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K W Small

Publications and source records attributed to K W Small.

At least 37 records · Page 2Linked to original sources
PubMed1996

Ocular motility in North Carolina autosomal dominant ataxia.

The term "vestibulocerebellar ataxia" has been applied to a rare, autosomal dominant, late-onset disease with unusual ocular motility findings. We examined the ocular motility of 18 family members from two different kindreds and found 11 affected individuals. Both families in the present study, one of which was originally described by Farmer and Mustian, as well as the family reported by Farris et al., originated from Johnston County, North Carolina. We suspect that all three of these families have a common ancestral origin. The age of onset of the disorder was 31-60 years in the individuals examined. Ataxia, vertigo, diplopia, oscillopsia, and tinnitus were common complaints. Although a variety of eye movement abnormalities have previously been described in this disease, the most prominent and consistent findings in our patients were (a) abnormal smooth pursuits, (b) inability to suppress the vestibuloocular reflex (VOR), and (c) gaze-evoked nystagmus. These findings suggest that the cerebellar flocculus may be the primary site of pathology.

Adult↗
PubMed1995

Blepharophimosis syndrome is linked to chromosome 3q.

Blepharophimosis syndrome (BPES, blepharophimosis eyelid syndrome) is a distinctive congenital eyelid malformation which can occur sporadically or be inherited in an autosomal dominant fashion. Previous reports have described associated cytogenetic abnormalities on chromosome 3q. We have ascertained and sampled two BPES families with apparent autosomal dominant inheritance and have tested for linkage with 17 polymorphic markers on 3q. Multipoint analysis generated a maximum LOD score of 3.23 using the markers RHO, ACPP and D3S1238. No evidence of genetic heterogeneity was observed. These studies provide the first non-cytogenetic evidence that a defective gene responsible for BPES is located on 3q22.

Blepharophimosis↗
PubMed1994

Pyogenic granuloma of the cornea induced by "snake oil".

A pyogenic granuloma of the cornea developed on the vascularized cornea of a 79-year-old woman after "snake oil" accidentally dripped in her eye. The snake oil was being used to relieve forehead pain, which may have been referred. The five previously reported examples of corneal pyogenic granuloma are similar to this case in that trauma preceded development of the lesion. However, the chemical trauma induced by the snake oil appears to be a unique mechanism of injury.

Aged↗
PubMed1994

Glaucoma after surgery on the retina and vitreous.

Increased intraocular pressure after retinal detachment or its surgery may be addressed in an effective manner, because the clinical setting invariably suggests an ascertainable etiologic mechanism. Directed, stepwise therapy may then be instituted promptly to minimize lasting or functional impairment from long-standing increased intraocular pressure.

Glaucoma↗
PubMed1994

Application of molecular genetics to ocular diseases.

With the new advances in molecular genetic technologies and methods has come great progress in mapping disease-causing genes. Many of these methods using polymerase chain reaction have made gene mapping much more efficient and effective. Herein is a brief review of some of the most recent advances in mapping genes causing eye diseases. Despite the technological advances, none of this progress would have been made had not the families been available for studies. Therefore, the clinician is the cornerstone of, essentially, all molecular genetic studies and it is imperative for the clinician to be aware of these diseases and the importance of ascertaining families with these disorders to continue such progress.

Chromosome Mapping↗
PubMed1993

Genetic and physical map of 11 short tandem repeat polymorphisms on human chromosome 6.

A linkage map of 11 short tandem repeat polymorphisms was constructed for human chromosome 6. The order from p to qter was F13A1-D6S105-D6S254-D6S251-D6S252-D6S24 9-(ARG1-D6S87)-D6S250-D6S255-D6S253. For the region spanned by the 6q markers, the male map distance was less than half the female map distance (58 and 126.3 cM, respectively). Two-point linkage analysis was also used to position the markers relative to markers in the CEPH public database. Physical mapping of these markers was completed using a somatic cell hybrid panel that contained varying segments of chromosome 6. Two of the markers mapped to the short arm of chromosome 6; the remainder were spaced over 86.5 cM of the long arm from 6q13 to 6qter. The linkage and physical maps were completely consistent.

Base Sequence↗
PubMed1993

Genetic mapping of dinucleotide repeat polymorphisms and von Hippel-Lindau disease on chromosome 3p25-26.

A genetic map of highly polymorphic microsatellite markers spanning the von Hippel-Lindau region (VHL) of 3p25 was constructed using the CEPH reference pedigrees. A greater than 1000:1 odds map of pter-D3S1038-RAF1-D3S651-D3S656-D3S110- D3S1255-cen was found. Genotyping of six multigenerational VHL families showed the region surrounding the D3S1038 marker to be the most likely location for the VHL gene with a peak location score of 10.04 with VHL completely linked to D3S1038. These data provide an initial high resolution genetic map of this region; D3S1038 appears to be a highly polymorphic marker that should prove useful in the future for presymptomatic diagnosis.

Adult↗
PubMed1993

North Carolina macular dystrophy (MCDR1). A review and refined mapping to 6q14-q16.2.

