Retarded growth and deficits in the enteric and parasympathetic nervous system in mice lacking GFR alpha2, a functional neurturin receptor. (1/222)

Glial cell line-derived neurotrophic factor (GDNF) and a related protein, neurturin (NTN), require a GPI-linked coreceptor, either GFR alpha1 or GFR alpha2, for signaling via the transmembrane Ret tyrosine kinase. We show that mice lacking functional GFR alpha2 coreceptor (Gfra2-/-) are viable and fertile but have dry eyes and grow poorly after weaning, presumably due to malnutrition. While the sympathetic innervation appeared normal, the parasympathetic cholinergic innervation was almost absent in the lacrimal and salivary glands and severely reduced in the small bowel. Neurite outgrowth and trophic effects of NTN at low concentrations were lacking in Gfra2-/- trigeminal neurons in vitro, whereas responses to GDNF were similar between the genotypes. Thus, GFR alpha2 is a physiological NTN receptor, essential for the development of specific postganglionic parasympathetic neurons.  (+info)

Congenital myasthenia gravis: clinical and HLA studies in two brothers. (2/222)

Two brothers with congenital myasthenia gravis are described. In both, ptosis and ophthalmoplegia responded poorly to oral anticholinesterase therapy and to thymectomy. The brothers had two different HLA haplotypes and neither had the HLA-A1-B8-DW3 haplotypes which are commonly associated with myathenia gravis in adult-onset cases.  (+info)

Results following treatment of third cranial nerve palsy in children. (3/222)

PURPOSE: To investigate the etiology, sensory, motor, and cosmetic results of treatment for oculomotor (CNIII) palsy in children. METHODS: We conducted a retrospective review of the clinical records of children with a diagnosis of CNIII palsy who were followed up in our practice between 1981 and 1996. RESULTS: During the 15-year period, 49 children with 53 affected eyes were followed for a mean of 5.5 years. CNIII palsy was congenital in one third of cases and secondary to postnatal trauma in another third. Thirty-three of the eyes were affected before visual maturation (age 8 years) and 27 eyes developed amblyopia. None of the 6 eyes with amblyopia in which visual acuity could be quantitated had measurable improvement of Snellen acuity after treatment. Overall, visual acuity was between 6/5 and 6/12 at the last follow-up visit in 56% of affected eyes. Ocular alignment was greatly improved after recess-resect procedures on the horizontal rectus muscles, but binocular function was difficult to preserve or restore. Blepharoptosis improved after levator palpebrae muscle resection or eyelid suspension procedures. CONCLUSIONS: CNIII palsy may undergo partial resolution in children, but surgical treatment is frequently necessary. Although surgery can result in cosmetically acceptable alignment of the eyes, it rarely results in restoration or achievement of binocular function. Multiple procedures are often necessary to maintain good ocular alignment. Several surgical procedures may be needed to correct related blepharoptosis and maintain an acceptable eyelid position. Treatment of amblyopia is only effective in maintaining the level of visual acuity present at the onset of the CNIII palsy, and improvement in acuity is difficult to achieve.  (+info)

CFEOM3: a new extraocular congenital fibrosis syndrome that maps to 16q24.2-q24.3. (4/222)

