X-linked retinoschisis: novel mutation in the initiation codon of the XLRS1 gene in a large family.

PURPOSE: To describe a novel point mutation in the initiation codon of the XLRS1 gene in a large family and the clinical features of males affected with X-linked juvenile retino-schisis. METHODS: Genealogic investigation and mutation screening of the XLRS1 gene were performed for a 4-generation family consisting of 72 members. Affected males were evaluated clinically between 1986 and 2004 with up to 18 years of follow-up. RESULTS: We identified a novel point mutation (1A>T transversion) in the initiation codon of the XLRS1 gene in affected males resulting in an amino acid substitution of methionine to leucine (Met1Leu), therefore abolishing the translation initiation Met codon. CONCLUSION: Identification of the disease-causing mutation in this family with long-term follow-up allows for earlier and more accurate identification of individuals at risk for this inherited progressive macular degeneration, provides for more accurate genetic counseling, and contributes to our understanding of the pathophysiology of this disorder.

Anesthesia monitoring by registered nurses during cataract surgery: assessment of need for intraoperative anesthesia consultation.

PURPOSE: To assess the frequency and risk factors for intraoperative anesthesia consultation when performing cataract surgery monitored by registered nurses. SETTING: Iowa City Veterans Affairs Medical Center, Iowa City, Iowa, USA. METHODS: This retrospective review was of 270 cataract surgeries performed under local anesthesia from April 1, 2002, to April 1, 2003. RESULTS: The American Society of Anesthesiologists (ASA) classification of each patient was determined: 1 patient was classified as ASA 1. One hundred fifty patients were classified as ASA 2. One hundred nineteen patients were classified as ASA 3. The anesthesiology department was consulted 24 times. Nineteen consultations involved patients who were ASA 3, and 5 consultations involved patients who were ASA 2 (P<.001). In most cases (23 of 24), the anesthesia service provided a consultation (eg, increase oxygen flow rate, clarification of electrocardiogram, start intravenous line, equipment repair) and left the nurses to continue to monitor the patient. In only 1 case (ASA 3), the anesthesia service converted the case to monitored anesthesia care and relieved the nurse to monitor the patient. CONCLUSIONS: In this study, monitoring of routine cataract surgery by registered nurses was associated with a low rate of intraoperative anesthesia consultation. Most consultations resulted in little intervention. The ASA classification appears predictive of the need for intraoperative anesthesia consultation.

Autosomal dominant pattern dystrophy: identification of a novel splice site mutation in the peripherin/RDS gene.

PURPOSE: To describe the clinical features of and identify the mutation responsible for an autosomal dominant pattern dystrophy occurring in a three-generation family. METHODS: Five affected family members underwent clinical examination and additional testing including intravenous fluorescein angiography where indicated. Mutation screening of the peripherin/RDS gene was performed. RESULTS: Visual acuity ranged from 20/20 to counting fingers. All patients who reported vision loss noted the onset after the age of 40 years. Predominantly perifoveal, discrete, retinal pigment epithelial changes were present in all patients. Two patients had extensive peripheral yellowish flecks, and one had an atrophic macular scar. Mutation screening of the complete peripherin/RDS coding sequence and exon/intron boundaries revealed a novel splice site mutation. CONCLUSION: A three-generation family with an autosomal dominant pattern dystrophy arising from a previously unreported splice site mutation in the RDS gene is described.

X-linked retinoschisis: a clinical and molecular genetic review.

X-linked retinoschisis is a leading cause of macular degeneration in male children. It is characterized by a high degree of clinical variability. Clinical features include a stellate foveal retinoschisis, with or without peripheral retinoschisis. The schisis occurs within the inner retina, primarily at the level of the nerve fiber layer. The disease-causing gene, X-linked retinoschisis 1, has recently been identified, and is expressed in photoreceptor and bipolar cells. This gene codes for retinoschisin, a secreted protein containing a discoidin domain which may be involved in cellular adhesion or cell-cell interactions. The identification of this gene allows for improved diagnosis and contributes to the understanding of this condition. Visual prognosis is variable, as X-linked retinoschisis exhibits a high degree of phenotypic variability. Although there is no treatment to halt the progressive maculopathy, clinical management is directed toward treatment of amblyopia and surgical correction of certain complications. X-linked retinoschisis is an important condition to study, both to improve the clinical management of this disorder, and to better understand retinal function and development. Herein, we review the clinical, histopathologic, and molecular genetic and treatment options of X-linked retinoschisis.

Autosomal dominant Stargardt-like macular dystrophy: identification of a new family with a mutation in the ELOVL4 gene.

PURPOSE: To describe the clinical features and identify the mutation responsible for an autosomal dominant macular degeneration occurring in a four-generation family. METHODS: Family members underwent clinical examination and genealogical characterization. Mutation screening of the ELOVL4 gene was performed. RESULTS: Patients reported visual loss occurring at a mean age of 20 years. Fundus examination revealed varying degrees of central macular atrophy with or without flecks in all affected individuals. DNA sequence analysis showed a 5-bp deletion in exon 6 of the ELOVL4 gene, confirming the diagnosis of autosomal dominant Stargardt-like macular dystrophy. Genealogical analysis showed that this family represents a new affected branch of a previously described 12-generation family (31 branches) with this disorder. CONCLUSIONS: We characterized a new branch of a family with autosomal dominant Stargardt-like macular dystrophy. Identification of the disease-causing gene allows for improved genetic counseling of affected individuals.

X-linked retinoschisis: report of a family with a rare deletion in the XLRS1 gene.

PURPOSE: To describe the clinical features and identify the disease causing mutation in a family with X-linked retinoschisis. DESIGN: Cohort study. METHODS: Genealogical investigation and mutation screening of the XLRS1 gene were performed in a four generation family of Icelandic ancestry. Three affected family members were evaluated clinically over a 29-year period. RESULTS: A rarely reported, four base pair deletion (375- 378 del AGAT) in exon 5 of the XLRS1 gene was found in all affected males. A high degree of intrafamilial variability was observed in the progression of the disorder over 29 years. CONCLUSIONS: Identification of the disease causing mutation in this family allows for the diagnosis of individuals at risk for this inherited macular degeneration. Furthermore, the long-term follow-up of subjects with identical mutations helps to better characterize the highly variable clinical course of this disorder.