¡¡¡¡RESULTS

¡¡¡¡A total of 29 cases with DRS type I were evaluated. 55.17% of the patients were female, and 44.83% were male. Mean age was 9.48 years old. 10.3% of our patients had family history of strabismus. The left eye was more commonly affected (72.41%). Bilateral cases were 17.24%. Esodeviaª²tion was seen in 69.23% and exodeviation in 15.38% of the patients. Orthotropia was noted in 15.38%. The incidence of amblyopia was only 3.84%.

¡¡¡¡We studied 2 markers: D8S553 and D8S1797 on chromosome 8. Our studies did not support linkage between DRS and chromosome 8 with the noted markers in our patients.

¡¡¡¡DISCUSSION

¡¡¡¡There is general agreement that DRS has a more common occurrence in the left eye than in the right eye and also more common in females. Bilateral involvement is less common than unilateral occurrence[9]. In our patients left eye was more commonly (72.41%) affected than right eye. Bilateral cases were less common than unilateral cases (17.24%). It was more common in females than males. These finding is similar to large recent surveys[9].

¡¡¡¡Karyotypic abnormalities associated with different chromosoª²mes have been found in patients with DRS. The first reported localization of the gene responsible for DRS was a contiguous gene syndrome resulting from a de novo 8q12.2ª²q21.2 deletion characterized by branchioª²otoª²renal syndrome, DRS, hydrocephalus, and aplasia of the trapezius muscle[3]. The critical region for DRS has been narrowed to an interval of approximately 1cm between markers D8S553 and D8S1797[4].

¡¡¡¡An insertion/deletion event resulting in both the deletion of chromosome region 8q12ª²13 and the insertion of this segment into 6q25 was noted in a patient with DRS, mental retardation, and other anatomic malformations[5]. A de novo deletion of a region of chromosome 4 (4q27ª²31) has been reported in a 15ª²yearª²old boy with bilateral blepharoptosis, DRS, and mild learning difficulties[6].

¡¡¡¡Cytogenetic analysis of two siblings manifesting with DRS, bilateral sensorineural deafness, unilateral renal agenesis, and preauricular skin tags indicated the presence of a supernumerary bisatellited marker chromosome derived from chromosome 22pterª²q11[7]. Appukuttan and et al[8] described a large fourª²generation family with 25 living members affected with DRS transmitted in a fully penetrant autosomalª²dominant pattern and concluded strong evidence for linkage of an autosomalª²dominant from of DRS to 2q31.

¡¡¡¡Karyotypic abnormalities associated with chromosome 8 markers D8S553 and D8S1797 has been reported more than other chromosomes and markers[4], therefore we studied these two markers on chromosome 8.

¡¡¡¡In our study we didn't find any linkage between DRS and chromosome 8 with use of D8S553 and D8S1797 markers. The possible cause of this finding is that DRS in our patients was sporadic but in other reports was familial. We recommended study with more patients, other markers and other chromosomes.

¡¡¡¡¡¾²Î¿¼ÎÄÏס¿

¡¡¡¡1 Shauly Y, Weissman A, Meyer E. Ocular and systemic characteristics of Duane syndrome. J Pediatr Ophthalmol Strabismus1993;30 (3):178ª²183

¡¡¡¡2 Kirkham TH. Inheritance of Duane¬ðs syndrome. Br J Ophthalmol1970;54(5):323ª²329

¡¡¡¡3 Vincent C, Kalatzis V, Compain S, Levilliers J, Slim R, Graia F, Pereira ML, Nivelon A, Croquette MF, Lacombe D. A proposed new contiguous gene syndrome on 8q consists of Branchioª²Otoª²Renal (BOR) syndrome, Duane syndrome, a dominant form of hydrocephalus and trapeze aplasia; implications for the mapping of the BOR gene. Hum Mol
Genet1994;3(10):1859ª²1866

¡¡¡¡4 Rickard S, Parker M, van¬ðt Hoff W, Barnicoat A, Russellª²Eggitt I, Winter RM, Bitnerª²Glindzicz M. Otoª²faciocervical (OFC) syndrome is a contiguous gene deletion syndrome involving EYAI: molecular analysis confirms allelism with BOR syndrome and further narrows the Duane syndrome critical region to 1 cM. Hum Genet2001;108(5):398ª²403

¡¡¡¡5 Calabrese G, Stuppia L, Morizio E, Guanciali Franchi P, Pompetti F, Mingarelli R, Marsilio T, Rocchi M, Gallenga PE, Palka G, Dallapiccola B. Detection of an insertion deletion of region 8q13ª²q21.2 in a patient with Duane syndrome: implications for mapping and cloning a Duane gene. Eur J Hum Genet1998;6(3): 187ª²193

¡¡¡¡6 Chew CK, Foster P, Hurst JA, Salmon JF. Duane¬ðs retraction syndrome associated with chromosome 4q27ª²31 segment deletion. Am J Ophthalmol1995;119(6): 807ª²809

¡¡¡¡7 Cullen P, Rodgers C, Callen DF, Connolly VM, Eyre H, Fells P, Gordon H, Winter RM, Thakker RV. Association of familial Duane anomaly and urogenital abnormalities with a bisatellited marker derived from chromosome 22. Am J Med Genet1993;47(6):925ª²930

¡¡¡¡8 Appukuttan B, Gillanders E, Juo SH, Freasª²Lutz D, Ott S, Sood R, Van Auken A, Baileyª²Wilson J, Wang X, Patel RJ, Robbins CM, Chung M, Annett G, Weinberg K, Borchert MS, Trent JM, Brownstein MJ, Stout JT.Localization of a gene for Duane retraction syndrome to chromosome 2q31. Am J Hum Genet1999;65(6):1639ª²1646

¡¡¡¡9 DeRespinis PA, Caputo AR, Wagner RS, Guo S. Duane retraction syndrome. Surv Ophthalmol1993;38:257

ÉÏÒ»Ò³  [1] [2]