Inheritance of Duane's syndrome

Pseudo-Duane retraction syndrome after orbital myositis

Orbital myositis is a rare, commonly idiopathic, inflammatory condition that affects one or more extraocular muscles. We present a case of unilateral orbital myositis affecting the lateral rectus muscle presenting with gaze-evoked amaurosis, pain, and diplopia, with restrictive limitation of adduction. With improvement in adduction after initiating treatment, we noted narrowing of the palpebral fissure on attempted adduction, mimicking Duane retraction syndrome (DRS). Reported cases of "pseudo-DRS" are associated with multiple etiologies and are characterized by retraction on attempted abduction rather than adduction, as occurs in true DRS. In this case, pseudo-DRS occurred in the setting of idiopathic orbital inflammatory syndrome (orbital myositis) with a motility pattern more consistent with true DRS.

Duane Retraction Syndrome: Clinical Features and a Case Group-Specific Surgical Approach

PURPOSE

To describe the clinical features of patients with Duane retraction syndrome (DRS) and evaluate the outcomes of surgical approaches based on the characteristics of each patient.

METHODS

The records of 38 Caucasian subjects with DRS were retrospectively reviewed. The patients were classified as type I, II, or III based on the Huber Classification. Ten patients underwent unilateral medial rectus (MR) recession due to abnormal head posture (AHP) and/or esotropia. Four patients underwent Y-splitting and recession of the lateral rectus (LR) with MR recession due to AHP and/or esotropia, upshoot, and globe retraction.

RESULTS

There was a preponderance of unilaterality, female gender, left eye, type I, orthotropia, upshoot, and low refractive error. All patients demonstrated globe retraction and fissure narrowing. AHP was only present in unilateral cases. Nine patients had amblyopia. More than half of the patients over 5 years of age had decreased stereopsis. MR recession decreased AHP to less than 8° in all patients. Y-splitting and recession of the LR eliminated upshoot in all four patients. One patient who underwent an 8-mm MR recession demonstrated -2 adduction limitation.

CONCLUSIONS

The DRS patients in our study demonstrated features that are consistent with previous reports in the literature. This study emphasizes the need to consider disease classification in the surgical management of DRS patients.

CHN1 gene mutation analysis in patients with Duane retraction syndrome

PURPOSE

To investigate CHN1 (chimerin 1) gene mutations in patients with isolated nonsyndromic Duane syndrome and accompanying positive familial history, bilaterality, or various systemic disorders.

METHODS

Patients with Duane retraction syndrome (DRS) and a positive family history of congenital ocular motility disturbance or bilateral involvement or accompanying any congenital disorder(s) seen consecutively at a single center from 2013 to 2016 were enrolled. All subjects underwent full ophthalmologic examination, including refraction, best-corrected visual acuity, ocular alignment and motility, globe retraction, and biomicroscopic or fundus evaluation. DNA samples were investigated by direct sequencing of the coding regions of the CHN1 gene.

RESULTS

A total of 30 patients (15 males) were included (mean age, 11.8 ± 10.4 years; range, 2-45 years): 8 cases presented with bilateral DRS; 22, with unilateral DRS. Family history of ocular motility abnormality was positive in 16 patients. Eleven cases had an additional congenital disorder. In 2 patients, 2 different mutations were detected in the CHN1 gene: p.E313K (c.937G>A) and p.N224S (c.671A>G).

CONCLUSIONS

CHN1 mutations were identified in 2 bilateral cases and in 1 parent of 1 affected case. One mutation is novel and occurred with additional vertical gaze abnormalities. Additional genetic studies evaluating chimerin 1 (CHN1) and its role in the development of the ocular motor axis are needed to provide new data about these mutations and phenotypic variations.

Duane retraction syndrome: causes, effects and management strategies

Duane retraction syndrome (DRS) is a congenital eye movement anomaly characterized by variable horizontal duction deficits, with narrowing of the palpebral fissure and globe retraction on attempted adduction, occasionally accompanied by upshoot or down-shoot. The etiopathogenesis of this condition can be explained by a spectrum of mechanical, innervational, neurologic and genetic abnormalities occurring independently or which influence each other giving rise to patterns of clinical presentations along with a complex set of ocular and systemic anomalies. Huber type I DRS is the most common form of DRS with an earlier presentation, while Huber type II is the least common presentation. Usually, patients with unilateral type I Duane syndrome have esotropia more frequently than exotropia, those with type II have exotropia and those with type III have esotropia and exotropia occurring equally common. Cases of bilateral DRS may have variable presentation depending upon the type of presentation in each eye. As regards its management, DRS classification based on primary position deviation as esotropic, exotropic or orthotropic is more relevant than Huber’s classification before planning surgery. Surgical approach to these patients is challenging and must be individualized based on the amount of ocular deviation, abnormal head position, associated globe retraction and overshoots.

Audiologic and otologic phenotype in children with Duane's Retraction Syndrome: A rare ophthalmologic disorder

OBJECTIVE

The focus of this study was to evaluate the prevalence, type, and severity of hearing impairment in patients with Duane's Retraction Syndrome and to relate these measures to patient demographics and other otologic and audiologic factors.

