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Biomedical subjects

J W Delleman

Publications and source records attributed to J W Delleman.

At least 19 recordsLinked to original sources

Mental retardation in amaurosis congenita of Leber.

A group of 229 patients with Leber's congenital amaurosis (ACL) was investigated for associated defects. We especially looked for the occurrence of mental retardation because the literature gives varying frequencies for this association. A percentage of 19.8% was found. This finding has consequences for genetic counseling. Special attention was given to how frequently sibling pairs occurred in which one patient was mentally retarded whereas the other functioned normally. We found 11 sibling pairs that were discordant with regard to their mental state. This observation proves that mental retardation could be one variable expression of ACL.

Abnormalities, Multiple↗

DNA carrier detection in X-linked progressive cone dystrophy.

X-linked progressive cone dystrophy (XLPCD) is characterized by progressive macular atrophy, abnormal colour vision, reduced cone responses in ERG, and reduced visual acuity. XLPCD may be genetically heterogeneous. Therefore, carrier detections by DNA analysis may only be carried out in those families in which the position of the gene locus can be clearly established. Here, we describe the first DNA carrier detections in XLPCD.

DNA↗

Goniodysgenesis in familial primary open-angle glaucoma.

Results of a pilot study to evaluate goniodysgenesis as a cause of familial open-angle glaucoma are reported. Patients with a familial high tension open-angle glaucoma and a goniodysgenetic chamber angle (n = 11), a number of their relatives with glaucoma (n = 12), and their relatives without glaucoma (n = 26) were compared to a group of normals (n = 120). Eight characteristics of goniodysgenesis were scored and summed into a total goniodysgenesis-score for each chamber angle examined, a higher score corresponding to a more dysgenetic chamber angle. The distribution of the goniodysgenesis-score was compared between the four groups studied. A highly significant difference (p < 0.001) was found between the probands and the normal population, but there was no difference in distribution between the relatives with glaucoma and the relatives without glaucoma. It is concluded that goniodysgenesis cannot explain the occurrence of glaucoma in the families investigated in this study. A significant difference was also found between the normal population and all the relatives combined, with higher scores in the group of relatives. An explanation could be that goniodysgenesis is inherited within the families studied, possibly in an autosomal dominant way, but independent of the occurrence of glaucoma.

Adult↗

Biometry in X linked megalocornea: pathognomonic findings.

Biometric study in a series of 11 affected males provides characteristic findings. The patients present with a large cornea with short radius, very deep anterior chamber depth (AC depth) exceeding the normal mean value of plus 2 SD, and a short vitreous length. Calculation of the postlimbal depth, a method applied in this study to obtain information about positioning of the iris and the lens, reveals a posterior positioning of the iris and lens. The posterior positioning of the iris and lens was proved to occur at the expense of the vitreous. The importance of biometric data for diagnosis and for differential diagnosis in primary infantile glaucoma and other diseases with megalocornea is discussed.

Adolescent↗

X linked progressive cone dystrophy. Localisation of the gene locus to Xp21-p11.1 by linkage analysis.

Six affected males, three female carriers, and two possible carriers were evaluated from a three generation pedigree with X linked progressive cone dystrophy. The affected males presented with progressive decrease of visual acuity, impairment of colour vision, and deterioration of electroretinogram, which ranged from absent response to red light in all young patients to abnormal cone-rod responses in the elderly ones. In most affected males dark adaptation curves were monophasic and the electro-oculogram values were reduced. While some obligate carriers showed functional anomalies, they all had reduced electroretinogram response to red light. The a1/aT ratio for 1 joule white light was an appropriate indicator for carrier state. The family was studied with seven DNA markers from the proximal part of the short arm of the human X chromosome. So far, significant linkage has been found between three DNA markers and COD1, which assigns the progressive cone dystrophy gene (COD1) in this family to Xp21-p11.1. Differential diagnosis with congenital cone dystrophies is discussed.

Adult↗

The intraocular straylight function in some hereditary corneal dystrophies.

The direct compensation method allows for an accurate determination of intraocular light scattering between 3.5 and 25 degrees of scattering angle and is suitable for untrained subjects. The method was used to study light scattering in four forms of hereditary corneal dystrophies. Light scattering is the basis of glare complaints and was compared with visual acuity loss. The findings corresponded to the complaint patterns: in central crystalline dystrophy light scattering can be much increased with relatively well preserved visual acuity. In posterior polymorphous dystrophy the reverse is true. In macular dystrophy (Groenouw II) and lattice dystrophy the situation is more or less intermediate between these two extremes.

Adolescent↗

Autosomal dominant congenital miosis with megalocornea.

A family with AD congenital miosis is presented. The ocular symptoms were: megalocornea, iris translucency, microcoria with poor pupillary dilatation and goniodysgenesis with anterior insertion of the iris. This observation confirms that in congenital miosis abnormal development of the whole anterior eye segment may occur. The patients have an increased risk to develop glaucoma. If retinoscopy is impossible due to pin-point pupils, ultrasonic biometry to determine the axial length is recommended. An optical iridectomy could improve visual performance at low illumination; the complaints of photophobia, which are related to the iris translucency, persist.

