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PubMed1983

Embryotoxicity of phomopsin in rats.

The effect of phomopsin, the mycotoxin of Phomopsis leptostromiformis responsible for lupinosis, was examined in pregnant rats and their embryos. A single injection of the rate of 0.025-0.4 mg/kg was administered on days 6, 8, 10, 12 or 14 of pregnancy or repeated injections at the daily rate of 0.03 or 0.09 mg/kg were given on days 6-10 or 11-15. Effects on embryonic development were examined on day 20. A single dose of 0.4 mg/kg or repeated doses of 0.09 mg/kg caused heavy embryonic mortality. Repeated doses of 0.03 mg/kg over days 6-10 caused a lower mortality. Foetuses that survived the higher dose rates were severely retarded in their growth and skeletal ossification was irregular. The incidence of other developmental defects was too low for phomopsin to be unequivocally implicated. The dose levels used induced lesions of lupinosis of varying severity in the dams. Toxicity for dams and embryos was greater when the total dose was administered over 5 days than after a single injection.

Animals↗
PubMed1994

A gene for Waardenburg syndrome type 2 maps close to the human homologue of the microphthalmia gene at chromosome 3p12-p14.1.

Waardenburg syndrome (WS), an autosomal dominant syndrome of hearing loss and pigmentary disturbances, comprises at least two separate conditions. WS type 1 is normally caused by mutations in PAX3 located at chromosome 2q35 and is distinguished clinically by minor facial malformations. We have now located a gene for WS type 2. Two families show linkage to a group of microsatellite markers located on chromosome 3p12-p14.1. D3S1261 gave a maximum lod score of 6.5 at zero recombination in one large Type 2 family. In a second, smaller family the adjacent marker D3S1210 gave a lod of 2.05 at zero recombination. Interestingly, the human homologue (MITF) of the mouse microphthalmia gene, a good candidate at the phenotypic level, has recently been mapped to 3p12.3-p14.4.

Animals↗
PubMed2003

Mutations in SOX2 cause anophthalmia.

A submicroscopic deletion containing SOX2 was identified at the 3q breakpoint in a child with t(3;11)(q26.3;p11.2) associated with bilateral anophthalmia. Subsequent SOX2 mutation analysis identified de novo truncating mutations of SOX2 in 4 of 35 (11%) individuals with anophthalmia. Both eyes were affected in all cases with an identified mutation.

Anophthalmos↗
PubMed1994

Waardenburg syndrome type 2 caused by mutations in the human microphthalmia (MITF) gene.

Waardenburg syndrome type 2 (WS2) is a dominantly inherited syndrome of hearing loss and pigmentary disturbances. We recently mapped a WS2 gene to chromosome 3p12.3-p14.1 and proposed as a candidate gene MITF, the human homologue of the mouse microphthalmia (mi) gene. This encodes a putative basic-helix-loop-helix-leucine zipper transcription factor expressed in adult skin and in embryonic retina, otic vesicle and hair follicles. Mice carrying mi mutations show reduced pigmentation of the eyes and coat, and with some alleles, microphthalmia, hearing loss, osteopetrosis and mast cell defects. Here we show that affected individuals in two WS2 families have mutations affecting splice sites in the MITF gene.

Amino Acid Sequence↗
PubMed1994

Molecular basis of mouse microphthalmia (mi) mutations helps explain their developmental and phenotypic consequences.

Mutations in the mouse microphthalmia (mi) gene affect the development of a number of cell types including melanocytes, osteoclasts and mast cells. Recently, mutations in the human mi gene (MITF) were found in patients with Waardenburg Syndrome type 2 (WS2), a dominantly inherited syndrome associated with hearing loss and pigmentary disturbances. We have characterized the molecular defects associated with eight murine mi mutations, which vary in both their mode of inheritance and in the cell types they affect. These molecular data, combined with the extensive body of genetic data accumulated for murine mi, shed light on the phenotypic and developmental consequences of mi mutations and offer a mouse model for WS2.

Alleles↗
PubMedDate not supplied

A very high density microsatellite map (1 STR/41 kb) of 1.7 Mb on Xp22 spanning the microphthalmia with linear skin defects (MLS) syndrome critical region.