STUDY DESIGN

Retrospective AudGen Database analysis

SETTING

Tertiary academic referral center

PATIENTS

Pediatric patients in AudGenDB with a diagnosis of Duane's Retraction Syndrome (DRS).

INTERVENTIONS

Appropriate audiologic, otologic, and demographic data were recorded.

MAIN OUTCOME MEASURE

Seventy-nine patients (n = 79) met inclusion criteria. The first encounter with available audiometric data or the first encounter with hearing loss were documented. Audiograms were stratified by type and severity of hearing loss, and common associated medical issues were documented.

RESULTS

57 children had normal hearing; 22 had hearing loss. 9 ears had pure conductive hearing loss, 1 had pure sensorineural, 14 ears had components of both, and 79 had hearing loss that could not be specified. Multivariate regression revealed episodes of chronic otitis and craniofacial anomalies are associated with worse hearing loss.

CONCLUSION

This study presents a detailed characterization of hearing loss in patients with Duane's retraction syndrome. Conductive and sensorineural hearing loss are both prevalent among these children. Careful and early audiologic evaluation of all patients with DRS is important.

Wildervanck syndrome with hypoplastic frontal sinus: A rare case presentation

We report a case of Wildervanck syndrome exhibiting Klippel-Feil anomaly, Duane's retraction syndrome and congenital deafness. Since the first case was reported in 1952, there have been more reports describing this triad either complete or incomplete. Our case has a complete triad of the syndrome along with frontal sinus hypoplasia. Our case is unique as the triad was associated with frontal sinus hypoplasia, which is very rare association.

Diversified clinical presentations associated with a novel sal-like 4 gene mutation in a Chinese pedigree with Duane retraction syndrome

PURPOSE

To determine the underlying genetic cause of Duane retraction syndrome (DRS) in a non-consanguineous Chinese Han family.

METHODS

Detailed ophthalmic and physical examinations were performed on all members from a pedigree with DRS. All exons and their adjacent splicing junctions of the sal-like 4 (SALL4) gene were amplified with polymerase chain reaction and analyzed with direct sequencing in all the recruited family members and 200 unrelated control subjects.

RESULTS

Clinical examination revealed a broad spectrum of phenotypes in the DRS family. Mutation analysis of SALL4 identified a novel heterozygous duplication mutation, c.1919dupT, which was completely cosegregated with the disease in the family and absent in controls. This mutation was predicted to cause a frameshift, introducing a premature stop codon, when translated, resulting in a truncated SALL4 protein, i.e., p.Met640IlefsX25. Bioinformatics analysis showed that the affected region of SALL4 shared a highly conserved sequence across different species. Diversified clinical manifestations were observed in the c.1919dupT carriers of the family.

CONCLUSIONS

We identified a novel truncating mutation in the SALL4 gene that leads to diversified clinical features of DRS in a Chinese family. This mutation is predicted to result in a truncated SALL4 protein affecting two functional domains and cause disease development due to haploinsufficiency through nonsense-mediated mRNA decay.

Two novel CHN1 mutations in 2 families with Duane retraction syndrome

OBJECTIVE

To determine the genetic cause of Duane retraction syndrome (DRS) in 2 families segregating DRS as a dominant trait.

METHODS

Members of 2 unrelated pedigrees were enrolled in a genetic study. Linkage analysis was performed on the CHN1 locus. Probands and family members were screened for CHN1 mutations.

RESULTS

The 6 affected individuals in the 2 pedigrees have DRS. Both pedigrees are consistent with linkage to the locus. Sequence analysis revealed 2 novel heterozygous missense CHN1 mutations, c.422C>T and c.754C>T, predicted to result in α2-chimaerin amino acid substitutions P141L and P252S, respectively.

CONCLUSIONS

Genetic analysis of 2 pedigrees revealed 2 novel DRS mutations, bringing the number of DRS pedigrees known to harbor CHN1 from 7 to 9. Both mutations alter residues that participate in intramolecular interactions that stabilize the inactive, closed conformation of α2-chimaerin and, thus, are predicted to result in its hyperactivation. Moreover, amino acid residue P252 was previously reported to be altered to a different residue in a previously reported DRS pedigree; thus, this is the first report of 2 CHN1 mutations altering the same residue, further supporting a gain-of-function etiology.

CLINICAL RELEVANCE

Members of families segregating DRS as an autosomal dominant trait should be screened for mutations in the CHN1 gene, enhancing genetic counseling and permitting earlier diagnosis.

