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Biomedical subjects

A M Bardelli

Publications and source records attributed to A M Bardelli.

At least 19 recordsLinked to original sources
PubMed2001

Pseudoxanthoma elasticum: Point mutations in the ABCC6 gene and a large deletion including also ABCC1 and MYH11.

Pseudoxanthoma elasticum (PXE) is a mendelian disorder characterized by calcification of elastic fibers in skin, arteries, and retina. It results in dermal lesions, arterial insufficiency and retinal hemorrhages, leading to macular degeneration. PXE is transmitted either as an autosomal dominant or recessive trait and several sporadic cases have been observed. Mutations in the ABCC6 gene have been identified very recently in patients. Here, we report on a large Italian family affected by pseudoxanthoma elasticum for which linkage analysis had pointed to a region encompassing markers D16S3069-D16S405-D16S3103; hemizygosity of marker D16S405 allowed us to detect a submicroscopic deletion of at least 900 kb involving ABCC6, ABCC1, and MYH11. Mutation analysis on the other allele of the family, as well as on two additional sporadic cases, revealed nonsense (Y227X, R518X, R1164X) and frame-shift (c.960delC) mutations in ABCC6 (MRP6) further confirming the role of this multi-drug resistance gene in the etiology of pseudoxanthoma elasticum. Furthermore, clinical re-examination of members of the family harboring the deletion led to the detection of additional features, potentially caused by the deletion of the MYH11 gene. In the course of the analysis five nonpathogenic variants were found in ABCC6: 1233T>C, 1245G>A, 1838 T>G (V614A), 1890C>G, and 3506+83C>A. Hum Mutat 18:85, 2001.

Adult↗
PubMed2001

PAX6 mutation in a family with aniridia, congenital ptosis, and mental retardation.

Congenital aniridia is due to deletions and point mutations in the PAX6 gene. We describe here a case of a mother and her two sons with a syndrome comprising congenital aniridia, ptosis, and slight mental retardation. The sons also show behavioral changes. The possibility of deletion around the PAX6 locus was excluded by polymorphism studies and fluorescence in situ hybridization analysis. Mutation screening of the PAX6 gene revealed the presence of a transversion C719A, resulting in the substitution of arginine for serine at residue 119. We suggest that this missense mutation is responsible both for aniridia and ptosis, and possibly also for the observed cognitive dysfunction in this family.

Abnormalities, Multiple↗
PubMed2001

Coats disease: smaller volume of the affected globe.

PURPOSE: To determine whether a significant smaller volume of the affected globe, compared with that of the normal globe, is an additional feature of Coats disease. MATERIALS AND METHODS: Ocular globe volume was assessed in 13 children (11 boys, two girls; age range, 0.6-14 years; mean age, 4.1 years) with Coats disease and in 18 (eight boys, 10 girls; age range, 0.5-12 years; mean age, 3.6 years) with unilateral retinoblastoma. Orbital computed tomographic scans were available for all children; magnetic resonance images were available for 11 children-seven with Coats disease and four with retinoblastoma. For volume estimation, anteroposterior and equatorial diameters of ocular globes were measured. Statistical analysis was conducted with univariate and multivariate methods. RESULTS: In children with Coats disease, the mean volume of the affected globe was 4,877.03 mm(3) (range, 2,951.47-6,284.70 mm(3)) and that of the normal globe, 6,018.00 mm(3) (range, 4,062.32-7,509.26 mm(3)). In children with retinoblastoma, the mean volume of the affected globe was 4,557.06 mm(3) (range, 1,612.01-7,463.00 mm(3)) and that of the normal globe, 4,402.11 mm(3) (range, 1,360.46- 7,463.00 mm(3)). The Coats disease population had a significantly smaller volume of the affected globe (z = -3.1009; P =.002); the retinoblastoma population did not have a statistically significant trend toward a bigger affected globe volume (z = -1.7064; P =.088). The difference between the affected globe volume and the normal globe volume in children with Coats disease was the only significant independent variable (P =.005). CONCLUSION: A significantly smaller volume of the affected globe is an additional feature of Coats disease.

Adolescent↗
PubMed1999

MRI of Wolfram syndrome (DIDMOAD).