Microphthalmia with linear skin defects (MLS) syndrome is an X-linked disorder presenting only in XX individuals. It is characterised by dysmorphic features such as microphthalmia, sclerocornea, and linear streaks of erythematous and hypoplastic skin restricted to the head and neck. Karyotype analyses have so far revealed a terminal deletion or translocation causing monosomy for the distal Xp region (Xp22.3) in all patients. We have used existing cosmid clones from the region to perform a saturation screen for AC-type microsatellites with the goal of facilitating analysis of five novel patients with features of MLS. Three of these cases had an Xp22.3 abnormality, while the other two showed some characteristic features of MLS but had apparently normal karyotypes. Forty-two novel microsatellite markers have now been developed from the 1.7 Mb cloned interval. Ninety-three percent of the novel markers exhibited allelic variation, representing an average of one polymorphic PCR-based marker (STR) every 41 kb.

Contig Mapping↗
PubMed2004

Physical and transcript map of the autosomal dominant colobomatous microphthalmia locus on chromosome 15q12-q15 and refinement to a 4.4 Mb region.

Congenital microphthalmia is a developmental disorder characterized by shortened axial length of the eye. We have previously mapped the gene responsible for autosomal dominant colobomatous microphthalmia in a 5-generation family to chromosome 15q12-q15. Here, we set up a physical and transcript map of the 13.8 cM critical region, flanked by loci D15S1002 and D15S1040. Physical mapping and genetic linkage analysis using 20 novel polymorphic markers allowed the refinement of the disease locus to two intervals in close vicinity, namely a centromeric interval, bounded by microsatellite DNA markers m3-m17, and a telomeric interval, m76-m24, encompassing respectively 1.9 and 2.5 Mb. Moreover, we excluded three candidate genes, CKTSF1B1, KLF13 and CX36. Finally, although a phenomenon of anticipation was suggested by phenotypic and pedigree data, no abnormal expansion of three trinucleotide repeats mapping to the refine interval was found in affected individuals.

Cell Cycle Proteins↗
PubMed2005

Novel mutations in BCOR in three patients with oculo-facio-cardio-dental syndrome, but none in Lenz microphthalmia syndrome.

Oculo-facio-cardio-dental (OFCD) syndrome is a rare X-linked dominant condition with male lethality characterized by microphthalmia, congenital cataracts, facial dysmorphic features, congenital heart defects, and dental anomalies. Mutations in BCOR (BCL6 co-repressor) located in Xp11.4 have been described to cause OFCD syndrome. Lenz microphthalmia syndrome is inherited in an X-linked recessive pattern comprising microphthalmia/anophthalmia, mental retardation, malformed ears, digital, skeletal, and urogenital anomalies (synonym: microphthalmia with associated anomalies (MAA)). One locus for MAA has been mapped to Xq27-q28. Nonetheless, linkage and subsequent mutation analysis revealed a single missense mutation (p.P85L) in BCOR in a large family with presumed Lenz microphthalmia syndrome (MAA2). We describe novel mutations in BCOR in three patients with OFCD syndrome, two small deletions (c.2488_2489delAG and c.3286delG) and a submicroscopic deletion of about 60 kb encompassing at least BCOR exons 2-15. No BCOR mutation was detected in eight patients with Lenz microphthalmia syndrome. Our data confirm that BCOR is the causative gene for OFCD syndrome; however, the failure to identify any mutation in patients with Lenz microphthalmia syndrome together with the oligosymptomatic phenotype in the reported MAA2 patients suggest that BCOR is not the major gene for this syndrome.

Abnormalities, Multiple↗
PubMed2006

A two base pair deletion in the PQBP1 gene is associated with microphthalmia, microcephaly, and mental retardation.

X-linked mental retardation has been traditionally divided into syndromic (S-XLMR) and non-syndromic forms (NS-XLMR), although the borderlines between these phenotypes begin to vanish and mutations in a single gene, for example PQBP1, can cause S-XLMR as well as NS-XLMR. Here, we report two maternal cousins with an apparently X-linked phenotype of mental retardation (MR), microphthalmia, choroid coloboma, microcephaly, renal hypoplasia, and spastic paraplegia. By multipoint linkage analysis with markers spanning the entire X-chromosome we mapped the disease locus to a 28-Mb interval between Xp11.4 and Xq12, including the BCOR gene. A missense mutation in BCOR was described in a family with Lenz microphthalmia syndrome, a phenotype showing substantial overlapping features with that described in the two cousins. However, no mutation in the BCOR gene was found in both patients. Subsequent mutation analysis of PQBP1, located within the delineated linkage interval in Xp11.23, revealed a 2-bp deletion, c.461_462delAG, that cosegregated with the disease. Notably, the same mutation is associated with the Hamel cerebropalatocardiac syndrome, another form of S-XLMR. Haplotype analysis suggests a germline mosaicism of the 2-bp deletion in the maternal grandmother of both affected individuals. In summary, our findings demonstrate for the first time that mutations in PQBP1 are associated with an S-XLMR phenotype including microphthalmia, thereby further extending the clinical spectrum of phenotypes associated with PQBP1 mutations.