Analysis of the SALL4 gene in patients with Duane retraction syndrome in a South Indian population

Duane retraction syndrome (DRS) is a congenital eye movement disorder characterized most typically by partial or complete failure of abduction and narrowing of palpebral fissure with globe retraction on adduction. Recently mutations of the SALL4 gene on chromosome 20 have been linked to DRS associated with radial forearm malformations (Okihiro syndrome). In this prospective, non-interventional study we screened for SALL4 mutations in 72 patients clinically diagnosed as having isolated DRS or DRS associated syndromes. All four exonic and the neighboring intronic regions of SALL4 gene were amplified by sixteen sets of primers using polymerase chain reaction and were subjected to bi-directional sequencing and BLAST analysis. No genetic variations were detected in the coding region and in the neighboring intronic regions of the SALL4 gene suggesting an alternative mechanism in the pathogenesis of these disorders in the South Indian population.

Duane syndrome in the setting of chromosomal duplications

PURPOSE

To describe the clinical findings in 3 patients with Duane syndrome and 3 different chromosomal duplications that may indicate the location of genes involved in the pathogenesis of this ocular motility disorder.

DESIGN

Observational case series.

METHODS

setting: Clinical practice. patient or study population: Three patients with Duane syndrome and chromosomal duplications from the clinical practice of 1 of the authors. observation procedures: Chart review and retrieval of clinical data and results of pertinent clinical tests, in this case chromosomal studies. main outcome measure: Reporting of details of clinical findings and duplicated chromosomal regions.

RESULTS

Two patients had unilateral type I Duane syndrome and 1 had bilateral type I Duane syndrome. Two had cognitive delay, and all 3 had other systemic abnormalities, including a variety of congenital malformations. The chromosomal abnormalities that were detected using microarray analysis were 2q13(RP11-20G1,RP11-461N11) × 3, 10q24.2q26.3(101,532,585-135,284, 169) × 3, 20q13.12(44,796,613-44,945, 818) × 3, and 22q11.1q11.22(RP11-701M12, RP11-71G19) × 3.

CONCLUSIONS

Patients with Duane syndrome and associated congenital malformations or developmental delay should be evaluated for the presence of underlying chromosomal duplications. The regions of chromosomes 2, 10, and 22 that we report may harbor genes involved in the pathogenesis of Duane syndrome.

Review of the major findings about Duane retraction syndrome (DRS) leading to an updated form of classification

In view of all the reported evidence by electromyography in the 1970s, by histology in the 1980s, and by cerebral imagery since the 2000s, Duane retraction syndrome (DRS) has been described as the consequence of a congenital anomaly of the 6th cranial nerve nuclei with aberrant innervations by supply from the 3rd cranial nerve. Both genetic and environmental factors are likely to play a role when the cranial nerves and ocular muscles are developing between the 4th and the 8th week of gestation. New data from eye movement recordings contributed to better understanding the binocular control of saccades. Modeling of saccades in DRS seems promising for the quantification of the innervational deficit and the mechanical properties of the eye plant. The usual clinical classification of DRS needs to be updated in order to match more accurately the underlying dysinnervation of the extra ocular muscles and to illustrate the continuum that exists between the various forms. This review aims to summarize the major findings about DRS and to guide the clinician in the surgical management of this particular form of strabismus.

Thalidomide and misoprostol: Ophthalmologic manifestations and associations both expected and unexpected

Thalidomide is a very potent teratogen capable of causing severe systemic malformations if the fetus is exposed during the sensitive period. Although structural anomalies of the eye can occur from thalidomide exposure, the most frequent eye complication is secondary to damage to the cranial nuclei in the brain stem, resulting in aberrant neurologic connections causing a condition of abnormal ocular movement, Duane syndrome. A less frequent anomalous neurologic complication is tearing when eating (paradoxical gustolacrimal tearing or "crocodile tears") or lack of emotional tearing. The involvement of the 6th and 7th cranial nerves, often seen together in the thalidomide-affected individual, is also characteristic of Möbius syndrome/sequence. This syndrome usually occurs sporadically, but characteristic findings of this condition have also been observed in South American children who were born after an unsuccessful attempt to induce abortion with the prostaglandin drug misoprostol (Cytotec). Aberrant tearing also occurs in some individuals with Möbius syndrome. Autism spectrum disorder (ASD), an unexpected associated finding in a Swedish thalidomide study, is now also noted in Möbius studies, in patients both with and without exposure to misoprostol.

Left-sided Duane's Syndrome and Retinal Coloboma associated with Contralateral Microphthalmia

Case report of a 15-year-old girl presenting with a left-sided Duane's retraction syndrome (DURS) in combination with ipsilateral retinal coloboma and contralateral microphthalmia. Abduction limitation as well as narrowing of the palpebral fissure and globe retraction during attempted adduction (type I DURS) was demonstrated in the left eye. Additionally, a retinal coloboma was observed in the nasal inferior quadrant of the left eye. No other somatic or developmental abnormalities were observed and karyotypic analysis was normal. This is the first case of non-syndromic unilateral DURS associated with a contralateral major ocular malformation. This unusual clinical combination probably arose from the embryonic action of an eye-specific disruptor.

Clinical features associated with an I126M alpha2-chimaerin mutation in a family with autosomal-dominant Duane retraction syndrome

PURPOSE

We describe the clinical phenotype of a Mexican family segregating Duane syndrome as an autosomal-dominant trait linked to chromosome 2q31 (DURS2) and previously reported to harbor a heterozygous alpha2-chimaerin missense mutation.

