chondroitin-sulfates and Intellectual-Disability

Costello syndrome is a distinctive multiple congenital anomaly syndrome, characterized by loose soft skin with deep palmar and plantar creases, loose joints, distinctive coarse facial features, skeletal abnormalities, cardiac abnormalities (cardiovascular malformation (CVM), hypertrophic cardiomyopathy, tachycardia), predisposition to malignancy, developmental delays, and mental retardation. Previous studies with cultured fibroblasts from individuals with Costello syndrome demonstrate excessive accumulation of chondroitin sulfate-bearing proteoglycans, associated with both impaired formation of elastic fibers and an unusually high rate of cellular proliferation. Despite multiple clinical reports of cardiac abnormalities, there has been only one previously published report describing post-mortem findings in hearts from Costello syndrome patients. Here we provide a detailed description of the post-mortem findings of the hearts of three children with Costello syndrome. Routine histological examination and results of targeted histochemical and immunohistochemical studies revealed that in addition to cardiomyocyte hypertrophy, these hearts also demonstrated massive pericellular and intracellular accumulation of chondroitin sulfate-bearing proteoglycans and a marked reduction of elastic fibers. Normal stroma was replaced by multifocal collagenous fibrosis. Most peculiar was the finding that the bulk of the chondroitin sulfate accumulated in these Costello syndrome hearts is a chondroitin-6-sulfate. In contrast, deposition of chondroitin-4 sulfate was below the level detected in normal hearts. We propose that an imbalance in sulfation of chondroitin sulfate molecules and subsequent accumulation of chondroitin-6-sulfate in cardiomyocytes contribute to the development of the hypertrophic cardiomyopathy of Costello syndrome.

Topics: Abnormalities, Multiple; Cardiomyopathy, Hypertrophic; Child; Child, Preschool; Chondroitin Sulfates; Developmental Disabilities; Face; Fatal Outcome; Humans; Infant; Intellectual Disability; Male; Myocardium; Skin Abnormalities; Syndrome

Systemic findings in a 23-year-old white man with mucolipidosis type IV included early delayed psychomotor development, mental retardation, and mild facial dysplasia. There was urinary excretion of chondroitin sulfate. Ophthalmologic examination showed corneal haze, pigmentary retinopathy, and severe optic atrophy. Light microscopy showed massively engorged superficial and intermediate epithelial cells of both the cornea and the conjunctiva. By transmission electron microscopy these contained fine granular material consistent with acid mucopolysaccharide and concentric lamellar bodies presumably representing phospholipids. This storage phenomenon was also found in macrophages, plasma cells, ciliary epithelial cells, Schwann cells, retinal ganglion cells, and vascular endothelial cells. Light microscopy also disclosed early cataract formation, marked outer retinal degeneration, and optic atrophy.

Topics: Adult; Chondroitin Sulfates; Conjunctiva; Corneal Opacity; Face; Humans; Intellectual Disability; Male; Microscopy, Electron; Mucolipidoses; Optic Atrophy; Psychomotor Disorders; Retinal Degeneration; Retinal Ganglion Cells

A 14-year-old boy was found to excrete excessive amounts of acidic glycosaminoglycans which were predominantly chondroitin 4-sulfate and chondroitin 6-sulfate. Clinical features included dwarfism, mental retardation, coarse facies, deformities of the spine, hip joints and thorax, and granulations in leucocytes. The clinical and biochemical features found in this boy were compared with the known types of mucopolysaccharidosis and it has been concluded that this case is a new type of mucopolysacchariduria.

Topics: Adolescent; Chondroitin; Chondroitin Sulfates; Dwarfism; Glycosaminoglycans; Humans; Intellectual Disability; Male; Mucopolysaccharidoses