Typical ocular coloboma affects three generations in one family

We found bilateral colobomas of the iris, choroid, retina, and optic nerve head in a son, mother, and grandmother in one pedigree. This represents a rare incidence of typical ocular coloboma in three generations.

[Möbius syndrome and bilateral chorioretinal coloboma]

A child with palsy of the right facial nerve and bilateral palsy of the VIth, IXth and XIIth cranial nerves, dysfunction of the VIIIth cranial nerve, facial malformations and bilateral equinovarus was diagnosed on the basis of these features as having Moebius syndrome. Ocular studies disclosed congenital cataract and chorioretinal coloboma in both eyes. These ocular abnormalities have not previously been described in Moebius syndrome. This paper discusses whether the coexistence of these two types of anomalies may be due to occurrence of a break in the primitive internal carotid and trigeminal arteries between the fourth and fifth postconceptional weeks, causing maldevelopment of the choriocapillary and impairing neuron differentiation in cranial nerve nuclei.

Bilateral macular coloboma and pigmented paravenous retinochoroidal atrophy

A patient had bilateral macular coloboma with aggregations of pigment clumps located perivascularly, predominantly paravenously, and in other parts of the retina. The Toxoplasma IgG antibody was negative. The diagnosis of bilateral macular coloboma with pigmented paravenous retinochoroidal atrophy was made and seemed to be a developmental abnormality in origin.

Possible new type of oral-facial-digital syndrome with retinal abnormalities: OFDS type (VIII)

The most recent classification of the oral-facial-digital syndromes (OFDS) includes 7 types distinguishable by different clinical signs. We describe 2 brothers presenting oral, facial, and digital anomalies and an additional manifestation consisting of specific retinal abnormalities, i.e., retinochoroideal lacunae of colobomatous origin. Our patients may be affected with a new type of OFDS, i.e., OFDS type VIII, characterized by eye abnormalities in addition to other manifestations that partially overlap with those of OFDS type II. Given that there are 2 affected brothers, we cannot distinguish between autosomal and X-linked recessive inheritance.

Photoreceptor transplantation: anatomic, electrophysiologic, and behavioral evidence for the functional reconstruction of retinas lacking photoreceptors

We have investigated the possibility of using transplantation of immature or mature rodent photoreceptors as well as mature human photoreceptors to reconstruct retinas in which photoreceptor degeneration is either inherited or environmentally induced. To this end, we have devised methods for isolating and transplanting the outer nuclear layer (ONL) (e.g., the photoreceptor layer) to the subretinal space of mature rodents. In addition we found that if portions of the inner retina are transplanted along with the intact photoreceptor sheet, photoreceptor organization is better maintained. In ultrastructural studies of the reconstructed retina an outer plexiform-like layer (OPL) is visible at the interface of the transplanted ONL and the host inner nuclear layer, with invaginating ribbon synapses characteristic of those formed by rod photoreceptors evident within this OPL. Ribbon synapses are found only rarely in unreconstructed retina. These results suggest that synaptic connections between transplanted photoreceptors and host cells may be made. Evidence for the potential recovery of function following photoreceptor transplantation is found in visually evoked cortical responses and behavioral responses (pupillary reflex) to light stimulation of the reconstructed eye. These findings suggest the possibility that neural transplantation can reconstruct a sensory end organ--in this case the retina--to restore evoked activity and an appropriate behavioral response to sensory stimulation.

Walker-Warburg syndrome

The Walker-Warburg syndrome (WWS) is a rare autosomal recessive disorder characterized by lissencephaly, cerebellar and retinal malformations, and congenital muscular dystrophy. We report a new case of WWS identified with the aid of cranial MR and briefly review the radiologic findings of this lethal syndrome.

Linkage analysis of Norrie disease with X-chromosomal ornithine aminotransferase

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A new case of acro-renal-ocular (radio-renal-ocular) syndrome with cleft palate and costo-vertebral defects? A brief clinical report

The authors describe a girl with retarded growth, renal malformations, retinal coloboma and hypoplasia of the thumbs like reported in the acro-renal-ocular syndrome. In addition, they found defects of the ribs and spine and cleft palate, not previously described in this syndrome. The was noted to have minor anomalies of the hands, which might represent a mild manifestation of this autosomal dominant syndrome.

