1/5. Hydrometrocolpos and polydactyly: a common neonatal presentation of Bardet-Biedl and McKusick-Kaufman syndromes.McKusick-Kaufman syndrome (MKKS) is a rare, recessively inherited syndrome reported mainly in young children and is characterised by vaginal atresia with hydrometrocolpos, postaxial polydactyly, and congenital heart defect. bardet-biedl syndrome (BBS) is the generic name for a genetically heterogeneous group of autosomal recessive disorders characterised by retinal dystrophy or retinitis pigmentosa (appearing usually between 10 and 20 years of age), postaxial polydactyly, obesity, nephropathy, and mental disturbances, or, occasionally, mental retardation. Typically, MKKS is diagnosed (and reported) in very young children, whereas the diagnosis of BBS often is delayed to the teenage years. We report here a series of nine patients diagnosed in infancy with MKKS because of the presence of vaginal atresia and postaxial polydactyly, who later developed obesity and retinal dystrophy, thus turning out to be instances of BBS. The overlap of BBS and MKKS is a real diagnostic pitfall and its importance has to be stressed, for genetic counselling, for clinical management and follow up, and for molecular approaches. The diagnosis of MKKS should be considered with caution in all published cases described exclusively in the neonatal period and in those with mental retardation. We strongly recommend all children seen in infancy with a diagnosis of MKKS to be re-evaluated for RP and other signs of BBS.- - - - - - - - - - ranking = 1keywords = retinal dystrophy, dystrophy (Clic here for more details about this article) |
2/5. bardet-biedl syndrome and cystinuria.An unusual association of bardet-biedl syndrome with cystinuria was described in one patient. A 21-year-old male was admitted to hospital because of renal failure, severe deterioration of visual acuity, polydactyly, brachydactyly, and mental retardation. Laboratory investigations revealed a serum creatinine of 292 mumol/L (3.3 mg/dL) and a GFR of 25 mL/min per 1.73 m2. Quantitative ion exchange chromatography demonstrated an increased urinary excretion rate of cystine, lysine, arginine, and ornithine. The ophthalmologic examination showed a severe atypical retinal dystrophy. visual acuity was severely deteriorated and the patient could only count the examining physician's fingers. The patient had been previously evaluated at the age of 7 years for polyuria, polydipsia, and growth failure. His workup at that time demonstrated nephrogenic diabetes insipidus, normal GFR, and a urinary amino acid pattern consistent with the cystinuric phenotype. There was mental retardation notwithstanding the normal ophthalmologic examination. Intravenous pyelography showed calyceal clubbing, calyceal cysts, and lobulated renal outlines of the fetal type. The patient was evaluated again at the age of 13 years for deterioration of visual acuity and the ophthalmologic examination showed an atypical retinal dystrophy, with sparse pigmentation, central and peripheral atrophy, attenuated vessels, and marked optic disk pallor. To our knowledge the association of bardet-biedl syndrome with cystinuria has never been reported. It is unlikely that cystinuria may have contributed to the kidney damage. The possibility that mental retardation has been induced or aggravated by cystinuria cannot be excluded.- - - - - - - - - - ranking = 1keywords = retinal dystrophy, dystrophy (Clic here for more details about this article) |
3/5. The extra digit. A pointer to the eye?The syndrome associated with an extra digit which is commonly seen by the ophthalmologist is that of Laurence-moon-Biedl, with its well-known association with retinal dystrophy. However, there are several other syndromes in which there is polydactyly and an ocular malformation. Many have colobomata and microphthalmos. Other syndromes show various orbital and eyelid abnormalities, such as ptosis, hypertelorism, and lateral displacement of the canthi. In three syndromes other than the Laurence-moon-Biedl there is a retinal dystrophy. In trisomy 13 there is a severe retinal dysplasia, and in Bloom's syndrome excrescences on Bruch's membrane have been described. There have been several cases of asphyxiating thoracic dystrophy (Jeune's syndrome) described with a retinal dystrophy, and we present a case of the closely-related ellis-van creveld syndrome with a retinal dystrophy. We also present a case with a chromosomal defect (an addition to the short arm of chromosome 2), polydactyly, and a retinal dystrophy.- - - - - - - - - - ranking = 2.5009233725626keywords = retinal dystrophy, dystrophy (Clic here for more details about this article) |
4/5. Clinical pathology and retinal vascular structure in the bardet-biedl syndrome.A comparative study of clinical pathology and retinal vascular structure is described as studied by vascular casting in an eye of a patient with the bardet-biedl syndrome. At the time of examination the eye had been almost blind for at least 4 years. The histopathological examination showed a largely uniform loss of the outer retinal layers. The gross pathological examination of the cast ocular fundus showed three distinct zones, an inner zone inside the temporal vascular arcades where retinal vessels had been cast, a mid peripheral zone with bone spicules, and a peripheral zone with neither cast vessels nor bone spicules. The findings are discussed in relation to possible pathophysiological mechanisms involved in the development of retinal dystrophy in the bardet-biedl syndrome.- - - - - - - - - - ranking = 0.5keywords = retinal dystrophy, dystrophy (Clic here for more details about this article) |
5/5. Abnormal cone synapses in human cone-rod dystrophy.OBJECTIVE: Little is known of the cytopathology of photoreceptors in human inherited retinal dystrophies that initially affect the central retina, including the macula. The current study sought to determine the cytologic features of dysfunctional cone and rod photoreceptors, as well as the pattern of degeneration of the cells in representative cases of central retinal dystrophy. STUDY DESIGN: Comparative human tissue study. MATERIALS: Four human donor eyes with the following forms of central retinal dystrophy: cone-rod dystrophy (CRD), central areolar choroidal dystrophy, bardet-biedl syndrome, and cone dystrophy-cerebellar ataxia. The cytologic features of retinal photoreceptors in these eyes were compared with those in an eye with retinitis pigmentosa and six normal human eyes. methods AND OUTCOME MEASURES: Immunocytochemistry and electron microscopy were used to evaluate the retinal histopathology in the donor eyes. RESULTS: Cone numbers were decreased in the case of CRD, particularly in the central and far peripheral retina, and both cone and rod outer segments were slightly shortened. Occasional degenerate cones had dense cytoplasm and pyknotic nuclei dislocated sclerad to the external-limiting membrane. The most prominent alteration in this retina was marked enlargement and distortion of the cone photoreceptor pedicles, which contained reduced numbers of synaptic vesicles. The retina with central areolar choroidal dystrophy contained a few cones with similarly abnormal synapses. However, comparable cone synapse abnormalities were not observed in the cases of bardet-biedl syndrome, cone dystrophy-cerebellar ataxia, retinitis pigmentosa, or in the normal retinas. CONCLUSIONS: The functional consequences of the cone synapse abnormalities in CRD are not known but may correlate with the electroretinographic abnormalities documented in some cases of CRD. To our knowledge, comparable synapse changes have not been noted in either rods or cones in other forms of retinal dystrophy, including retinitis pigmentosa, suggesting that different cytopathologic mechanisms may be involved.- - - - - - - - - - ranking = 1.5083103530635keywords = retinal dystrophy, dystrophy (Clic here for more details about this article) |