gnomAD database. Functional analyses of the variants showed reduced inhibition of BMP signalling or abnormal splicing, respectively, consistent with a hypomorphic mechanism of action.
CONCLUSION
Our data expand the spectrum of variants and phenotypic spectrum associated with homozygous variants of to include craniosynostosis.
Topics: Humans; Male; Craniosynostoses; Radius; Ulna; Mutation, Missense; Smad6 Protein; Synostosis
PubMed: 38290823
DOI: 10.1136/jmg-2023-109151 -
JNMA; Journal of the Nepal Medical... Oct 2023Klippel-Feil syndrome is a rare congenital bone disorder characterised by a triad of short neck, low posterior hairline and limited lateral bending of the neck with an...
UNLABELLED
Klippel-Feil syndrome is a rare congenital bone disorder characterised by a triad of short neck, low posterior hairline and limited lateral bending of the neck with an annual incidence of 1 in 40,000 live births. It has remained an obscure term in the medical literature because of its variability in presentation and wide spectrum of anomalies involving multiple organ systems. It is unusual to find a case that has all three classical triad features. Here, we present a case of a 9-month-old infant who manifests not only all three classical triad features associated with Klippel-Feil syndrome but also demonstrates the presence of congenital heart disease, scoliosis, and renal ectopia. An early comprehensive evaluation of a suspected case is essential for diagnosis and counselling which impacts its prognosis, helps minimize social stigma and affords parents the opportunity to consider cosmetic surgery as an option, should they choose to pursue it.
KEYWORDS
case reports; congenital; heart diseases; Klippel-Feil syndrome; scoliosis.
Topics: Infant; Humans; Klippel-Feil Syndrome; Scoliosis; Heart Defects, Congenital; Bone and Bones; Kidney; Rare Diseases
PubMed: 38289771
DOI: 10.31729/jnma.8303 -
Turkish Neurosurgery 2024To evaluate and compare open cranial vault remodeling (OCVR) and endoscopy-assisted craniosynostosis surgery (EACS) in patients with non-syndromic craniosynostosis and...
AIM
To evaluate and compare open cranial vault remodeling (OCVR) and endoscopy-assisted craniosynostosis surgery (EACS) in patients with non-syndromic craniosynostosis and to develop an algorithm to determine the most appropriate surgery for each patient.
MATERIAL AND METHODS
Eighty-five children with craniosynostosis who underwent surgery between 2010 and 2022 were retrospectively analyzed. Demographic data, comorbidities, and peri-operative findings of the patients were recorded. Pre- and post-operative comparisons were made between predetermined measurement techniques for each deformation. In addition, measurements were obtained by computed tomography (CT) or 3D stereophotogrammetric (3DSPG) methods from eligible patients and compared with one another.
RESULTS
In our study, 61 patients underwent EACS, whereas 24 underwent OCVR. The operating time of OCVR was approximately 54.4 minutes longer than that of EACS (p < 0.001). The intra-operative blood loss was around 139 ml higher in OCVR (p < 0.001). The length of hospital stay for patients who underwent EACS was shorter at 8.4 days on average (p < 0.001). Surprisingly, 5 complications were observed in OCVR compared with 7 in EACS. While the cosmetic outcome of EACS was superior in most of the pathologyspecific measurement techniques, the metopic index increased only in patients with metopic synostosis after both surgical operations. Still, this increase was lower in EACS than in OCVR.
CONCLUSION
This study suggests that endoscopic craniosynostosis surgery has lower estimated blood loss and operation and hospitalization times, as well as comparable cosmetic results compared with open vault surgeries on long-term follow-up. CT and 3DSPG methods can help distinguish between different types of measurement techniques for synostoses. However, no significant differences were found in the comparisons since 3DSPG can also provide reliable measurements comparable to those on CT during follow-up.
Topics: Child; Humans; Infant; Retrospective Studies; Skull; Craniosynostoses; Endoscopy; Blood Loss, Surgical; Treatment Outcome
PubMed: 38282588
DOI: 10.5137/1019-5149.JTN.43011-22.2 -
Human Genetics Feb 2024The fibroblast growth factor receptors comprise a family of related but individually distinct tyrosine kinase receptors. Within this family, FGFR2 is a key regulator in...