Oto-palatal-digital syndrome type II with X-linked cerebellar hypoplasia/hydrocephalus

We describe an infant with clinically apparent oto-palatal-digital syndrome Type II (OPD II), who, in addition, also has hydrocephalus and cerebellar hypoplasia. This second X-linked disorder has not been reported previously to occur in association with OPD II. This patient had 2 maternal uncles who died neonatally with congenital hydrocephalus and digital abnormalities consistent with OPD II. We suggest that these 2 entities may be located near one another on the X chromosome, and that both loci are affected in this family.

Chorioretinal lacuna in the amniotic band syndrome

The malformations in the amniotic band syndrome (ABS) are due to entrapment of fetal parts by fibrous band in the amniotic sac. Limbs are most commonly affected followed by craniofacial defects in one third of patients. Ocular defects include corneal leukomas and lid colobomas often contiguous with facial clefts, strabismus, hypertelorism, and microphthalmos. Unilateral chorioretinal defects or lacunae are rare findings in the ABS. We report a female infant with such a lacunar defect along with central nervous abnormalities, and discuss the differential diagnosis and the embryopathic implications.

Ultrastructural study of Norrie's disease

We studied the clinicopathologic and ultrastructural features of a full-term infant with Norrie's disease. The infant had bilateral retrolental fibrous vascular masses and retinal detachment with no other apparent physical abnormalities and no family history of ocular defects. A vitrectomy and a membrane peeling were attempted, and specimens of the retina, the retrolental membrane, and a vascularized epiretinal peripheral mass were examined by light and electron microscopy. The retrolental membrane was composed of layered collagenous tissue and contained structures resembling blood vessels. Inner and outer neuroblastic layers were identified in the retinal tissue, but no vessels were present. In the epiretinal mass, portions of retina and cortical vitreous were seen along with primitive vascular structures. The histologic appearance of these specimens suggests that the major pathologic event of Norrie's disease occurs in the retina in the third to fourth gestational month. We believe the subsequent ocular abnormalities found in this patient were secondary to this early retinal malformation and did not represent a progressive ocular disorder.

Developmental abnormalities in transgenic mice expressing a sialic acid-specific 9-O-acetylesterase

9-O-acetylation of sialic acids is tissue specific and developmentally regulated. We have selectively destroyed these O-acetyl groups during murine embryogenesis by expressing the 9-O-acetyl-sialic acid-specific esterase of influenza C. DNA constructs driven by the metallothionein promoter arrested development at the 2-cell stage and gave a markedly decreased yield of live mice. A similar construct driven by the phenylethanolamine-N-methyltransferase promoter did not cause this block, but gave transgenic mice with selective expression of esterase in the retina and the adrenal gland. These organs showed variable abnormalities in organization, while all other tissues examined appeared normal. The ganglioside 9-O-acetyl-GD3 was selectively destroyed in target tissues. Thus, 9-O-acetylated sialic acids may play an role in murine development at the 2-cell stage and in certain differentiated tissues.

RPE dysplasia with retinal duplication in a mutant mouse strain

An autosomal dominant mutation was produced by quadruple gonadal exposure of a male (C3H x 101)F1 mouse to 500 rad of X-irradiation. This mutation is maintained by the mating of affected heterozygous males to normal (C3H x C57B1)F1 females. Clinically apparent abnormalities were limited to the eyes and, in the affected adults, ranged from apparent anophthalmia to globes that were enlarged and exhibit large uveoscleral colobomas. Sequential evaluations of the embryogenesis of this condition have identified abnormal differentiation of the outer layer of the optic cup (presumptive retinal pigment epithelium-RPE) into a second layer of neural retina. The abnormality is identified as early as day 10 of gestation, during invagination of the optic cup and lens placode. The area of RPE dysplasia may be diffuse or regional with an abrupt transition from normal RPE and often demonstrates excessive and uncontrolled proliferation. The two symmetrical, apposed layers of photoreceptors fail to differentiate and begin to degenerate prenatally. Absence of normal RPE leads to failure of induction of adjacent choroid and sclera, resulting in a posterior segment consisting of a large neuroepithelial-lined cyst. Radiation-induced ocular malformations of this type have not been previously described. In addition, this model presents a unique opportunity to examine the processes leading to differentiation of a single, continuous epithelial layer into tissues as anatomically and functionally distinct as neural retina and RPE.