METHODS

A 5-generation Mexican family was analyzed. Ten affected subjects were available for clinical examination. Participating subjects were tested for visual acuity, ocular alignment by prism cover testing, ocular ductions and versions, and globe retraction. In children, alignment was measured with the Krimsky test in cardinal positions of gaze.

RESULTS

Ten cases were included, 6 female and 4 male subjects. Five cases presented with bilateral and 5 with unilateral Duane syndrome. The right side was the most commonly affected side on unilateral cases. Five cases exhibited exotropia, 4 esotropia, and 1 hypotropia. Seven patients had severe limitation of abduction and two had moderate limitation. Four patients had mild adduction limitation and 4 had moderate limitation. No additional anomalies such as fourth (trochlear) nerve palsy, blepharoptosis, or dense amblyopia, which have been reported in previous families with Duane syndrome, were observed. All 3 cases that exhibited vertical dysfunction had upgaze limitation. One instance of nonpenetrance was recorded.

CONCLUSIONS

Considerable intrafamilial clinical variability was observed in this Duane syndrome pedigree that carried a alpha2-chimaerin mutation. The presence of bilateral involvement and associated vertical movements, which commonly are observed in this and other DURS2 families, could suggest the occurrence of CHN1 mutations as the source of the disease in isolated or familial DURS cases.

Duane retraction syndrome, nystagmus, retinal pigment epitheliopathy and epiretinal membrane with micro- and pachygyria, developmental delay, hearing loss and craniopharyngioma

PURPOSE

To report the association of Duane syndrome with nystagmus and a patterned hyperpigmentation of the retinal pigment epithelium, developmental delay, micro- and pachygyria and craniopharyngioma.

CASE REPORT

We describe a 12-year old girl with developmental delay, hearing loss, cortical micro- and pachygyria, and a cystic craniopharyngioma; her ocular features include unilateral Duane syndrome, monocular nystagmus under binocular conditions, and a patterned hyperpigmentation of the retinal pigment epithelium. Her mother had similar retinal pigment epithelial abnormalities.

CONCLUSIONS

The combination of two neuronal migrational disorders, the unusual retinal pigment epithelial abnormalities in the proband and her mother, and evidence that each feature may be genetic and are suggestive of a genetic basis for this constellation of features.

Auditory brainstem response and otoacoustic emissions in Duane retraction syndrome

OBJECTIVE

We aimed to investigate the origin of hearing loss with relevance to auditory brainstem responses and otoacoustic emissions in patients with Duane's retraction syndrome (DRS).

MATERIALS AND METHODS

17 patients with DRS were included in the study. 14 patients were diagnosed as DRS type 1 and the remaining three as type 3. The control group consisted of nine healthy subjects. Pure tone audiogram, auditory brainstem response, as well as distortion product otoacoustic emissions were recorded in all the patients and the controls.

RESULTS

Among the 17 patients with DRS, 15 demonstrated normal hearing according to pure tone audiogram. One patient with DRS had profound sensorineural hearing loss with a pure tone average of 110 dB, and one patient had moderate sensorineural hearing loss with a pure tone average of 60 dB. Auditory brainstem response latencies of the waves I, III and V, and interwave latencies were calculated in 15 patients with DRS and were compared with the control group. There was statistically significant increase in wave I latency of left ear in the DRS group compared to the controls (P<0.05). Amplitudes of distortion product otoacoustic emissions were also recorded at frequencies of 2, 3, 4, 6, and 8 kHz in both groups and the comparison of the DRS patients and controls revealed no statistically significant difference.

CONCLUSIONS

We recommend auditory examinations be undertaken in patients with DRS by auditory brainstem response tests, as well as distortion product otoacoustic emissions, whereas all patients with normal results should be followed-up for future hearing loss.

Duane retraction syndrome on the Arabian Peninsula

PURPOSE

To describe the clinical features of patients from the Arabian Peninsula with Duane retraction syndrome (DRS).

METHODS

Retrospective chart review of patients referred to the King Khaled Eye Specialist Hospital in Riyadh, Saudi Arabia from 1982 to 2003 with a diagnosis of DRS. Patients having had prior strabismus surgery were excluded.

RESULTS

Of 404 DRS patients, 347 (86%) were unilateral, 57 (14%) were bilateral, and 111 (27%) had amblyopia. There were 221 (55%) females and 182 (45%) males. The Huber classification was as follows: 315 (78%) Type I, 16 (4%) Type II, and 77 (19%) Type III. Of the 57 bilateral cases, 25 (44%) were female and 32 (56%) were male.

DISCUSSION

Overall, the clinical features of DRS patients referred to a Riyadh eye hospital are similar to those reported in series throughout the world. However, our referred bilateral DRS patients are more commonly male. The clinical features of bilateral DRS deserve further worldwide study.