The fibroblast growth factor receptors comprise a family of related but individually distinct tyrosine kinase receptors. Within this family, FGFR2 is a key regulator in many biological processes, e.g., cell proliferation, tumorigenesis, metastasis, and angiogenesis. Heterozygous activating non-mosaic germline variants in FGFR2 have been linked to numerous autosomal dominantly inherited disorders including several craniosynostoses and skeletal dysplasia syndromes. We report on a girl with cutaneous nevi, ocular malformations, macrocephaly, mild developmental delay, and the initial clinical diagnosis of Schimmelpenning-Feuerstein-Mims syndrome, a very rare mosaic neurocutaneous disorder caused by postzygotic missense variants in HRAS, KRAS, and NRAS. Exome sequencing of blood and affected skin tissue identified the mosaic variant c.1647=/T > G p.(Asn549=/Lys) in FGFR2, upstream of the RAS signaling pathway. The variant is located in the tyrosine kinase domain of FGFR2 in a region that regulates the activity of the receptor and structural mapping and functional characterization revealed that it results in constitutive receptor activation. Overall, our findings indicate FGFR2-associated neurocutaneous syndrome as the accurate clinical-molecular diagnosis for the reported individual, and thereby expand the complex genotypic and phenotypic spectrum of FGFR-associated disorders. We conclude that molecular analysis of FGFR2 should be considered in the genetic workup of individuals with the clinical suspicion of a mosaic neurocutaneous condition, as the knowledge of the molecular cause might have relevant implications for genetic counseling, prognosis, tumor surveillance and potential treatment options.
Topics: Female; Humans; Neurocutaneous Syndromes; Genotype; Mutation, Missense; Nevus, Sebaceous of Jadassohn; Craniosynostoses; Receptor, Fibroblast Growth Factor, Type 2
PubMed: 38265560
DOI: 10.1007/s00439-023-02634-1 -
Genes Dec 2023Nager syndrome is a rare human developmental disorder characterized by craniofacial defects including the downward slanting of the palpebral fissures, cleft palate, limb... (Review)
Review
Nager syndrome is a rare human developmental disorder characterized by craniofacial defects including the downward slanting of the palpebral fissures, cleft palate, limb deformities, mandibular hypoplasia, hypoplasia or absence of thumbs, microretrognathia, and ankylosis of the temporomandibular joint. The prevalence is very rare and the literature describes only about a hundred cases of Nager syndrome. There is evidence of autosomal dominant and autosomal recessive inheritance for Nager syndrome, suggesting genetic heterogeneity. The majority of the described causes of Nager syndrome include pathogenic variants in the gene, which encodes a component of the spliceosome; therefore, the syndrome belongs to the spliceosomopathy group of diseases. The diagnosis is made on the basis of physical and radiological examination and detection of mutations in the gene. Due to the diversity of defects associated with Nager syndrome, patients require multidisciplinary, complex, and long-lasting treatment. Usually, it starts from birth until the age of twenty years. The surgical procedures vary over a patient's lifetime and are related to the needed function. First, breathing and feeding must be facilitated; then, oral and facial clefts should be addressed, followed by correcting eyelid deformities and cheekbone reconstruction. In later age, a surgery of the nose and external ear is performed. Speech and hearing disorders require specialized logopedic treatment. A defect of the thumb is treated by transplanting a tendon and muscle or transferring the position of the index finger. In addition to surgery, in order to maximize a patient's benefit and to reduce functional insufficiency, complementary treatments such as rehabilitation and physiotherapy are recommended. In our study, we describe eight patients of different ages with various cases of Nager syndrome. The aim of our work was to present the actual genetic knowledge on this disease and its treatment procedures.
Topics: Child; Humans; Young Adult; Adult; Mandibulofacial Dysostosis; Cleft Palate; Micrognathism; Syndrome; RNA Splicing Factors
PubMed: 38254920
DOI: 10.3390/genes15010029 -
Journal of Oral Biosciences Mar 2024The purpose of this study was to perform morphological and immunohistochemical (IHC) analysis of the submandibular glands (SMGs) in early development in Apert syndrome...