Bilateral Norrie's disease in identical twins

A case of Norrie's disease in an identical twins is reported. No positive family history was obtained. The couple had no other children. The older of the twins died at the age of 9 months of uncertain cause. To the best of my knowledge this is the first case of Norrie's disease reported in Malaysia. And its occurrence in an identical twins is very rare.

Retinochoroidal coloboma and subretinal neovascularization

Subretinal neovascularization associated with retinochoroidal coloboma is rare. To the authors' knowledge, only three cases have been reported. We report a new case of isolated subretinal neovascularization and coloboma in a 26-year-old woman without other causes of choroidal neovascularization. Only the disruption of the normal retinal anatomy could explain the development of this subretinal neovascularization.

Plasma amine oxidase activities in Norrie disease patients with an X-chromosomal deletion affecting monoamine oxidase

Two individuals with an X-chromosomal deletion were recently found to lack the genes encoding monoamine oxidase type A (MAO-A) and MAO-B. This abnormality was associated with almost total (90%) reductions in the oxidatively deaminated urinary metabolites of the MAO-A substrate, norepinephrine, and with marked (100-fold) increases in an MAO-B substrate, phenylethylamine, confirming systemic functional consequences of the genetic enzyme deficiency. However, urinary concentrations of the deaminated metabolites of dopamine and serotonin (5-HT) were essentially normal. To investigate other deaminating systems besides MAO-A and MAO-B that might produce these metabolites of dopamine and 5-HT, we examined plasma amine oxidase (AO) activity in these two patients and two additional patients with the same X-chromosomal deletion. Normal plasma AO activity was found in all four Norrie disease-deletion patients, in four patients with classic Norrie disease without a chromosomal deletion, and in family members of patients from both groups. Marked plasma amine metabolite abnormalities and essentially absent platelet MAO-B activity were found in all four Norrie disease-deletion patients, but in none of the other subjects in the two comparison groups. These results indicate that plasma AO is encoded by gene(s) independent of those for MAO-A and MAO-B, and raise the possibility that plasma AO, and perhaps the closely related tissue AO, benzylamine oxidase, as well as other atypical AOs or MAOs encoded independently from MAO-A and MAO-B may contribute to the oxidative deamination of dopamine and 5-HT in humans.

Heterotopic ciliary epithelial differentiation in a patient with trisomy 13

A premature infant was born with congenital anomalies suggestive of trisomy 13, confirmed by karyotype analysis. Pathologic examination of the eyes revealed typical features of trisomy 13, including microphthalmos, extensive colobomata, and retinal dysplasia. A heterotopic ciliary body had also developed in the posterior segment of the left eye in the region of the posterior coloboma. The development of a well-formed ciliary body in the posterior segment of the eye questions the hypothesis that physical contact between the lens primordium and neuroepithelium is required for ciliary body development.

The development of the eye in homozygotes of the mouse mutant Extra-toes

Mice homozygous for the Extra-toes mutation (Xt/Xt) die perinatally with multiple malformations involving the brain, the eye, the nasal mucosa, the face and the skeleton. We have investigated the development of the eye defect in Xt/Xt embryos until late gestation In early midgestation, three classes of homozygotes can be identified: some form an apparently normal optic cup and are associated with an apparently normal lens vesicle, some have distorted optic cups with abnormal and small lens vesicles, and others do not form an optic cup and have no lens placode or vesicle. In late gestation, some embryos have obviously continued to develop small eyes, which develop coloboma because the optic fissure in the optic nerve does not close. The others show degeneration of the optic nerve and eye cup, with no remnants of lenses. Even in the absence of an eye in these mutants, extra-ocular muscles develop. Upon comparison with other mouse mutants with eye defects, our data suggest that the malformation of the eye in Extra-toes homozygotes is due to the defective optic vesicle, and not as previously stated because of generic forces interfering with lens induction.