Abnormalities, Multiple↗
PubMed2004

Retinoblastoma, microphthalmia and the chromosome 13q deletion syndrome.

A 10-month-old boy, known to have the 13q deletion syndrome, presented with leukocoria in a microphthalmic right eye. He was found to have bilateral retinoblastoma requiring enucleation of the right eye and laser, cryotherapy and external beam radiation to the left eye. This case demonstrates that retinoblastoma may be present in a microphthalmic eye and that more than one imaging modality should be used in the evaluation of suspected retinoblastoma, as calcification may be absent on the computed tomography scan but present on B-mode ultrasound. Children with a known 13q deletion require immediate and serial ophthalmological examinations.

Chromosome Deletion↗
PubMedDate not supplied

Xp22.3 microdeletion in a 19-year-old girl with clinical features of MLS syndrome.

We describe a 19-year-old girl who has clinical features of microphthalmia with linear skin defects (MLS) syndrome caused by a microdeletion of Xp22.3. In addition to the classical ocular abnormalities and linear skin defects she has other features not previously described. She was previously reported in this journal in 1990 as poikiloderma congenitale, but her true diagnosis of an Xp22.3 microdeletion was clarified when fluorescent in situ hybridization (FISH) analysis indicated that one of her X chromosomes had a microdeletion including the KAL gene. We describe this patient with an Xp22.3 microdeletion to heighten awareness among dermatologists of this syndrome and to underscore the difficulties in diagnosing MLS syndrome.

Abnormalities, Multiple↗
PubMed2002

Complete elimination of incessant polymorphic ventricular tachycardia in an infant with MIDAS syndrome: use of endocardial mapping and radiofrequency catheter ablation.

Experience with radiofrequency catheter ablation of ventricular tachycardia (VT) in pediatric patients is limited. A 5-month-old white female infant (body weight 5.5 kg) with MIDAS syndrome who suffered from incessant polymorphic VT (ventricular rates 250 to 300 beats/min) and was unresponsive to medical treatment resulting in significantly depressed left ventricular (LV) function underwent a total of four catheter ablation procedures during a 5-month period. Each of the procedures reduced the number of morphologies and the rate of the tachycardia, but VT returned after each of the first three procedures, despite concomitant medical therapy. Activation mapping and pace mapping were used to identify the anatomic substrates, which were found at different locations at the LV septum and LV free wall. All forms of VT finally were ablated successfully. There were no significant complications. After the fourth procedure, the patient was in continuous sinus rhythm. Follow-up examination 29 months after the last procedure while the child was not taking any medication showed normal sinus rhythm and normal LV function. This report demonstrates the usefulness and safety of radiofrequency catheter ablation in an infant with polymorphic VT who was unresponsive to medical therapy.

Abnormalities, Multiple↗
PubMed2003

Morphology and morphogenesis of hereditary microphthalmia in Texel sheep.

The study presents a morphological description of inherited microphthalmia in Texel sheep and the morphogenesis of the lesion during embryonal development. The eyes of 28 newborn and young lambs with microphthalmia were examined morphologically. Blind rams with microphthalmia were crossed with ewes known to be carriers of the "microphthalmia factor", to obtain embryos of different age with and without microphthalmia for morphogenesis studies. The microphthalmic eyes showed an anteriorly located conus-shaped mass composed of connective tissue with cartilage, smooth muscle and fat tissue, particularly in the posterior part of the conus, and often islets of lacrimal glands and cystic structures lined with squamous epithelium in the anterior part. The iris, ciliary body and ciliary processes were incorporated in the periphery of the broad base of the conus. The conus was covered by a detached and folded but normally developed retina. The morphogenetic study showed an abnormal development of the lens vesicle. In embryos aged 24 days, the lens consisted of a solid unorganized proliferation of epithelial cells without formation of a lens capsule. An extensive overgrowth of primitive mesenchymal tissue followed, with infiltration and disintegration of the lens. In a later stage (45 days) a conus-shaped mass was seen in the anterior part of the eyes, which at 56 days consisted of mesenchymal tissue with focal differentiation to cartilage and epithelial structures in the anterior part of the conus. The primary event proved to be abnormal development of the lens vesicle, with disintegration of the lens and subsequent overgrowth of mesenchymal tissue. The mesenchymal tissue later differentiated in various directions, whereas the epithelial structures found in the microphthalmic eyes at days 56 and 132 and in the newborn lambs seemed to be remnants of the epithelial lens vesicle.