OBJECTIVES
The purpose of this study was to perform morphological and immunohistochemical (IHC) analysis of the submandibular glands (SMGs) in early development in Apert syndrome model mice (Ap mice).
METHODS
ACTB-Cre homozygous mice were mated with fibroblast growth factor receptor 2 (Fgfr2) mice; ACTB-Cre heterozygous mice (ACTB-Cre mice) at embryonic day (E) 13.5 served as the control group, and Fgfr2 mice (Ap mice) served as the experimental group. Hematoxylin and eosin (H&E) staining was performed on SMGs; Total SMG area and epithelial area were determined, and the epithelial occupancy ratio was calculated. Immunostaining was performed to assess the localization of FGF signaling-related proteins. Next, bromodeoxyuridine (BrdU)-positive cells were evaluated to assess cell proliferation. Finally, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining was performed to assess apoptosis in SMGs.
RESULTS
The epithelial occupancy ratio was significantly higher in SMGs of Ap mice compared with that in SMGs of controls. FGF7 and bone morphogenetic protein 4 (BMP4) exhibited different localizations in SMGs of Ap mice compared with SMGs of controls. Cell proliferation was higher in SMGs of Ap mice compared with that of controls; however, apoptosis did not different significantly between the two groups.
CONCLUSION
Our results suggest that enhanced FGF signaling conferred by missense mutations in FGFR2 promotes branching morphogenesis in SMGs of Ap mice.
Topics: Animals; Mice; Acrocephalosyndactylia; Morphogenesis; Mutation; Receptor, Fibroblast Growth Factor, Type 2; Submandibular Gland
PubMed: 38246420
DOI: 10.1016/j.job.2024.01.001 -
BMC Pediatrics Jan 2024Radioulnar synostosis with amegakaryocytic thrombocytopenia (RUSAT) type 2, caused by MDS1 and EVI1 complex locus (MECOM) gene mutations, is a rare inherited bone marrow...
Radioulnar synostosis with amegakaryocytic thrombocytopenia (RUSAT) type 2, caused by MDS1 and EVI1 complex locus (MECOM) gene mutations, is a rare inherited bone marrow failure syndrome (IBMFS) with skeletal anomalies, characterized by varying presentation of congenital thrombocytopenia (progressing to pancytopenia), bilateral proximal radioulnar synostosis, and other skeletal abnormalities. Due to limited knowledge and heterogenous manifestations, clinical diagnosis of the disease is challenging. Here we reported a novel MECOM mutation in a Chinese boy with typical clinical features for RUSAT-2. Trio-based whole exome sequencing of buccal swab revealed a novel heterozygous missense mutation in exon 11 of the MECOM gene (chr3:168818673; NM_001105078.3:c.2285G > A). The results strongly suggest that the variant was a germline mutation and disease-causing mutation. The patient received matched unrelated donor hematopoetic stem cell transplantation (HSCT). This finding was not only expanded the pathogenic mutation spectrum of MECOM gene, but also provided key information for clinical diagnosis and treatment of RUSAT-2.
Topics: Humans; Male; China; MDS1 and EVI1 Complex Locus Protein; Mutation; Mutation, Missense; Radius; Synostosis; Thrombocytopenia; Transcription Factors; Ulna
PubMed: 38245683
DOI: 10.1186/s12887-024-04552-1 -
Life Science Alliance Apr 2024The X-linked form of Opitz BBB/G syndrome (OS) is a monogenic disorder in which symptoms are established early during embryonic development. OS is caused by pathogenic...