Two pedigrees segregating Duane's retraction syndrome as a dominant trait map to the DURS2 genetic locus

PURPOSE

The genetic bases of Duane's retraction syndrome (DRS) were investigated to determine its molecular etiologies. In prior studies, the transcription factors SALL4 and HOXA1 were identified as the genes mutated in DRS with radial anomalies, and in DRS with deafness, vascular anomalies, and cognitive deficits, respectively. Less is known, however, about the genetic etiology of DRS when it occurs in isolation, and only one genetic locus for isolated DRS, the DURS2 locus on chromosome 2, has been mapped to date. Toward the goal of identifying the DURS2 gene, two pedigrees have been ascertained that segregate DRS as a dominant trait.

METHODS

Members of two large dominant DRS pedigrees were enrolled in an ongoing study of the genetic basis of the congenital cranial dysinnervation disorders, and linkage analysis was conducted to determine whether their DRS phenotype maps to the DURS2 locus.

RESULTS

By haplotype analysis, the DRS phenotype in each family cosegregates with markers spanning the DURS2 region. Linkage analysis reveals maximum lod scores >2, establishing that the DRS phenotype in these two pedigrees maps to the DURS2 locus.

CONCLUSIONS

These two pedigrees double the published pedigrees known to map to the DURS2 locus and can thus contribute toward the search for the DURS2 gene. The affected members represent a genetically defined population of DURS2-linked DRS individuals, and hence studies of their clinical and structural features can enhance understanding of the DURS2 phenotype, as described in the companion paper.

Vertical rectus muscle transposition for bilateral Duane syndrome

BACKGROUND

Augmented transposition of the superior and inferior rectus muscles to the lateral rectus muscle is effective surgical treatment for esotropia in unilateral Duane syndrome. Medial rectus muscle recession in bilateral Duane syndrome may increase the risk of consecutive exotropia and cause limitation to adduction postoperatively. Vertical rectus muscle transposition may be useful in bilateral Duane syndrome with esotropia.

METHODS

We undertook a retrospective review of 11 patients with bilateral Duane syndrome and esotropia in primary position. All patients had vertical rectus muscle transpositions. Six patients had unilateral vertical rectus transpositions (2 eyes with and 4 without suture augmentation). Twelve eyes from 7 children (2 unilateral and 5 bilateral) had transpositions augmented with posterior fixation sutures. Posterior fixation suture were added to large deviations in patients without prior medial rectus recessions.

RESULTS

The preoperative esotropia at distance was 22.8 +/- 6.3 prism diopters (PD). It reduced to 2.0 +/- 6.7 PD postoperatively. (P < 0.001) Esotropia at near changed from 21.0 +/- 5.8 PD preoperatively to 1.2 +/- 8.1 PD postoperatively. (P < 0.001) One patient with a 10-degree face turn had complete resolution postoperatively. One patient had a small undercorrection and developed a vertical deviation requiring additional surgery. All patients had improvement in abduction. Nine of 11 patients did not develop any limitation to adduction. One patient developed a -1 adduction deficit 5 years later. Three patients achieved fusion with a mean stereovision of 67 seconds of arc (range, 80-40 seconds.). Follow-up averaged 22.2 months (range, 1-100 months).

CONCLUSION

Vertical rectus muscle transposition in patients with bilateral Duane syndrome and esotropia is an effective procedure to improve ocular alignment and motility while preserving adduction.

The Clinical Features of Korean Patients with Duane's Retraction Syndrome

PURPOSE

To describe the clinical features of Duane's retraction syndrome (DRS) in Korean patients.

METHODS

We retrospectively analyzed the 78 DRS cases that presented to our department between 1995 and 2004. The clinical features investigated included sex distribution, laterality, type of presentation, deviation in primary position, anomalous vertical movements, face turn, amblyopia and anisometropia.

RESULTS

There were 38 (48.7%) affected males and 40 (51.3%) females. Left eye predominance (83.3%) was observed, as was type I presentation (85.9%). Orthotropia was found to be the most common primary position in 46 cases (59.0%). Face turn in unilateral DRS was noted in 13 patients (17.1%). There were 6 cases (7.7%) with anisometropia and 4 (5.1%) with amblyopia.

CONCLUSIONS

The clinical manifestations of DRS in our study were different from those of equivalent Caucasian studies yet similar to those previously reported for Asian groups. Racial and regional differences were noted, for which further research is needed to elaborate the reasons and mechanisms.

Autism associated with conditions characterized by developmental errors in early embryogenesis: a mini review

Autism is a complex developmental disorder without an established single etiology but with significant contributions from genetic studies, functional research, and neuropsychiatric and neuroradiologic investigations. The purpose of this paper is to review the findings in five studies involving individuals manifesting the characteristic findings of autism spectrum disorder associated with malformations and dysfunctions known to result from early embryogenic defects. These investigations include two associated with teratogens (thalidomide embryopathy, Mobius sequence with misoprostol) and three (most Mobius sequence cases, CHARGE association, Goldenhar syndrome) with no known etiology. These studies suggest that early embryonic development errors often involving cranial nerve palsies, internal and external ear malformations, ophthalmologic anomalies, and a variety of systemic malformations may be associated with autism spectrum disorders statistically more frequently than expected in a normal population. Although the exact time of developmental insult for each condition cannot be identified, the evidence is that it may occur as early as week 4 to 6+ of embryogenesis.

