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Biomedical subjects

I H Maumenee

Publications and source records attributed to I H Maumenee.

At least 37 records · Page 2Linked to original sources

Familial Axenfeld-Rieger anomaly, atrial septal defect, and sensorineural hearing loss: a possible new genetic syndrome.

OBJECTIVE: To describe the clinical and ocular histopathological findings in multiple members of a family with congenital Axenfeld-Rieger anomaly, atrial septal defect, and sensorineural hearing loss. METHODS: We performed a retrospective review of the medical charts and the ocular histopathological material of multiple members of a family. RESULTS: Congenital Axenfeld-Rieger anomaly and glaucoma were inherited by both the proband and her male half-sibling from a phenotypically positive father and 2 different phenotypically negative mothers, suggesting an autosomal dominant inheritance. The proband's male half-sibling and her father also had atrial septal defects and sensorineural hearing loss. The proband's paternal grandmother had severe glaucoma. Histopathological analysis of blind, painful eyes removed from the proband's father and paternal grandmother showed incomplete development of the anterior chamber angle with iris stromal hypoplasia, prominent posterior embryotoxon with iris adhesions, and abnormal position and insertion of the ciliary muscles. CONCLUSIONS: This is the first description of coexisting Axenfeld-Rieger anomaly, atrial septal defect, and sensorineural hearing loss in multiple members of a single family. The iris, trabecular meshwork, and large portions of the cardiac intraventricular septum all arise from neural crest anlagen, thus supporting the notion that anterior segment dysgenesis represents a developmental disorder of the neural crest.

Abnormalities, Multiple↗

Clinical features of autosomal dominant congenital nystagmus linked to chromosome 6p12.

PURPOSE: To describe the clinical features of a large pedigree with autosomal dominant congenital nystagmus linked to chromosome 6p12. METHODS: In a prospective evaluation of 54 living family members in a single pedigree, 21 persons were affected with autosomal dominant congenital nystagmus, and clinical examinations were performed on 14. Selected persons underwent further studies, including electroretinography, scanning laser ophthalmoscopy, nerve fiber layer studies, visual evoked potential studies, and eye movement recordings. RESULTS: Among seven affected persons whose parents were able to report whether the nystagmus was present congenitally, onset at birth was noted in two persons and between 3 and 6 months in five persons. Best-corrected binocular Snellen visual acuity ranged from 20/30 to 20/100, with a mode of 20/50. Strabismus was present in 14 examined patients (36%). Eye movement recordings, performed on five persons, included asymmetric pendular (three), asymmetric pendular combined with dual waveform jerk (one), and unidirectional jerk nystagmus (one). CONCLUSIONS: Autosomal dominant congenital nystagmus represents a disorder with variable expressivity. While onset is typically during infancy, it can be noted at birth. Intrafamilial variation in visual acuity, ocular alignment, and nystagmus waveform suggests a role for modifying influences on expression of disease.

Adult↗

Assessment of the interphotoreceptor matrix proteoglycan-1 (IMPG1) gene localised to 6q13-q15 in autosomal dominant Stargardt-like disease (ADSTGD), progressive bifocal chorioretinal atrophy (PBCRA), and North Carolina macular dystrophy (MCDR1).

We have recently characterised the genomic organisation of a novel interphotoreceptor matrix proteoglycan, IMPG1, and have mapped the gene locus to chromosome 6q13-q15 by fluorescence in situ hybridisation. As the interphotoreceptor matrix (IPM) is thought to play a critical role in retinal adhesion and the maintenance of photoreceptor cells, it is conceivable that a defect in one of the IPM components may cause degenerative lesions in retinal structures and thus may be associated with human retinopathies. By genetic linkage analysis, several retinal dystrophies including one form of autosomal dominant Stargardt-like macular dystrophy (STGD3), progressive bifocal chorioretinal atrophy (PBCRA), and North Carolina macular dystrophy (MCDR1) have previously been localised to a region on proximal 6q that overlaps the IMPG1 locus. We have therefore assessed the entire coding region of IMPG1 by exon amplification and subsequent single stranded conformational analysis in patients from 6q linked multigeneration families diagnosed with PBCRA and MCDR1, as well as a single patient from an autosomal dominant STGD pedigree unlinked to either of the two known STGD2 and STGD3 loci on chromosomes 13q and 6q, respectively. No disease associated mutations were identified. In addition, using an intragenic polymorphism, IMPG1 was excluded by genetic recombination from both the PBCRA and the MCDR1 loci. However, as the autosomal dominant Stargardt-like macular dystrophies are genetically heterogeneous, other forms of this disorder, in particular STGD3 previously linked to 6q, may be caused by mutations in IMPG1.

