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International Journal of Molecular... Apr 2020Colobomata, persistent optic fissures, frequently cause congenital blindness. Here, we focused on optic fissure fusion using in vivo time-lapse imaging in zebrafish. We...
Colobomata, persistent optic fissures, frequently cause congenital blindness. Here, we focused on optic fissure fusion using in vivo time-lapse imaging in zebrafish. We identified the fusion initiating cells, which we termed "pioneer cells." Based on morphology, localization, and downregulation of the neuroretinal (NR) precursor marker , these cells could be considered as retinal pigment epithelial (RPE) progenitors. Notably, pioneer cells regain expression and integrate into the NR after fusion, indicating that they do not belong to the pool of RPE progenitors, supported by the lack of RPE marker expression in pioneer cells. They establish the first cellular contact between the margins in the proximal fissure region and separate the hyaloid artery and vein. After initiation, the fusion site is progressing distally, increasing the distance between the hyaloid artery and vein. A timed BMP (Bone Morphogenetic Protein) induction, resulting in coloboma, did not alter the morphology of the fissure margins, but it did affect the expression of NR and RPE markers within the margins. In addition, it resulted in a persisting basal lamina and persisting remnants of periocular mesenchyme and hyaloid vasculature within the fissure, supporting the necessity of BMP antagonism within the fissure margins. The hampered fissure fusion had severe effects on the vasculature of the eye.
Topics: Animals; Animals, Genetically Modified; Basement Membrane; Blood Vessels; Bone Morphogenetic Proteins; Coloboma; Optic Disk; Retinal Pigment Epithelium; Time-Lapse Imaging; Zebrafish; Zebrafish Proteins
PubMed: 32316164
DOI: 10.3390/ijms21082760 -
Ultrasound in Obstetrics & Gynecology :... Nov 2012In this Review, we aim to provide up-to-date and evidence-based answers to common questions regarding the diagnosis and prognosis of prenatally detected agenesis of the... (Review)
Review
In this Review, we aim to provide up-to-date and evidence-based answers to common questions regarding the diagnosis and prognosis of prenatally detected agenesis of the corpus callosum (ACC). A systematic literature search was performed to identify all reports of ACC and reference lists of articles were identified. ACC involves partial or complete absence of the main commissural pathway that connects the two cerebral hemispheres, and can be isolated (with no other abnormalities) or complex (coexisting with other abnormalities). It is a rare finding and the prevalence is difficult to estimate because of selection bias in reported series. The corpus callosum (CC) can be assessed on ultrasound by direct visualization, but indirect features, such as ventriculomegaly, absence of the cavum septi pellucidi or widening of interhemispheric fissure, are often the reason for detection in a screening population. Careful imaging in a center with a high level of expertise is required to make a full assessment and to exclude coexisting abnormalities, which occur in about 46% of fetuses. When available, magnetic resonance imaging appears to be an important adjunct as it allows direct visualization. It can reduce false-positive rates on ultrasound and can confirm ACC, it can assess whether this is complete or partial and it can help in detecting coexisting brain abnormalities not seen on ultrasound. The overall rate of chromosomal abnormality in fetuses with ACC is 18%, but this high rate includes both isolated and complex ACC; more recent studies suggest that chromosomal abnormalities are rare in isolated cases. Nevertheless, postnatal follow-up studies suggest that about 15% of cases thought to be isolated prenatally were found to have associated abnormalities after birth. Neurodevelopmental outcome in isolated ACC was recently reported in a systematic review and suggested normal outcome in about 65-75% of cases. Findings need to be considered in light of the several limitations of existing studies, in terms of study design, selection bias, varying definitions and imaging protocols, ascertainment bias and lack of control groups. These uncertainties mean that antenatal counseling is difficult and further large prospective studies are needed.
Topics: Agenesis of Corpus Callosum; Counseling; Female; Humans; Pregnancy; Ultrasonography, Prenatal
PubMed: 23024003
DOI: 10.1002/uog.12315 -
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 the American Academy of... Sep 2020The best-studied examples of genetically defined developmental disorders, such as Down syndrome (trisomy 21) and velocardiofacial syndrome (del22q11), have been known...