Applications of molecular genetics to the understanding of congenital ocular motility disorders

The congenital fibrosis syndromes (CFS), including congenital fibrosis of the extraocular muscles (CFEOM) and Duane syndrome (DS), are rare congenital strabismus syndromes that present with nonprogressive restrictive ophthalmoplegia with or without ptosis. Although historically believed to result from primary extraocular muscle (EOM) fibrosis, our laboratory's work is based on the hypothesis that these disorders result from distinct, but analogous, developmental defects of the oculomotor (nIII), trochlear (nIV), and abducens (nVI) nuclei. We have defined three inherited CFEOM phenotypes (CFEOM1-3) and have mapped each phenotype to a distinct genetic locus (FEOM1-3). Individuals with CFEOM1 are born with bilateral ptosis and both eyes fixed in a downward position with absent upgaze and aberrant horizontal gaze. This disorder maps to the FEOM1 locus on chromosome 12cen.(1,2) Neuropathology studies of CFEOM1 reveal the absence of the superior division of oculomotor nerve and its corresponding alpha motor neurons in the midbrain, with abnormalities of target EOMs.(3) These neuropathology findings parallel those previously identified in Duane syndrome, in which there is an absence of nVI and the abducens nerve.(4,5) Individuals with CFEOM2 are born with bilateral ptosis and exotropia. This atypical form of CFEOM maps to the FEOM2 locus on chromosome 11q13 and results from mutations in ARIX (PHOX2A).(6,7) ARIX encodes a homeodomain transcription factor protein previously shown to be required for nIII/nIV development in mouse and zebrafish.(8,9) Together, these findings support the hypothesis that the congenital fibrosis syndromes result from parallel defects in nIII, nIV, and nVI nuclear development. Functional studies of the CFEOM genes should provide additional insight into the unique features of the extraocular lower motor neuron axis in health and disease. (For full (refs. 1-9), see reference list of the main paper.)

Bilateral Duane syndrome with bilateral congenital glaucoma

Multiple ocular associations with Duane syndrome have been reported as summarized by DeRespinis et al. The most frequently noted include nystagmus, anisocoria, ptosis, optic nerve colobomas, and epibulbar dermoids. Less encountered abnormalities are optic nerve hypoplasia, heterochromia, and congenital cataract. To our knowledge, no reports of associated congenital glaucoma exist in the literature. We report a 10-year-old patient with bilateral Duane syndrome and bilateral congenital glaucoma who we have monitored for 7 months after birth.

Characteristics of Okihiro syndrome

PURPOSE

To describe Okihiro syndrome, a syndrome consisting of Duane's syndrome, radial ray anomaly, and sensorineural deafness.

METHODS

The incidence of anomalies in 41 individuals from 9 affected families was assessed by literature review and patient examination, and the frequency of the characteristics occurring together was determined.

RESULTS

Of all the individuals with at least one of the above characteristics, only 12% had all three characteristics. However, 44% had both Duane's syndrome and radial ray anomaly, whereas sensorineural deafness alone occurred in only 17% of patients.

CONCLUSION

Okihiro syndrome is consistent with autosomal dominance with variable penetrance, manifesting primarily with Duane's syndrome and radial ray anomaly, and less frequently, sensorineural deafness.

Congenital anomalies in patients with Duane retraction syndrome and their relatives

PURPOSE

Although the high incidence of skeletal, neural, and other ocular problems has been identified in previous reports of large cohorts of patients with Duane syndrome, there has not been any documentation of anomalies in close relatives. Patients with Duane syndrome have a greater than 50% incidence of associated abnormalities that include deafness, other ocular anomalies, cranial nerve palsies, and skeletal abnormalities. This study was undertaken to review the experience of our strabismus service with patients who have Duane retraction syndrome (DRS) and to delineate the associated anomalies in them and their first-degree relatives.

METHODS

A prospective study of all patients with Duane syndrome who were seen at the strabismus service at Moorfields Eye Hospital has been ongoing for the last 4 years. All patients were assessed for the presence of ophthalmologic features of DRS and then referred to the pediatric service for a physical and neurologic examination. First-degree relatives were also examined, and a family pedigree was generated.

RESULTS

We have evaluated 68 patients with DRS, of which 60.2% were female patients. The left eye was involved at a ratio of 4:1 in unilateral cases. The number of bilateral cases was 57.3%. Among the patients with DRS, 46% had first-degree relatives with associated abnormalities.

CONCLUSIONS

The high incidence of associated anomalies in patients and first-degree relatives may suggest that a common genetic defect is responsible. This has to be confirmed with molecular genetic studies, which were not performed on these families because of a lack of available resources. However, our findings may indicate that the inheritance of Duane syndrome is much higher than the 10% previously reported, if any congenital abnormality is accepted as DRS associated. Children with Duane syndrome may benefit from a full medical assessment, in view of the frequency of other abnormalities, and so may their siblings.