Ultrastructure of murine trisomy 1 optic cup

The optic cups of two gestational day 11 trisomy (ts) 1 mouse embryos and a normal littermate control were examined using transmission electron microscopy (TEM). One trisomic embryo had a small lens with a lens stalk; the other was aphakic. The resolution available with TEM allowed detailed evaluation of cell organelles, spatial relationships, and the intra- and extracellular structural environment of the optic cup in normal and abnormal mouse embryos. Differences between the normal littermate and the trisomic optic cups, as well as between the two ts 1 structures, included the following: 1) melanin granules in the retinal layer and intraretinal space as well as in the pigment layer, 2) neither pseudostratified nor cuboidal neuroepithelium in trisomic optic cups, 3) increasing cell lysis with severity of eye defect, 4) fusion between retinal and pigment layer cells and cells from the pigment layer and head mesoderm. This investigation not only confirmed some of the abnormal morphology found in light microscopic studies of ts 1 at this gestational age but also identified other anomalies in the ts 1 eye that may play a part in the dysgenesis of this organ. The roles of larger than normal intercellular lacunae, disorganized microtubules, and the connections between different cell types in the ts 1 optic cup require further investigation.

Microphthalmia and chorioretinal lesions in a girl with an Xp22.2-pter deletion and partial 3p trisomy: clinical observations relevant to Aicardi syndrome gene localization

We present a 4-year-old girl with a maternally derived, unbalanced X;3 translocation resulting in partial Xp monosomy and partial 3p trisomy. She had chorioretinal defects, developmental delay, infantile seizures, and microphthalmia. These findings initially suggested a diagnosis of Aicardi syndrome. However, she had a normal-appearing corpus callosum on CT and magnetic resonance imaging scans of the brain and her retinal findings were not typical for Aicardi syndrome. This represents the 6th reported example of microphthalmia associated with an Xp22 chromosome abnormality. Four of these individuals also had features suggestive of focal dermal hypoplasia (FDH), which was not evident in our patient. The available evidence supports the hypothesis that gene disruption at Xp22 may lead to findings similar to those seen in Aicardi syndrome and FDH, both of which are believed to be X-linked dominant male lethal conditions.

[Chorioretinal coloboma and neovascular membrane]

Retinochoroidal coloboma results from an incomplete closure of the ocular embryonic fissure. Uni or bilateral, the coloboma can be associated with cataract, microphthalmia, retinal detachment... but rarely with neovascularization. This association is comparable with subretinal neovascularization in high myopia, angioid streaks, choroiditis and choroidal ruptures. The disruption of the normal anatomy of the Bruch's membrane is a possible entry site of choroidal blood vessels. But the reason why only rare cases are reported is unknown.

Rieger anomaly and uveal coloboma with associated anomalies. Third observation of a rare oculo-palato-osseous syndrome--the Abruzzo-Erikson syndrome

The authors report a girl with short stature, goniodysgenesis, bilateral iridochorio-retinal coloboma, associated with facial and acral anomalies, and borderline intelligence. Anterior chamber defect and face dysmorphism are in accordance with the diagnosis of Rieger syndrome. Some features are reminiscent of the CHARGE association. Coloboma, abnormal ears, grooved palate, elbow pronosupination and hand bones anomalies are related to the Abruzzo-Erikson syndrome. The authors postulate that their propositus may represent a new occurrence of the latter syndrome, and they propose to widen the actual definition of Abruzzo-Erikson syndrome to the association of goniodysgenesis, coloboma, abnormal ears and upper limb anomalies.