Animals↗
PubMed2002

First experience with a public domain computer-aided surgical system.

The outcome of complex craniofacial operations is critically dependent on careful and accurate preoperative planning. Recent advances in computer technology enable the surgeon to do surgical simulations directly on to a computer terminal. We describe the clinical application of a public domain-based computer-aided system in craniofacial surgery. Operation planning was based on clinical investigations and radiological images, with particular use of a virtual three-dimensional surgical simulation. Three patients with complex craniofacial malformations were admitted for orbital correction. Surgical simulation defined numerically the extent of bone movements and the extent of resection areas. Operations were guided by the virtual planning. The outcome was compared with the planning to assess the accuracy of the operative correction. Our first experience confirms that computer-assisted simulation is a reliable and useful tool that improves surgical planning and helps to evaluate the surgical outcome.

Adult↗
PubMed2000

[Cataract surgery in 79 patients with relative anterior microphthalmus (RAM): a review of anatomy, associated pathology and complications].

BACKGROUND: Naumann has coined the term relative anterior microphthalmus (RAM) for eyes with a dysproportional small anterior segment but no further malformation. Those eyes are characterized by corneal diameters of < 11 mm and total axial length of > 20 mm. PATIENTS AND METHODS: To evaluate and define morphometrical data and risk factors for cataract surgery in patients with relative anterior microphthalmus (RAM) 112 cataract operations of 79 patients with RAM were analysed. Associated ocular pathology (such as glaucoma, previous surgical interventions, etc.) and complications of cataract surgery were recorded. RESULTS: Average corneal diameter was 10.7 +/- 0.34 mm, AC-depth was 2.20 +/- 0.49 and average lens thickness 5.05 +/- 0.45 mm. Fifty five percent of the patient revealed myopic refraction. There was a high incidence of glaucoma (77%), cornea guttata (46.6%) and Pseudoexfoliation syndrome (16%) in the RAM-group. Sixty percent of patients previously underwent glaucoma surgery. After cataract surgery 51.2% of patients achieved a visual acuity of > 0.5; 69.8% > 0.4. The IOP was preoperatively 16.5 +/- 5.8 mm Hg (with 1.3 +/- 1.4 antiglaucomatous drugs). Postoperatively IOP dropped significantly to 13.6 +/- 3.2 mm Hg (with significant reduction of treatment (0.6 +/- 1.0) (p < 0.01). The anterior chamber depth deepened from 2.42 +/- 0.47 mm to 3.33 +/- 0.72 mm. CONCLUSIONS: The special anatomical situation in RAM is responsible for the high incidence of glaucoma and postoperative complications after cataract surgery. Cataract surgery helps not only to restore vision but also facilitates handling and regulation of intraocular pressure.

Aged↗
PubMed2002

Twins with oesophageal atresia and the CHARGE association.

Twins are rarely concordant for oesophageal atresia and tracheo-oesophageal fistula. Such a case is presented and their similar associated anomalies described. The CHARGE association is considered as a possible diagnosis and the aetiological implications considered.

Abnormalities, Multiple↗
PubMed2004

[Angle closure glaucoma in association with relative anterior microphthalmus (RAM) after premature birth-retinopathy (ROP)].

BACKGROUND: The infantile angle-closure glaucoma is a common and well characterized complication of retinopathy of prematurity (ROP). Progressive shallowing of the anterior chamber by retrolental fibrous masses is mostly responsible for the pressure elevation during the first years of life. Apart of this pathogenesis, ROP-associated glaucoma is totally different in cases that do not manifest until adulthood. Only few cases are described in the literature. CASE REPORT: A 36-year-old female patient presented with symptoms of acute intraocular pressure (IOP) elevation and fundus results of a cicatricial ROP stadium II. Control of IOP was not achieved by systemic and topical drug treatment. The biometry showed a relative anterior microphthalmus (RAM) in myopia. After peripheral iridectomy, the IOP normalized and remained stable over a long-time period. CONCLUSION: Myopia induction after ROP and ROP treatment often lead to special anatomical conditions corresponding to the classical relative anterior microphthalmus. Shallowing of the anterior chamber and development of angle-closure glaucoma increase with age. Thus, a manifestation not before the third decade of life was a typical finding in the literature review. A detailed recording of history and consideration of the biometric data are of importance for diagnosis. Peripheral iridectomy was found to be the therapy with the highest success rate. The increase of a pupillary block mechanism can prevent further visual loss to the often pre-damaged eyes. Consideration of this entity is crucial in unilateral IOP elevation, because an increasing prevalence of these patients can be expected due to the increase of premature babies since 1970.

Adult↗