The macular degenerations comprise a heterogeneous group of diseases, generally reported in small families. Single, large family studies of North Carolina macular dystrophy have aided in defining the spectrum of the phenotype of this disorder and its relationship to other macular degenerations. North Carolina macular dystrophy has many phenotypic similarities to age-related macular degeneration with the glaring exception of the early age of onset of North Carolina macular dystrophy. The authors initially reported mapping this disease by linkage to the long arm of chromosome 6. They now report additional data on a total of 247 individuals in the original North Carolina macular dystrophy family whom we ascertained for clinical and molecular genetic studies. Standard clinical ophthalmic examination revealed that 96 of these individuals were affected. Molecular genetic studies increased the LOD score to 23 and refined the genomic localization of the disease-causing gene to 6q14-q16.2.

Adult↗
PubMed1993

Pigmented paravenous retinochoroidal atrophy (PPRCA) with optic disc drusen.

Pigmented paravenous retinochoroidal atrophy (PPRCA) is a rare retinal disorder which is diagnosed primarily on its typical funduscopic appearance of retinal pigment epithelial atrophy and clumping in a paravenous distribution. Pigmented paravenous retinochoroidal atrophy is usually asymptomatic and seldom causes marked decrease in visual acuity or significant impairment of electrophysiologic functions. Optic nerve head drusen, which are thought to be inherited as an autosomal dominant trait, rare in blacks, and known to be associated with retinitis pigmentosa, have not been previously reported with PPRCA. The authors present a case of PPRCA which is classic except for an additional finding of optic nerve head drusen. The heritability of PPRCA remains controversial but the authors' reported association of PPRCA and disc drusen seems to suggest some genetic influence.

Atrophy↗
PubMed1992

North Carolina macular dystrophy and central areolar pigment epithelial dystrophy. One family, one disease.

The autosomal-dominant macular dystrophies known as North Carolina macular dystrophy and central areolar pigment epithelial dystrophy were originally described as distinct disease entities in three separate families. However, these disorders have several phenotypic features in common. The single large family with North Carolina macular dystrophy, which descended from three Irish brothers in 1790, has undergone extensive genealogic studies expanding the kindred to more than 2000 family members. As a result, two previously described families with central areolar pigment epithelial dystrophy have been found to descend from these same three Irish brothers with North Carolina macular dystrophy and, therefore, also have North Carolina macular dystrophy. This helps simplify the nosology of the disease and expands the phenotype of North Carolina macular dystrophy to include choroidal neovascular membranes.

Child↗
PubMed1992

North Carolina macular dystrophy is assigned to chromosome 6.

North Carolina macular dystrophy (NCMD) is an autosomal dominant macular dystrophy causing impaired central vision at an early age, is completely penetrant, and is present in a single large family. With the development of the hypervariable microsatellite (CA repeats) markers in the human genome, it was possible to relatively rapidly screen most of the genome for linkage to the NCMD gene. After utilizing 124 genetic markers, which excluded over 95% of the human genome, three Marshfield microsatellites located at 6q13-q21 were linked to the NCMD locus. Marshfield marker (MFD) 131 gave a lod score of Z(theta) = 4.36 at theta = 0.137; MFD 171 gave a Z(theta) = 8.42 at theta = 0.004; and MFD 97 gave a Z(theta) = 13.10 at theta = 0.017. Other retinal diseases have been reported on 6q stressing the importance of this region and possibly suggesting that these diseases may be allelic or located in part of a large macular gene family. Locating and characterizing the NCMD gene may be an important step in understanding this group of maculopathies as well as age-related macular degeneration (AMD), a common cause of blindness in the elderly.

Adult↗
PubMed1992

Linkage of Rieger syndrome to the region of the epidermal growth factor gene on chromosome 4.

Rieger syndrome is an autosomal dominant disorder of morphogenesis in which previous cytogenetic arrangements have suggested chromosome 4 as a candidate chromosome. Using a group of highly polymorphic short tandem repeat polymorphisms (STRP), including a new tetranucleotide repeat for epidermal growth factor (EGF), significant linkage of Rieger syndrome to 4q markers has been identified. Tight linkage to EGF supports its role as a candidate gene, although a recombinant in an unaffected individual has been identified. This study demonstrates the utility of using polymorphic STRP markers when only a limited number of small families are available for study.

Abnormalities, Multiple↗
PubMed1992

A clinicopathological study of ocular involvement in primary hyperoxaluria type I.

We performed a clinicopathological study on the eyes of a 3-year-old girl with primary hyperoxaluria type I. An examination one year before death disclosed a slightly diminished visual acuity in both eyes with black, geographic central macular, subretinal patches. Calcium oxalate was deposited predominantly in the retinal pigment epithelium of the posterior pole, where these cells were markedly hyperplastic and hypertrophied round foci of oxalate crystals. Oxalate crystals were exceedingly sparse in other ocular structures and when present were not associated with an apparent tissue reaction in these other locations. A collagenous layer was evident between parts of the retinal pigment epithelium and the neurosensory retina, which contained occasional perivascular clumps of melanin laden cells. The predominant deposition of oxalate in the retinal pigment epithelium, with the exuberant response of these cells around the crystals, gives a clue to the pathogenic mechanisms of primary hyperoxaluria.

Calcium Oxalate↗