Adult↗

Demonstration of exclusive cilioretinal vascular system supplying the retina in man: vacant discs.

PURPOSE: To report the fluorescein angiographic and Doppler ultrasonographic findings in a patient with apparent exclusive ciliary vascular supply of the retina of both eyes. METHODS: Case report. RESULTS: The ophthalmoscopic appearance of all arterial vessels emanating from both discs was consistent with a cilioretinal origin. Retinal veins also entered each disc peripherally near the margin, leaving the central part of each disc vacant. Fluorescein angiography showed filling of all arterial vessels simultaneous with the early-phase choroidal background flush bilaterally. Color and power Doppler ultrasonographic imaging demonstrated unequivocally the absence of central retinal vessels within the optic nerves. Both discs were normal in size and excavated with central glial tissue present. The clinical history of monocular, alternating episodes of failing vision with partial resolution and the retinal pigmentation patterns bilaterally were consistent with, though not conclusive for, previous episodes of serous retinal detachments. Coincident systemic anomalies consisted of small kidneys with reduced renal parenchyma discovered on ultrasonography, along with chronic interstitial nephritis. CONCLUSIONS: The ophthalmoscopic appearance of optic discs with apparent all-cilioretinal vascular supply has been reported previously, but proof of the absence of central retinal vessels requires Doppler ultrasonographic evidence corroborated by angiographic findings, as exemplified in our case report. We describe the association of this disc anomaly with renal parenchymal disease and its distinction from colobomatous defects.

Aged↗

Autosomal dominant cerulean cataract is associated with a chain termination mutation in the human beta-crystallin gene CRYBB2.

Congenital cataracts are a common major abnormality of the eye that frequently cause blindness in infants. At least a third of all cases are familial; autosomal dominant congenital cataract (ADCC) appears to be the most common familial form in the Western world. Cerulean cataracts have peripheral bluish and white opacifications in concentric layers with occasional central lesions arranged radially. Although the opacities may be observed during fetal development and childhood, usually visual acuity is only mildly reduced until adulthood, when lens extraction is generally necessary. We have been studying a family (ADCC-1) with cerulean blue ADCC, in which the affected daughter of a first cousin mating was presumed to be homozygous for the cataract gene. Recently, we mapped an ADCC gene in this family to a region of chromosome 22 containing three beta-crystallin genes. Here we report that a chain-termination mutation in CRYBB2 is associated with ADCC in this family.

Amino Acid Sequence↗

Neuro-ophthalmic genetics.

Mutations in nuclear or mitochondrial DNA may cause disorders of neuro-ophthalmic significance. These include disorders of the optic nerve, such as Leber's hereditary optic neuropathy and Kjer-type optic atrophy, and disorders of ocular motility, such as congenital nystagmus, autosomal dominant progressive external ophthalmoplegia, and oculopharyngeal muscular dystrophy. In addition to more accurate disease classification and diagnosis, identification of genetic loci, genes, and their mutations has stimulated investigation into factors influencing disease expression and penetrance.

Animals↗

A gene for autosomal dominant congenital nystagmus localizes to 6p12.

Congenital nystagmus is an idiopathic disorder characterized by bilateral ocular oscillations usually manifest during infancy. Vision is typically decreased due to slippage of images across the fovea. As such, visual acuity correlates with nystagmus intensity, which is the amplitude and frequency of eye movements at a given position of gaze. X-linked, autosomal dominant, and autosomal recessive pedigrees have been described, but no mapping studies have been published. We recently described a large pedigree with autosomal dominant congenital nystagmus. A genome-wide search resulted in six markers on 6p linked by two-point analysis at theta = 0 (D6S459, D6S452, D6S465, FTHP1, D6S257, D6S430). Haplotype analysis localizes the gene for autosomal dominant congenital motor nystagmus to an 18-cM region between D6S271 and D6S455.

Chromosome Mapping↗

The Castroviejo square graft.

The histopathologic features of three keratoplasty specimens from three cases involving square graft procedures performed by Dr. Castroviejo are reported. Light and electron microscopy were performed. In two of the cases, repeat keratoplasties were performed because of recurrent corneal dystrophies. In the third case, a repeat keratoplasty was performed because of graft failure.

Aged↗

Immunohistochemical localization of fibrillin in human ocular tissues. Relevance to the Marfan syndrome.

