title: Female twin with Hunter disease due to nonrandom inactivation of the X-chromosome: a consequence of twinning.
abstract: We report the occurrence of Hunter disease (mucopolysaccharidosis type II) in a karyotypically normal girl who was one of identical twins. Molecular studies showed nonrandom X-inactivation in both her fibroblasts and lymphocytes, while her normal twin showed equal usage of both X chromosomes. In view of previous reports of 7 pairs of identical female twins in which one had Duchenne muscular dystrophy, it seems that twinning may be strongly associated with nonrandom X-inactivation, and is not specific to the properties of the disease causing gene.
authors: Division of Biochemistry and Metabolism, Institute of Child Health, London, U.K.
authors: B
authors: B
authors: Winchester
authors: E
authors: E
authors: Young
authors: S
authors: S
authors: Geddes
authors: S
authors: S
authors: Genet
authors: J
authors: J
authors: Hurst
authors: H
authors: H
authors: Middleton-Price
authors: N
authors: N
authors: Williams
authors: M
authors: M
authors: Webb
authors: A
authors: A
authors: Habel
authors: S
authors: S
authors: Malcolm
mesh_terms: D015342:DNA Probes; D004200:Diseases in Twins / Q000235:genetics*; D004303:Dosage Compensation, Genetic; D005260:Female; D005347:Fibroblasts / Q000648:ultrastructure; D006025:Glycosaminoglycans / Q000378:metabolism; D006579:Heterozygote; D006801:Humans; D007066:Iduronate Sulfatase / Q000235:genetics; D007231:Infant, Newborn; D007962:Leukocytes / Q000648:ultrastructure; D008957:Models, Genetic; D016532:Mucopolysaccharidosis II / Q000196:embryology / Q000235:genetics*; D010375:Pedigree; D014430:Twins, Monozygotic
chemical_list: D015342:DNA Probes; D006025:Glycosaminoglycans; D007066:Iduronate Sulfatase