Clinical diversity of hereditary Duane's retraction syndrome

OBJECTIVE

To define the spectrum of ophthalmic manifestations of Duane's retraction syndrome (DRS) in a large family.

DESIGN

Cross-sectional study of 110 among 114 living relatives in an extended family.

METHODS

History and ophthalmic examination obtained on all participants.

MAIN OUTCOME MEASURES

Ocular motility, strabismus, visual acuity, binocularity, associated neurologic problems.

RESULTS

Twenty-five individuals were affected with DRS. Twenty-four subjects (96%) had bilateral DRS, but there was a broad spectrum of severity. Strabismus occurred in 76% and amblyopia in 48%. Associated findings included fourth cranial nerve palsy, partial third cranial nerve palsy, nystagmus, seizures, and deafness. Fourth cranial nerve palsies and manifest strabismus tended to cluster within single family units.

CONCLUSIONS

Strabismus and amblyopia are much more common with bilateral DRS than with unilateral DRS. There is much phenotypic variability among individuals within families with hereditary Duane's syndrome. The responsible gene(s) may affect the development of many cranial nerves. Genetic compounding may play a role in the phenotypic segregation seen within this large family.

Duane retraction syndrome associated with Rubinstein-Taybi syndrome

The authors present a case report of Duane retraction syndrome (DRS) associated with Rubinstein-Taybi syndrome (RTS). RTS is a multisystem condition characterized by psychomotor developmental delay, broad thumbs and great toes, short stature, and characteristic facies with a beaked nose. DRS is an ocular disorder characterized by retraction of the globe with narrowing of the palpebral fissure in attempted adduction, with abduction and/or adduction deficiency, and, frequently, upshoot or downshoot of the affected eye on adduction. The case report described represents the first reported case of DRS associated with RTS, an association not previously recognized. This association raises the possibility that the abnormal CNS development in RTS may occasionally involve the ocular motor nerves.

The heritability of strabismus

The etiology of strabismus has long been observed to have a genetic component. Recent advances in genetic methodology may provide insight into the genetic basis for several types of inherited strabismus, including those associated with genetic multisystem disorders such as Moebius syndrome, Prader-Willi syndrome, craniofacial dysostoses, and mitochondrial myopathies. Inheritance of primary forms of strabismus, such as congenital ocular fibrosis, Brown syndrome and Duane syndrome, has been reported, but less is known of the defective genetic sites. The genetic basis for isolated strabismus that clusters in families, such as infantile esotropia syndrome, is also not yet known, but new techniques of molecular biology may now permit linkage detection in these families. By identifying affected families, clinicians will take part in unraveling the genetic basis of hereditary strabismus syndromes.

Duane's retraction syndrome

Duane's retraction syndrome (DRS) has been a recognized clinical entity for nearly a century. It is a clinically well described ocular disorder consisting of retraction of the globe with narrowing of the lid fissure in attempted adduction, frequent abduction deficiency with variable limitation to adduction, and upshoot and/or downshoot of the affected eye on adduction. Among strabismus patients the incidence of DRS is probably not more than 5%. Most cases are sporadic, but familial cases have been estimated at 10% by most authors. Numerous theories concerning the etiology and pathogenesis of DRS have been proposed, including agenesis of the abducens nucleus, but the majority of investigators concur that the characteristic findings are best explained by a paradoxical innervation of the lateral rectus muscle, which subsequently causes a cocontraction of the horizontal rectus muscles. The frequent association of DRS with other congenital anomalies suggests a teratogenic event occurring between the fourth to eighth week of gestation as an etiological factor. In this review historical aspects and theories of the syndrome are studied and statistical data are compiled and analyzed. Clinical features, differential diagnoses and variants of the syndrome are examined. Testing and treatment objectives are discussed.

Ocular and systemic characteristics of Duane syndrome

The clinical features of 63 patients with Duane syndrome are described in this report. All data in the study were gathered retrospectively except for measurements of vertical palpebral fissure and axial eye length, which were investigated prospectively. The following new aspects of the syndrome are emphasized: 1) In most cases with heterotropia, the angle of deviation was not large (< or = 25 prism diopters). 2) Visual acuity of 0.66 (20/30) or better was recorded in 94% of the affected eyes. 3) Smaller palpebral fissure (by 1 mm or more) of the affected eye was measured in primary position among 9 of 40 (22%) unilateral cases. 4) The axial length of the affected eye (mean, 22.8 +/- 0.6 mm) was not significantly different from the uninvolved eye. 5) Two cases of heterochromia iridis (3.2%) were found among the Duane syndrome patients. 6) A 4.8% prevalence of high-tone hearing loss was detected, in addition to 4.8% of sensorineural deafness.