Wolfram syndrome (DIDMOAD) is a rare diffuse neurodegenerative disorder characterised by diabetes insipidus, diabetes mellitus, optic atrophy, deafness, and a wide variety of abnormalities of the central nervous system, urinary tract and endocrine glands. It may be familial or sporadic. Reported features on MRI of the brain are absence of the physiological high signal of the posterior lobe of the pituitary, shrinkage of optic nerves, chiasm and tracts, atrophy of the hypothalamic region, brain stem, cerebellum, and cerebral cortex. We report a 12-year-old girl with a 5-year history without brain stem, cerebellar or cerebral atrophy. MRI showed an unusual feature: a focus of high signal on PD- and T2-weighted images in the right substantia nigra. This is consistent with previously reported neuropathological post-mortem studies, but has never been reported in vivo.

Atrophy↗
PubMed1998

Schnyder corneal crystalline dystrophy: description of a new family with evidence of abnormal lipid storage in skin fibroblasts.

Schnyder corneal crystalline dystrophy (SCCD) comprises corneal opacities often associated with precocious arcus senilis and genua valga. The metabolic defect seems to be related to abnormal lipid storage in the central part of the cornea, especially the anterior stroma, consisting mainly of nonesterified cholesterol. Plasma lipid levels are not always increased suggesting that the disease may be due to abnormal lipid metabolism limited to the cornea. We observed a family with typical SCCD, in 1 case associated with mental retardation and mild cerebellar hypoplasia. Results of serum lipid analysis of all patients were normal. Ultrastructural study of a skin biopsy specimen and fibroblast pellet showed membrane-bound spherical vacuoles containing lipid material. Cultured fibroblasts stained by filipin, a fluorescent probe that specifically binds unesterified cholesterol, showed abnormal cytoplasmic fluorescent material, suggesting abnormal cholesterol metabolism. The presence of neurological impairment, associated with SCCD in 1 of our cases, may be regarded as coincidental. Evidence of storage lipids in skin and cultured fibroblasts suggests that the disorder of intracellular cholesterol metabolism is not limited to the cornea and that skin biopsy may be a useful method to confirm the diagnosis.

Adult↗
PubMed1989

Retinoblastoma. Analysis of 75 cases and proposal for a new model of oncogenesis and tumor growth kinetics.

A series of 75 retinoblastoma patients were analyzed at the Institute of Ophthalmology, Siena, and a mathematical model for the 'nodule to cancer' transformation applied to it. The authors obtained data in disagreement with Knudson's 'two hit' hypothesis but fitting an alternative model of oncogenesis. This model is based on probabilistic arguments and a possible pattern of tumor growth and evolution is given in detail.

Adolescent↗
PubMed1989

Buphthalmos and progressive elephantiasis in neurofibromatosis. A report of three cases.

Two cases of buphthalmos and regional gigantism in peripheral neurofibromatosis (Von Recklinghausen disease) are described. The ocular hypertension was detected at birth and thereafter the facial hemihypertrophy, café-au-lait spots and neurofibromas. One case presented a progressive facial elephantiasis without buphthalmos. The evolution in neurofibromatous elephantiasis of these three cases is discussed.

Child↗
PubMed1989

Congenital and developmental cataracts and multimalformation syndromes.

Cataracts are often found in association with many systemic disorders. Some are congenital in origin but in other cases they develop in early infancy or later in life. They are found in association with disorders, connective tissue disorders, neurological conditions, chromosomal abnormalities and dermatological disorders. Some of these syndromes have a genetic basis but often it is uncertain whether they are hereditary and often their cause is unknown.

Abnormalities, Multiple↗
PubMed1987

Normal rhodanese activity in leukocytes from Leber patients: enzyme characterization and activity levels.

The thiosulfate:cyanide sulfurtransferase (rhodanese) enzyme (EC 2.8.1.1.) was studied in human leukocytes from control subjects and from nine patients with Leber's hereditary optic atrophy. Enzyme activity was proportional to protein concentration in the tested range (0.09 to 0.39 mg) as well as to incubation time. The optimal pH for reaction was 8.7 and the apparent Km for thiosulfate was 7 X 10(-3) M. No significant difference of enzyme activity was present in Leber's disease.

Female↗
PubMed1985

Atypical phenotype of Refsum's disease: clinical, biochemical, neurophysiological and pathological study.

The authors describe the clinical, biochemical, electrophysiological and ultrastructural study of a case of Refsum's disease whose phenotype suggested other hereditary ataxias. Due to the presence of Babinski sign and optic atrophy and the absence of retinitis pigmentosa, this case can be considered atypical. Electrophysiological and ultrastructural findings confirm the variability of peripheral lesions in this hereditary polyneuropathy.

Adolescent↗
PubMed1985

Leber's optic neuritis.

The authors give a résumé of the main clinical characteristics of Leber's disease with presentation of pedigrees of three affected families.

Adolescent↗