The best-studied examples of genetically defined developmental disorders, such as Down syndrome (trisomy 21) and velocardiofacial syndrome (del22q11), have been known since before the genomic era and were initially recognized as distinct syndromes based on their own unique constellation of dysmorphic and multisystem features. For example, Down syndrome is characterized by the co-occurrence of several dysmorphic features, including a flattened facial profile, slanted palpebral fissures, protruding tongue, and transverse palmar crease, with accompanying hypotonia, cardiac issues, and developmental delay. None of these features in isolation is specific to Down syndrome, and all features are not present in all cases, but the co-occurrence of multiple features from this set is a specific and sensitive marker for the presence of trisomy 21. To what extent might similar principles apply to the patterning of cognitive and behavioral features across different neurogenetic syndromes?
Topics: Child; Down Syndrome; Humans; Intellectual Disability; Mental Health; Trisomy
PubMed: 32171632
DOI: 10.1016/j.jaac.2020.03.002 -
Developmental Biology Apr 2021The vertebrate eye anlage grows out of the brain and folds into bilayered optic cups. The eye is patterned along multiple axes, precisely controlled by genetic programs,...
The vertebrate eye anlage grows out of the brain and folds into bilayered optic cups. The eye is patterned along multiple axes, precisely controlled by genetic programs, to delineate neural retina, pigment epithelium, and optic stalk tissues. Pax genes encode developmental regulators of key morphogenetic events, with Pax2 being essential for interpreting inductive signals, including in the eye. PAX2 mutations cause ocular coloboma, when the ventral optic fissure fails to close. Previous studies established that Pax2 is necessary for fissure closure and to maintain the neural retina -- glial optic stalk boundary. Using a Pax2 knock-in allele we discovered that the mutant optic nerve head (ONH) lacks molecular boundaries with the retina and RPE, rendering the ONH larger than normal. This was preceded by ventronasal cup mispatterning, a burst of overproliferation and followed by optic cup apoptosis. Our findings support the hypothesis that ONH cells are tripotential, requiring Pax2 to remain committed to glial fates. This work extends current models of ocular development, contributes to broader understanding of tissue boundary formation and informs the underlying mechanisms of human coloboma.
Topics: Animals; Animals, Genetically Modified; Body Patterning; Cell Proliferation; Coloboma; Eye; Female; Gene Expression Regulation, Developmental; Gene Knock-In Techniques; Male; Mice; Mice, Inbred C57BL; Optic Disk; PAX2 Transcription Factor; Retina; Stem Cells
PubMed: 33428890
DOI: 10.1016/j.ydbio.2020.12.020 -
Romanian Journal of Morphology and... 2016A 46-year-old female patient presented with photosensitivity, symmetric arthritis, episodic plantar pain and strikingly redundant plantar skin folds, likely due to...
A 46-year-old female patient presented with photosensitivity, symmetric arthritis, episodic plantar pain and strikingly redundant plantar skin folds, likely due to lipoatrophy after recurrent episodes of plantar panniculitis. In this context, leukopenia with lymphopenia, thrombocytopenia and positive antinuclear antibodies were revelatory for systemic lupus erythematosus. However, a small cerebriform plantar collagenoma, along with discrete dysmorphic features with downslanting palpebral fissures and mild right ptosis, second and third syndactyly and a larger first right toe since childhood, and early-onset bilateral ovarian cystadenoma, suggested a minimal Proteus syndrome. Genetic confirmation could not be performed. As adipose tissue dysregulation may be a feature of Proteus syndrome, the possible mechanisms leading to localized lipoatrophy in this setting are discussed. This case enlights intriguing links between adipogenesis, inflammation and dysmorphology. From a practical point of view, finding and treating an over-imposed inflammation could help limit damage in a hamartomatous syndrome.
Topics: Female; Foot; Humans; Middle Aged; Proteus Syndrome; Skin Diseases
PubMed: 28002528
DOI: No ID Found -
Developmental Biology Aug 2018Defects in choroid fissure (CF) formation and closure lead to coloboma, a major cause of childhood blindness. Despite genetic advances, the cellular defects underlying...
