Genetic heterogeneity of FG syndrome: a fourth locus (FGS4) maps to Xp11.4-p11.3 in an Italian family
Genetic heterogeneity of FG syndrome: a fourth locus (FGS4) maps to Xp11.4-p11.3 in an Italian family
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DOI：
10.1007/s00439-002-0863-7
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发表时间：
2003-02-01
期刊：
影响因子：
5.3
通讯作者：
Nigro, V
中科院分区：
文献类型：
--
作者：
Piluso, G;Carella, M;Nigro, V
FG综合征（FGS, MIM 305450）是一种罕见的x连锁隐性疾病，包括智力迟钝和多种畸形。到目前为止，已经描述了各种家庭，增加了我们对表型变异性的了解，并使临床诊断变得复杂，特别是在散发性患者中。FG综合征的第一个位点（FGS1）与染色体区域Xq12-q21.31相连，但其他家族已被排除在该位点之外。通过对一名患病男孩及其智障舅舅的X染色体倒位[inv(X)(q11q28)]的分析，证实了FG综合征的遗传异质性，提示FG综合征的另一个位点（FGS2, MIM 300321）位于Xq11或Xq28。最近，第三个位点（FGS3）被定位到Xp22.3。我们已经确定并临床表征了一个意大利FG家族，包括31名成员，两代中有三名受影响的男性和两名专性携带者。我们已经排除了已知FGS位点的连锁，而对整个X染色体的广泛研究已经产生了最大LOD分数（Z(max)）为2.66（重组分数=0），在DXS8113和sWXD805之间的标记。这个FG综合征的新位点对应于X染色体上约4.6 Mb的区域。
FG syndrome (FGS, MIM 305450) is a rare X-linked recessive disorder comprising mental retardation and multiple malformations. Various families have been described to date, increasing our knowledge of the phenotype variability and making the clinical diagnosis complex, especially in sporadic patients. The first locus for FG syndrome (FGS1) was linked to chromosome region Xq12-q21.31, but other families have been excluded from this locus. The genetic heterogeneity of FG syndrome has been confirmed by analysis of an X chromosome inversion [inv(X)(q11q28)] in an affected boy and in his mentally retarded maternal uncle, suggesting that an additional locus for FG syndrome (FGS2, MIM 300321) is located at either Xq11 or Xq28. Recently, a third locus (FGS3) has been mapped to Xp22.3. We have identified and clinically characterized an Italian FG family, including 31 members with three affected males in two generations and two obligate carriers. We have excluded linkage to known FGS loci, whereas an extensive study of the whole X chromosome has yielded a maximum LOD score (Z(max)) of 2.66 (recombination fraction=0) for markers between DXS8113 and sWXD805. This new locus for FG syndrome corresponds to a region of approximately 4.6 Mb on the X chromosome.