mucolipidosis

Any of a group of lysosomal storage diseases in which symptoms of visceral and mesenchymal mucopolysaccharide, glycoprotein, oligosaccharide, or glycolipid storage are present; clinically, they bear a superficial resemblance to the mucopolysaccharidoses; autosomal recessive inheritance. [muco- + lipid + -osis, condition]

- m. I [MIM*256550] m. somewhat like a mild form of Hurler syndrome with coarse facial features, macular cherry red spots, myoclonus epilepsy, mild dysostosis multiplex, and moderate mental retardation due to neuraminidase deficiency; autosomal recessive inheritance caused by mutation in the neuraminidase gene (NEU) on 6p. SYN: lipomucopolysaccharidosis.

- m. II [MIM*252500] a metabolic disorder with onset in early childhood characterized by clinical and radiographic findings similar to those in Hurler syndrome including gum hypertrophy, thoracic dysplasia, congenital hip dislocation, and mental retardation; vacuolated lymphocytes and unusual inclusion bodies in cultured fibroblasts (I-cells) are found; lysosomal enzymes are increased in serum, spinal fluid, and urine; urinary mucopolysaccharides are normal; associated with a deficiency of N-acetylglucosaminyl-1-phosphotransferase; autosomal recessive inheritance. SYN: I-cell disease, inclusion cell disease.

- m. III [MIM*252600] m. with mild Hurlerlike symptoms, restricted joint mobility, short stature, mild mental retardation, and dysplastic skeletal changes, especially of the hip; aortic and mitral valve disease are often present; associated with a deficiency of N-acetyl-α-glucosaminidase or other enzyme deficiencies such as lysosomal enzyme N-acetylglucosaminyl-1-phosphotransferase in mutant fibroblasts lacks the ability to recognize lysosomal enzymes and specific substrates for phosphorylation; autosomal recessive inheritance. SYN: pseudo-Hurler polydystrophy, pseudopolydystrophy.

- m. IV [MIM*252650] psychomotor retardation with cloudy corneas and retinal degeneration, with inclusion cells in cultured fibroblasts; the pathogenesis is uncertain; autosomal recessive inheritance.

* * *

mu·co·lip·i·do·sis .myü-kō-.lip-ə-'dō-səs n, pl -do·ses -.sēz any of several metabolic disorders that are marked by the accumulation of glycosaminoglycans and lipids in tissues and by lysosomal enzymes which are produced in deficient amounts or which fail to be incorporated into lysosomes, that are inherited as autosomal recessive traits, and that have characteristics (as mental retardation) resembling Hurler's syndrome

* * *

mu·co·lip·i·do·sis (mu″ko-lip″ĭ-doґsis) pl. mucolipidoґses. any of a group of lysosomal storage diseases in which both glycosaminoglycans (mucopolysaccharides) and lipids accumulate in tissues but without excess of glycosaminoglycans in the urine.