von Gontard A, Hillig U, Herold D
Klinik und Poliklinik für Kinder- und Jugendpsychiatrie, Philipps-Universität Marburg.
Z Kinder Jugendpsychiatr. 1992 Jun;20(2):113-20.
The fragile X or Martin-Bell syndrome is the second most common chromosomal cause of mental retardation. It has a prevalence of 1:1000; the clinical and psychopathologic symptoms vary. The difficult diagnosis rests on cytogenetic evidence of the fragile site at Xq 27.3. 18 patients were tested for fragile X syndrome in 4 different laboratories. Of the 32 chromosomal analyses performed 17 were positive and 15 negative. In 11 patients 2 or more analyses were performed in different laboratories for verification. In all 11 cases the findings were discrepant and therefore the initial findings were considered false positive. The clinical and cytogenetic problems are discussed and diagnostic guidelines summarized.
脆性X综合征或马丁-贝尔综合征是导致智力迟钝的第二大常见染色体病因。其患病率为1:1000；临床和精神病理学症状各不相同。诊断困难在于Xq 27.3处脆性位点的细胞遗传学证据。在4个不同实验室对18例患者进行了脆性X综合征检测。在进行的32次染色体分析中，17次为阳性，15次为阴性。对11例患者在不同实验室进行了2次或更多次分析以进行验证。在所有11例病例中，结果存在差异，因此最初的结果被认为是假阳性。文中讨论了临床和细胞遗传学问题并总结了诊断指南。
