MPS screening methods, the berry spot and acid turbidity tests, cause a high incidence of false‐negative results in sanfilippo and morquio syndromes

Journal of Clinical Laboratory Analysis - Tập 16 Số 5 - Trang 253-258 - 2002
Chang Chih‐Kuang1, Lin Shuan‐Pei2,1, Lee Shyue‐Jye3, Wang Tuen‐Jen3
1Division of Genetics and Metabolism, Department of Medical Research, MacKay Memorial Hospital, Taipei, Taiwan
2Department of Pediatrics, Mackay Memorial Hospital, Taipei, Taiwan
3Department of Clinical Laboratory, MacKay Memorial Hospital, Taipei, Taiwan

Tóm tắt

AbstractBecause of differences in the types and quantities of glycosaminoglycans (GAGs) in various mucopolysaccharidoses (MPSs), MPS screening tests, including the Berry spot and acid turbidity tests, are not specific or sensitive enough for the preliminary diagnosis of MPS. A false‐negative result is common. We analyzed urine samples collected from 492 patients who were examined for inborn errors of metabolism using the Berry spot and acid turbidity (qualitative and quantitative) tests. Of those, 48 MPS patients (seven with MPS I, 17 with MPS II, nine with MPS III, 11 with MPS IV, and four with MPS VI) underwent preliminary differentiation between MPS types by two‐dimensional electrophoresis (2D‐EP), and were confirmed by enzymatic assay. Approximately 21.0% and 7.1% of the 492 samples showed positive reactions in the Berry spot and acid turbidity tests, respectively. Of these, a total of 35 samples with MPS types I, II, and VI showed strong positive reactions in both tests. Five patients with Sanfilippo (MPS III) and six patients with Morquio (IV) syndromes showed false‐negative results in both tests. In our study, approximately 13.8% (68 in 492 samples) samples showed a positive reaction in the Berry spot test but a negative one in the acid turbidity test, for unknown reasons. The Berry spot and acid turbidity tests are used extensively for the preliminary diagnosis of MPS in Asia; however, the possibility of a misdiagnosis of MPS type III and IV with both tests should be kept in mind. For accurate diagnosis and confirmation of MPS, the 2D‐EP method and enzymatic assay are recommended. They provide high sensitivity, specificity, and efficiency in diagnosing MPS. J. Clin. Lab. Anal. 16:253–258, 2002. © 2002 Wiley‐Liss, Inc.

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Tài liệu tham khảo

Neufeld EF, 1995, The metabolic and molecular bases of inherited disease, 2465

Applegarth DA, 1997, New York. Organelle diseases: clinical features, diagnosis, pathogenesis and management, 45

10.1016/S0957-5839(97)80195-9

10.1016/S0957-5839(96)80065-0

Berry HK, 1960, A paper spot test useful in study of Hurler's syndrome, J Lab Clin Med, 55, 136

10.1016/S0009-9120(87)80088-7

10.1016/0009-8981(85)90318-3

Rezvani I, 1973, Evaluation of screening tests for urinary mucopolysaccharides, Pediatrics, 52, 64, 10.1542/peds.52.1.64

de Jong JG, 1989, Dimethylmethylene blue‐based spectrophotometry of glycos‐aminoglycans in untreated urine: a rapid screening procedure for mucopolysaccharidoses, Clin Chem, 35, 1472, 10.1093/clinchem/35.7.1472

10.1016/0003-2697(82)90674-1

Dembure PP, 1991, Techniques in diagnostic human biochemical genetics—a laboratory manual, 77

Berman ER, 1971, A reliable spot test for mucopolysaccharidoses, Clin Chem, 17, 886, 10.1093/clinchem/17.9.886

de Jong JG, 1991, The spot test is not a reliable screening procedure for mucopolysaccharidoses, Clin Chem, 37, 572, 10.1093/clinchem/37.4.572

10.1177/000456329002700208

Chuang CK, 2001, Diagnostic screening for mucopolysaccharidoses by the dimethylmethylene blue method and two dimensional electrophoresis, Chinese Med J (Taipei)(Taipei), 64, 15

10.1023/A:1012763026526

10.1007/BF01799255

10.1111/j.1399-0004.1985.tb00217.x

10.1016/0009-8981(90)90339-T

10.1016/S0022-3476(68)80071-X

10.1136/jcp.41.9.936

10.1002/pd.1970020305

10.1002/(SICI)1097-0223(199609)16:9<829::AID-PD953>3.0.CO;2-H

10.1002/(SICI)1097-0223(200003)20:3<183::AID-PD774>3.0.CO;2-J

Li P, 1999, Molecular basis of iduronate‐2‐sulphatase gene mutations in patients with mucopolysaccharidosis type II (Hunter syndrome), J Med Genet, 36, 21

10.1136/adc.79.3.237

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Journal of Clinical Laboratory Analysis

Tập 16 Số 5

253-258

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