PURPOSE: To define the clinical characteristics and determine the gene localization for a previously undescribed form of congenital fibrosis of the extraocular muscles (CFEOM), referred to as CFEOM type 3 (CFEOM3). METHODS: A large family with CFEOM was identified, and participating individuals underwent ophthalmologic examination and donated blood for genetic analysis. The family's disorder was tested for linkage to the known CFEOM loci, followed by a genome-wide search and linkage refinement using polymorphic DNA markers. RESULTS: Thirty-eight members of this Canadian family participated in the study. Affected individuals are born with a nonprogressive eye movement disorder characterized by variable expression of ptosis and restrictive external ophthalmoplegia. Severely affected individuals have ptosis, primary gaze fixed in a hypo- and exotropic position, and marked restriction of eye movement bilaterally. Mildly affected individuals have normally positioned globes with a limitation of vertical gaze. Moderately affected individuals have asymmetrical involvement with one eye severely and one eye mildly affected. The disorder is autosomal dominant with variable expression and probable incomplete penetrance. Genetic analysis reveals linkage to markers on 16q24.2q24.3. A maximum lod score of 5.8 occurs at markers D16S3063 and D16S689, and the CFEOM3 disease gene is located within a 5.6-cM region flanked by D16S486 and D16S671. CONCLUSIONS: These data establish that CFEOM3 is a phenotypically variant and genotypically distinct form of CFEOM with linkage to chromosome 16qter. The authors have previously demonstrated that CFEOM1 results from a developmental absence of the superior division of the oculomotor nerve. The authors hypothesize that CFEOM3 results from a defect analogous to, but distinct from CFEOM1.  (+info)

Extraocular muscle responses to high dose intravenous methylprednisolone in myasthenia gravis. (5/222)

Three patients with generalised myasthenia gravis and three with ocular myasthenia gravis received two to five courses of high dose intravenous methylprednisolone because of the failure of standard immunomodulating therapies. Changes in myasthenic signs were assessed using a four step system for grading muscle weakness and fatiguability in 10 test items. Although a brief and modest amelioration was found from day 1 to day 2 after the initial infusion in two patients with generalised myasthenia gravis, all three experienced a prolonged phase of worsening followed by improvement before the next course. Conversely, for two of the patients with ocular myasthenia gravis, a transient but dramatic improvement of ptosis and ocular immobility was noted from 90 minutes to 5 hours after initiating the first infusion, followed by mild or no exacerbation. This 3 hour improvement may be related not only to possible differences in the neuromuscular junction, but also to corticosteroids unmasking the central adaptation for the peripheral ocular muscle weakness by increasing the acetylcholine release.  (+info)

Fine mapping suggests that the goat Polled Intersex Syndrome and the human Blepharophimosis Ptosis Epicanthus Syndrome map to a 100-kb homologous region. (6/222)

To clone the goat Polled Intersex Syndrome (PIS) gene(s), a chromosome walk was performed from six entry points at 1q43. This enabled 91 BACs to be recovered from a recently constructed goat BAC library. Six BAC contigs of goat chromosome 1q43 (ICC1-ICC6) were thus constructed covering altogether 4.5 Mb. A total of 37 microsatellite sequences were isolated from this 4.5-Mb region (16 in this study), of which 33 were genotyped and mapped. ICC3 (1500 kb) was shown by genetic analysis to encompass the PIS locus in a approximately 400-kb interval without recombinants detected in the resource families (293 informative meioses). A strong linkage disequilibrium was detected among unrelated animals with the two central markers of the region, suggesting a probable location for PIS in approximately 100 kb. High-resolution comparative mapping with human data shows that this DNA segment is the homolog of the human region associated with Blepharophimosis Ptosis Epicanthus inversus Syndrome (BPES) gene located in 3q23. This finding suggests that homologous gene(s) could be responsible for the pathologies observed in humans and goats.  (+info)

A novel X-linked dominant condition: X-linked congenital isolated ptosis. (7/222)

We present a large family with a previously undescribed condition: X-linked dominant congenital bilateral isolated ptosis. Linkage analysis defined a critical region between Xq24 and Xq27.1, with a maximum single-point LOD score of 2.88 at DXS1047 and DXS984. Male and female family members are equally affected, providing an example of an X-linked, truly dominant condition.  (+info)

Reoperation in acquired involutional ptosis. (8/222)

Postoperative upper lid asymmetry is a common problem following ptosis surgery. Recently we performed multiple ptosis operative procedures to correct lid asymmetry in the management of a patient with bilateral acquired upper eyelid ptosis. The patient's eyelids were corrected successfully after five procedures. We retrospectively reviewed the treatment of this patient with unsatisfactory results. The medical literature was reviewed for further insight into the common problem of reoperation after ptosis surgery.  (+info)

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