Defects in choroid fissure (CF) formation and closure lead to coloboma, a major cause of childhood blindness. Despite genetic advances, the cellular defects underlying coloboma remain poorly elucidated due to our limited understanding of normal CF morphogenesis. We address this deficit by conducting high-resolution spatio-temporal analyses of CF formation and closure in the chick, mouse and fish. We show that a small ventral midline invagination initiates CF formation in the medial-proximal optic cup, subsequently extending it dorsally toward the lens, and proximally into the optic stalk. Unlike previously supposed, the optic disc does not form solely as a result of this invagination. Morphogenetic events that alter the shape of the proximal optic cup also direct clusters of outer layer and optic stalk cells to form dorsal optic disc. A cross-species comparison suggests that CF closure can be accomplished by breaking down basement membranes (BM) along the CF margins, and by establishing BM continuity along the dorsal and ventral surfaces of the CF. CF closure is subsequently accomplished via two distinct mechanisms: tissue fusion or the intercalation of various tissues into the inter-CF space. We identify several novel cell behaviors that underlie CF fusion, many of which involve remodeling of the retinal epithelium. In addition to BM disruption, these include NCAD downregulation along the SOX2 retinal CF margin, and the protrusion or movement of partially polarized retinal cells into the inter-CF space to mediate fusion. Proximally, the inter-CF space does not fuse or narrow and is instead loosely packed with migrating SOX2/PAX2/Vimentin astrocytes until it is closed by the outgoing optic nerve. Taken together, our results highlight distinct proximal-distal differences in CF morphogenesis and closure and establish detailed cellular models that can be utilized for understanding the genetic bases of coloboma.
Topics: Animals; Chick Embryo; Choroid; Coloboma; Eye; Mice; Morphogenesis; Optic Disk; Retina; Spatio-Temporal Analysis; Zebrafish
PubMed: 29803644
DOI: 10.1016/j.ydbio.2018.05.010 -
Cureus Aug 2022Ocular coloboma is a rare congenital anomaly that arises due to an abnormality in embryogenesis. It occurs due to failed fusion of the embryonic fissure resulting in a...
Ocular coloboma is a rare congenital anomaly that arises due to an abnormality in embryogenesis. It occurs due to failed fusion of the embryonic fissure resulting in a persistent defect. Colobomas may present with vision loss but are most commonly asymptomatic and diagnosed incidentally. In this article, we present a case of asymptomatic chorioretinal coloboma diagnosed on routine screening. The patient was managed with prophylactic argon laser retinopexy to prevent complications leading to visual impairment in the future.
PubMed: 36127994
DOI: 10.7759/cureus.28048 -
Medicina (Kaunas, Lithuania) Mar 2022Anal stenosis, which develops as a result of aggressive excisional hemorrhoidectomy, especially with the stoutly use of advanced technologies (LigaSure, ultrasonic... (Review)
Review
Anal stenosis, which develops as a result of aggressive excisional hemorrhoidectomy, especially with the stoutly use of advanced technologies (LigaSure, ultrasonic dissector, laser, etc.), has become common, causing significant deterioration in the patient's quality of life. Although non-surgical treatment is effective for mild anal stenosis, surgical reconstruction is unavoidable for moderate to severe anal stenosis that causes distressing, severe anal pain, and inability to defecate. The problem in anal stenosis, unlike anal fissure, is that the skin does not stretch as a result of chronic fibrosis due to surgery. Therefore, the application of lateral internal sphincterotomy does not provide satisfactory results in the treatment of anal stenosis. Surgical treatment methods are based on the use of flaps of different shapes and sizes to reconstruct the anal caliber and flexibility. This article aims to summarize most-used surgical techniques for anal stenosis regarding functional and surgical outcomes.
Topics: Anorectal Malformations; Constriction, Pathologic; Fissure in Ano; Hemorrhoids; Humans; Quality of Life
PubMed: 35334538
DOI: 10.3390/medicina58030362 -
Romanian Journal of Morphology and... 2007The Holt-Oram syndrome or atriodigital dysplasia is an autosomal dominant disorder with near complete penetrance and variable expression, caused by mutations of the TBX5...
The Holt-Oram syndrome or atriodigital dysplasia is an autosomal dominant disorder with near complete penetrance and variable expression, caused by mutations of the TBX5 gene (12q24.1), affecting one in 100 000 live births. 60% of cases are familial and 40% sporadic. We present the case of a 24 years old male patient with a personal history of bilateral coxa vara surgically corrected on the right at the age of 8 years, complicated by osteochondritis, short stature (160 cm), underweight (37 kg, BMI 14.45 kg/cm(2)), triangular face, micrognathia, down slanting palpebral fissures, hypertelorism, low set ears, scoliosis, narrow shoulders, shortened left arm, left thumb agenesia, limited supination, abnormal toes, hypoplastic muscles, atrial septal defect ostium secundum type, incomplete right bundle branch block, hypoacusia and normal intelligence.
Topics: Abnormalities, Multiple; Adult; Heart Defects, Congenital; Humans; Male; Mutation; Syndrome; T-Box Domain Proteins; Upper Extremity Deformities, Congenital
PubMed: 17502954
DOI: No ID Found