OBJECTIVE: To better understand the ocular manifestations of the Marfan syndrome, we investigated the distribution of fibrillin in normal human ocular tissues. Fibrillin, a microfibrillar glycoprotein component of the extracellular matrix, has been found to be the defective gene product in the Marfan syndrome. METHODS: Frozen sections from seven pairs of normal eyes were stained with mouse anti-human fibrillin antibodies using the avidin-biotin immunoperoxidase technique. RESULTS: In the anterior segment, the following exhibited positive staining for fibrillin: the lens capsule and zonules; connective tissues of the iris, ciliary body, ciliary processes, and conjunctiva; and the basement membrane regions of the corneal epithelium and endothelium of Schlemm's canal. Posteriorly, fibrillin localized to the lamina cribrosa, sclera, choroid, and Bruch's membrane. CONCLUSIONS: Fibrillin is widely distributed in ocular connective tissues. The implications of defects in these tissues and the resultant ocular abnormalities in the Marfan syndrome such as ectopia lentis and glaucoma are discussed.

Aged↗

Effects of strabismus surgery on refraction in children.

We assessed 115 eyes of 59 children with esotropia 2-3 months postoperatively to evaluate the effects of strabismus surgery on refraction. Three variables were measured: spherical equivalent, and cylinder power and axis. The mean changes in spherical equivalent were non-significant. The axis of postoperative astigmatism moved towards 'with-the-rule', thus improving refraction. The amount of recession and the consequent changes in cylinder power were inversely related. The results showed a significant change in cylinder axis after recession of the inferior oblique. Recession-tucking procedures led to the largest changes in cylinder power.

Astigmatism↗

Photoaversion in Leber's congenital amaurosis.

Photoaversion is a prominent symptom of a number of infantile genetic ocular disorder such as congenital glaucoma, aniridia, albinism, and cone dystrophies including achromatopsia. Photoaversion has not been widely recognized as a clinical feature of Leber's congenital amaurosis. We present two patients who were diagnosed clinically with achromatopsia because of nystagmus, absent color vision, reduced visual acuity, and moderately severe photoaversion in the absence of anterior segment abnormalities. The photopic and scotopic responses of the electroretinogram (E R G) were nonrecordable in both patients indicating involvement of both cone and rod systems. The diagnosis was then revised to one of Leber's congenital amaurosis. Photoaversion can be a prominent clinical feature in some patients with Leber's congenital amaurosis. The E R G clinches the diagnosis. These patients may constitute a distinct genetic subtype of the disease and molecular genetic studies will help resolve this issue.

Blindness↗

Strabismus in the Marfan syndrome.

We studied 573 patients with the Marfan syndrome for the presence of ocular misalignment, refractive errors, and amblyopia. A total of 110 patients (19.2%) had strabismus. Of 573 patients, exotropia occurred in 67 (11.7%), esotropia in 12 (2.1%), vertical deviations in eight (1.4%), and primary inferior oblique muscle overaction in three (0.5%). Of 67 patients with exotropia, 18 had anisometropia and 39 had amblyopia. Of the 12 patients with esotropia, four had amblyopia and none had anisometropia. Exotropia and esotropia are more common in patients with the Marfan syndrome than in the general population of the United States (P < .001 for exotropia and .05 < P < .10 for esotropia). Abnormal afferent visual inputs to cortical centers caused by ectopia lentis, craniofacial abnormalities, and mechanical and genetic factors may all contribute to the higher prevalence of strabismus in this disease.

Adolescent↗

Ocular findings in trigonocephaly.

BACKGROUND: Trigonocephaly, caused by premature closure of the metopic suture, is a rare form of craniosynostosis. The aim of this study was to assess the visual outcome in children operated on for trigonocephaly. METHODS: We present eight cases of children with trigonocephaly surgically corrected by the same craniofacial technique. CT with 3D reconstruction was performed in all cases. Genitori defined three types of trigonocephaly according to the severity of the deformity of the skull base only types II and III were included in this study directed at evaluation of the ocular disorder. A complete eye examination was performed on all children by the same observer, with a follow-up of 2-6 years. RESULTS: 3D-CT reconstruction of the skull base showed that the frontozygomatic region was affected by the deformation. Ocular examination showed considerable astigmatism in most children with late operation. A low degree of strabismus was observed in most children. CONCLUSION: This study demonstrated that reconstructive surgery should be performed by the age of 6 months, given the immaturity of the visual system up to that time. Close cooperation between neurosurgeons, pediatricians and ophthalmologists is of paramount importance in order to prevent this bone deformation exerting an adverse effect on visual development. The ophthalmologist must possess a basic understanding of the various craniosynostoses.

Astigmatism↗

Visual outcome after surgery for Peters' anomaly.