Thalidomide embryopathy: a model for the study of congenital incomitant horizontal strabismus

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Idiopathic superior oblique palsies in children

The records of 110 patients with superior oblique palsy seen at the Boston Children's Hospital between 1966 and 1988 were reviewed. Patients with identifiable orbital or neurological disorders affecting the fourth cranial nerve or with a history of head trauma preceding their superior oblique palsy were excluded from analysis. Patients were also excluded because of prior surgery elsewhere or insufficient diagnostic information. The remaining 63 patients were considered to have idiopathic superior oblique palsies. All 63 patients presented with unilateral palsies. All had incomitant hypertropia of the affected eye, greater on gaze to the contralateral side and increased by ipsilateral head tilt. Left eyes were affected in 41 patients. The age at first ophthalmological examination was spread over the first 20 years, with heavier representation in the first 5 years and decreasing numbers in each succeeding 5-year interval. Only one patient was found to have a masked bilateral superior oblique palsy following surgery for an apparent unilateral palsy. A distinction is made between unmasking a bilateral superior oblique palsy and surgical overcorrection of a unilateral palsy. The predominant unilaterality of idiopathic superior oblique palsies is in contrast to the reported frequency of bilaterality in traumatic cases.

Auditory function in Duane's retraction syndrome

We obtained audiograms and auditory brainstem responses from 44 patients with Duane's retraction syndrome to assess the incidence and nature of hearing deficit. Of 44 patients, seven (15.9%) had evidence of hearing impairment. Three (6.8%) subjects had a temporary conductive hearing loss because of middle ear fluid, and another patient had hearing loss from Crouzon's disease. The remaining three (6.8%) patients demonstrated sensorineural hearing deficit. This hearing impairment was attributed to a cochlear lesion and not to a pontine lesion. We believe that the frequency of sensorineural hearing loss in these patients warrants hearing screening programs similar to those used for infants in neonatal intensive care units.

Wildervanck's syndrome--unilateral Mondini dysplasia identified by computed tomography

We present a case of the Wildervanck (cervico-oculo-acoustic) syndrome exhibiting congenital deafness. Klippel-Feil anomaly and lateral rectus palsy with enophthalmos. Audiometry indicated a predominantly conductive loss which, because of masking difficulties, was assumed to be bilateral: an erroneous assumption supported by results of conventional petrous bone tomography which failed to demonstrate any abnormality of the inner ears. Computed tomography (CT), however, revealed a severe Mondini dysplasia of one ear, a condition which must be assumed to be associated with severe sensorineural hearing loss. Reconstructive middle ear surgery for the conductive loss on the other side was therefore contraindicated.

Duane syndrome associated with features of the cat-eye syndrome and mosaicism for a supernumerary chromosome probably derived from number 22

A 12-year-old boy with a supernumerary chromosome, probably derived from number 22, had typical features of Duane syndrome with limitation of abduction and retraction of the globe upon adduction. Additionally, the patient had antimongoloid slant of the eyes, epicanthal folds, preauricular sinuses, cardiac malformations, skeletal malformations, and mental retardation suggestive of the cat-eye syndrome. The cat-eye syndrome has been often associated with a supernumerary chromosome derived from number 22. Our patient's karyotype was 46,XY/47,XY, + mar, with the supernumerary chromosome probably derived from number 22. These findings supplement previous findings of chromosome 22 abnormality associated with an ocular motility disorder.

Familial Brown's syndrome

We present findings in two siblings with bilateral Brown's syndrome and review other reported familial cases.

Familial congenital superior oblique palsy

Four pedigrees, each with two or more cases of congenital superior oblique palsy among immediate family members, are presented. Except for a single case report in 1926, this disorder has not been known to occur in a hereditary manner. Theories of pathogenesis of congenital fourth cranial nerve palsy are discussed, with special reference to the hereditary occurrence of this disorder. Analogy is drawn between the familial forms of congenital superior oblique palsy and Duane's syndrome.

Cervico-oculo-acoustic syndrome

A 12-year-old boy with the cervico-oculo-acoustic syndrome, which comprises Duane retraction syndrome, Klippel-Feil anomaly (fused cervical vertebrae) and congenital hearing loss, is described. To this classical triad an optic nerve head coloboma was associated. To the authors' knowledge this is the first case in which such an association has been recorded.

The Okihiro syndrome of Duane anomaly, radial ray abnormalities, and deafness

We report on a child with Duane anomaly, deafness, cervical spine, and radial ray abnormalities. A sister of the proposita had hemifacial microsomia, cervical abnormalities, and hypoplasia of the thenar eminence. Four relatives had hypoplasia of the thenar eminence. A fifth had preaxial polydactyly. Duane anomaly was present in two sixth-degree relatives. This appears to be an autosomal dominant trait. Singly or in combination the abnormalities seen in this family have all been described in association with Duane anomaly. Their occurrence in the same family suggests that they are not independent entities but represent pleiotropic effects of the same gene.

Congenital crocodile tears: a key to the aetiology of Duane's syndrome

The occurrence from birth of copious lacrimation on eating in some patients with Duane's syndrome suggests that both are caused by dysgenesis or a lesion in the vicinity of the abducens nucleus in the pons.