Adolescent↗

X-linked megalocornea. Ocular findings and linkage analysis.

A family with X-linked megalocornea (XMC) is presented. The most typical ocular features of the disease (cornea globosa, arcus lipoides, mosaic dystrophy of the cornea, pigment dispersion, and cataract) are described and their diagnostic value is discussed by reviewing the literature. Linkage data suggest that the XMC locus maps in the region Xq13-q25, most probably in Xq21-q22.

Adult↗

Crystalline cataract and uncombable hair. Ultrastructural and biochemical findings.

A 7-year-old girl was found to have a progressive axial crystalline cataract located in the embryonal, fetal, and infantile nucleus. She also had the unknown association of crystalline cataract with uncombable hair. Samples of the aspirate after extracapsular cataract extraction (ECCE) showed elongated, trigonal crystals on scanning electron microscopy. On transmission electron microscopy, the crystals were surrounded by a membrane sometimes consisting of up to 30 concentric layers. The crystals were found to contain carbon, oxygen, nitrogen, sulfur, and disulfide bonds. The findings suggest that a major constituent of the crystals was a sulfur-containing aminoacid, probably cystine. Protein analysis of the remaining lens material showed elevated alpha-, beta 2-, and gamma 2- crystallin levels. Analysis of the hair root status showed hair loss in the resting phase of the hair cycle with abnormal sheathing in most hairs that were in the growth phase.

Cataract↗

ICE syndrome.

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Cheek↗

Familial grouped pigmentation of the retinal pigment epithelium.

Grouped pigmentation of the retinal pigment epithelium was found in a father and his son. They had a normal resting potential on the electro-oculogram, but the son had a lower normal light rise. We believe this is the first description of familial grouped pigmentation.

Child↗

Are Lisch nodules an ocular marker of the neurofibromatosis gene in otherwise unaffected family members?

A male patient with classical neurofibromatosis is reported. Examination of the other family members revealed 2 patients with solitary cutaneous neurofibromas and 2 with one or more Lisch nodules without other cutaneous or systemic signs of neurofibromatosis. This suggests that Lisch nodules can be a marker for the neurofibromatosis gene in otherwise unaffected family members.

Adult↗

Meesmann's epithelial dystrophy of the cornea. Biometrics and a hypothesis.

Corneal thickness in the affected members of 3 families with Meesmann's epithelial dystrophy was statistically significantly less than that of the nonaffected members and of their controls. From our data one could speculate that the stroma rather than the epithelium is the primary source of the dystrophy. The thinner the cornea, the more marked the expression of the epitheliopathy. The affected members of the 2 families that were large enough for a separate analysis showed a marked difference in expressivity of the epithelial disorder. In one family the epitheliopathy showed a stationary character, while in the other there was a progression in the density of the epithelial vesicles.

Cornea↗

Genetic diseases caused by peroxisomal dysfunction. New findings in clinical and biochemical studies.

Peroxisomes play an essential role in human cellular metabolism. Peroxisomal disorders, a group of genetic diseases caused by peroxisomal dysfunction, can be classified in three groups namely a group of disorders with a general peroxisomal dysfunction (Zellweger syndrome; infantile type of Refsum's disease; neonatal adrenoleukodystrophy, hyperpipecolic acidemia), a group with an impairment of some, but not all peroxisomal functions (rhizomelic chondrodysplasia punctata) and a group with impairment of only a single peroxisomal function (acatalasemia, X-linked adrenoleukodystrophy/adrenomyeloneuropathy; adult type of Refsum's disease; peroxisomal thiolase deficiency; peroxisomal acyl-CoA oxidase deficiency; hyperoxaluria type I). In this paper we report the typical findings in ophthalmological examinations of patients suspected of Zellweger syndrome contributing to the clinical diagnosis of this disorder. In biochemical studies using a rapid gaschromatographic detection method for plasmalogens we confirmed that plasmalogens are severely deficient in all tissues of Zellweger patients studied. Moreover, using a recently developed radiochemical method, de novo plasmalogen biosynthesis was found to be impaired in fibroblasts from patients with Zellweger syndrome, infantile Refsum's disease, neonatal adrenoleukodystrophy or rhizomelic chondrodysplasia punctata, this in contrast to X-linked chondrodysplasia in which a normal plasmalogen biosynthesis was found. From the literature it is known that peroxisomal beta-oxidation with both long-chain (C16:0) and very long-chain (C24:0; C26:0) fatty acids is deficient in Zellweger syndrome, infantile Refsum's disease and neonatal adrenoleukodystrophy. In contrast, in X-linked adrenoleukodystrophy only the peroxisomal beta-oxidation of the very long chain fatty acids is impaired. As a result very long-chain fatty acids accumulate in tissues, plasma, fibroblasts and amniotic fluid cells from patients with Zellweger syndrome, infantile Refsum's disease, neonatal and X-linked adrenoleukodystrophy, but not in rhizomelic chondrodysplasia punctata or X-linked chondrodysplasia. Finally we confirmed that the peroxisomal enzyme alanine glyoxylate aminotransferase is severely deficient in liver from a patient that died because of the neonatal type of hyperoxaluria type I, but not in liver from Zellweger patients.

Chromatography, Gas↗