The X-linked form of Opitz BBB/G syndrome (OS) is a monogenic disorder in which symptoms are established early during embryonic development. OS is caused by pathogenic variants in the X-linked gene Disease-associated variants are distributed across the entire gene locus, except for the N-terminal really interesting new gene (RING) domain that encompasses the E3 ubiquitin ligase activity. By using genome-edited human induced pluripotent stem cell lines, we here show that absence of isoforms containing the RING domain of MID1 causes severe patterning defects in human brain organoids. We observed a prominent neurogenic deficit with a reduction in neural tissue and a concomitant increase in choroid plexus-like structures. Transcriptome analyses revealed a deregulation of patterning pathways very early on, even preceding neural induction. Notably, the observed phenotypes starkly contrast with those observed in MID1 full-knockout organoids, indicating the presence of a distinct mechanism that underlies the patterning defects. The severity and early onset of these phenotypes could potentially account for the absence of patients carrying pathogenic variants in exon 1 of the gene coding for the N-terminal RING domain.
Topics: Humans; Brain; Esophagus; Hypertelorism; Hypospadias; Induced Pluripotent Stem Cells; Microtubule Proteins; Nuclear Proteins; Transcription Factors; Ubiquitin-Protein Ligases
PubMed: 38238086
DOI: 10.26508/lsa.202302288 -
Scientific Reports Jan 2024Despite the undertaken treatment, children with nonsyndromic sagittal craniosynostosis (NSC) are burdened with problems with speech development, visuospatial and other...
Despite the undertaken treatment, children with nonsyndromic sagittal craniosynostosis (NSC) are burdened with problems with speech development, visuospatial and other cognitive deficits. The electroencephalographic assessment has not influenced the diagnostics and treatment strategy of craniosynostosis so far but the introduction of quantitative EEG (QEEG) protocols renewed an interest in the functional aspect of this disease. In this study we retrospectively assessed the QEEG records of 25 children with NSC aged 1-18 months (mean age 9.62 months) before and after surgery. In each case, the amplitude, interhemispheric (ICoh) and intrahemispheric (HCoh) coherence indices were calculated. Obtained data were compared to age-matched control group of 25 normocephalic children. Children with NSC presented significantly lower values of amplitudes and intrahemispheric coherence in occipital, posterior parietal and posterior temporal regions than normocephalic children. The values of amplitudes, ICoh and HCoh in pre- and postoperative QEEG records mostly remained unchanged, with a slight improvement in HCoh in centro-parietal area. These findings suggest that NSC children present their own QEEG profile. The operative treatment improves an intrahemispheric connectivity, but there still exists a significant difference in the occipitotemporal, frontotemporal and centro-frontal areas, which may be considered as a functional substrate of reported speech and neurocognitive problems. QEEG findings in nonsyndromic sagittal craniosynostosis.
Topics: Child; Humans; Infant; Retrospective Studies; Craniosynostoses; Electroencephalography; Temporal Lobe; Cognition Disorders
PubMed: 38221524
DOI: 10.1038/s41598-024-51858-2 -
Journal of AAPOS : the Official... Feb 2024To better characterize the correlation of bony orbital dysmorphology with strabismus in craniosynostosis.
PURPOSE
To better characterize the correlation of bony orbital dysmorphology with strabismus in craniosynostosis.
METHODS
The medical records of patients with craniosynostosis with and without strabismus seen at Rady Children's Hospital (San Diego, CA) from March 2020 to January 2022 were reviewed retrospectively in this masked, case-control study. Computed tomography scans of the orbits were analyzed to obtain dimensions of the orbital entrance and orbital cone. Primary outcome was correlation of strabismus with orbital measurements.
RESULTS
A total of 30 orbits from 15 patients with strabismus and 15 controls were included. Craniofacial disorders included in the study were nonsyndromic craniosynostosis (63%), Crouzon syndrome (13%), Apert syndrome (13%), and Pfeiffer syndrome (10%). Orbital index (height:width ratio) (P = 0.01) and medial orbital wall angle (P = 0.04) were found to differ significantly between the strabismus and control groups.
CONCLUSIONS
In our small cohort, bony orbital dimensions, including the ratio of orbital height to width and bowing of the medial orbital wall, were associated with strabismus in craniosynostosis.
Topics: Child; Humans; Case-Control Studies; Retrospective Studies; Craniosynostoses; Acrocephalosyndactylia; Strabismus; Orbit
PubMed: 38219920
DOI: 10.1016/j.jaapos.2023.10.006