The authors reviewed the charts of 22 patients with Peters' anomaly. Various surgical procedures were performed on 30 eyes of 18 patients (mean number of procedures = 3.3 per eye). Follow-up averaged six years. Visual acuity varied widely, with six eyes having an acuity of 20/400 or better, and 11 eyes with no light perception. Concomitant or secondary glaucoma required a greater number of surgical procedures (4.1 vs 3.4) per eye and was associated with a poorer visual outcome. No eyes with glaucoma had visual acuity better than 20/400. In bilaterally operated patients, visual results in one eye were independent of the outcome of the fellow eye. The range of visual acuity in bilaterally operated patients was similar to the vision in those operated unilaterally. Visual outcome in patients with Peters' anomaly remains guarded. With modern surgical techniques and aggressive attempts at visual rehabilitation, many patients may benefit from surgery. Some patients may have moderately good visual acuity for months or years before vision is lost. In the interim they may learn tasks they may not have otherwise acquired.

Cataract Extraction↗

Visual prognosis in autosomal dominant optic atrophy (Kjer type).

We examined 25 patients from three pedigrees with dominant optic atrophy (Kjer type). Follow-up on 20 patients ranged from five to 40 years (mean, 16 years; median, 13 years). Visual acuity ranged from 20/20 (in one 58-year-old man with an affected father and three affected children) to 20/400. The median initial visual acuity was 20/60, and the median final visual acuity was 20/80. Visual acuity remained unchanged or decreased by one Snellen line in both eyes of 13 patients (65%); it decreased between two and four Snellen lines in only one eye in three patients (15%) and in both eyes in four patients (20%). The rate of visual loss was unrelated to initial visual acuity or the particular pedigree to which the patient belonged. There was functional and ophthalmoscopic heterogeneity between and within the pedigrees. Eight patients perceived moderate to severe social or occupational handicap. Visual prognosis is relatively good in Kjer's dominant optic atrophy with stable or slow progression of visual loss.

Adolescent↗

Anterior segment malformations in 18q- (de Grouchy) syndrome.

The authors examined two patients with deletions of the terminal end of the long arm of chromosome 18. The ocular findings in one patient with 46, XX, del 18 (q21) consisted of hypertelorism, epicanthus, strabismus, myopia, microphthalmia, microcornea, corneal opacities, iris hypoplasia with full thickness defects, corectopia and large peripapillary staphylomata. The second patient with 46, XX, del (18) (pter --> q21.2 :: q22 --> qter), inv (21) (q21 --> p12 :: q21 --> qter) only had epicanthus, strabismus, myopia and peripapillary crescents. Based on the findings in these two patients and on a review of previously reported patients with del 18 qter it appears that the loss of band 18q23 may be responsible for malformations of the anterior segment in the 18q-syndrome.

Anterior Eye Segment↗

[Possible origins of the gene of Hermansky-Pudlak in Puerto Rico].

Five out of six albino persons in Puerto Rico suffer from the Hermansky-Pudlak syndrome. This syndrome has been reported also in other countries such as Great Britain, the Netherlands, Belgium, and Mexico, among others. Due to the geographical isolation of the island it is likely that these patients share a common ancestor. In explaining how the gene may have arrived to Puerto Rico the following possibilities are considered: (1) British soldiers attacking the island since 1595. (2) Dutch attackers in 1625. (3) aboriginal tribes. (4) slave traders.

Albinism, Oculocutaneous↗

Genetic heterogeneity among blue-cone monochromats.

Thirty-three unrelated subjects with blue-cone monochromacy or closely related variants of blue-cone monochromacy were examined for rearrangements in the tandem array of genes encoding the red- and green-cone pigments. In 24 subjects, eight genotypes were found that would be predicted to eliminate the function of all of the genes within the array. As observed in an earlier study, the rearrangements involve either deletion of a locus control region adjacent to the gene array or loss of function via homologous recombination and point mutation. One inactivating mutation, Cys203-to-Arg, was found in 15 probands who carry single genes and in both visual pigment genes in one subject whose array has two genes. This mutation was also found in at least one of the visual pigment genes in 1 subject whose array has multiple genes and in 2 of 321 control subjects, suggesting that preexisting Cys203-to-Arg mutations constitute a reservoir of chromosomes that are predisposed to generate blue-cone-monochromat genotypes by unequal homologous recombination and/or gene conversion. Two other point mutations were identified: (a) Arg247-to-Ter in one subject with a single red-pigment gene and (b) Pro307-to-Leu in one subject with a single 5' red-3' green hybrid gene. The observed heterogeneity of genotypes points to the existence of multiple one- and two-step mutational pathways to blue-cone monochromacy.

Base Sequence↗