Clinical and molecular genetic characterization of two siblings with trisomy 2p24.3-pter and monosomy 5p14.3-pter
Clinical and molecular genetic characterization of two siblings with trisomy 2p24.3-pter and monosomy 5p14.3-pter
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DOI：
10.1002/ajmg.a.38313
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发表时间：
2017-08-01
影响因子：
2
通讯作者：
Wakamatsu, Nobuaki
中科院分区：
文献类型：
--
作者：
Fukushi, Daisuke;Kurosawa, Kenji;Wakamatsu, Nobuaki
部分2 p三体综合征除了常见的智力障碍、发育迟缓和特征性面部外观外，偶尔还伴有神经管缺陷（NTD），如无脑畸形、脑膨出和脊柱裂。据报道，2 p24区域与NTD相关。在此，我们报告了两例由父方易位t（2; 5）（p24.3;p14.3）引起的2p24.3-pter三体和5p14.3-pter单体的同胞病例。两兄妹中，姐姐患有脊柱裂。我们测定了染色体断裂点的核苷酸序列，发现2 p三体和5 p单体片段的大小分别为18.77和17.89 Mb。NTD存在于四个先前报道的7例患者三体2 p和单体5 p，以及在本研究中检查的两名患者之一。虽然9例患者的5 p单体大小相似，但本文报道的2例患者的2 p三体大小最小。当9例患者的临床特征进行比较，目前的两名患者，姐姐有轴后多趾的左脚除了特征性的面部外观和脊柱裂，表明这些功能与三体2p24.3-pter。据我们所知，这是第一个研究脊柱裂，以确定断裂点的核苷酸序列的三体2p24.3-pter和单体5p14.3-pter。剂量敏感基因或三体区段（2p24.3）的基因剂量增加可能与2 p三体患者的NTD相关。
Partial trisomy 2p syndrome is occasionally associated with neural tube defects (NTDs), such as anencephaly, encephalocele, and spina bifida, in addition to common features of intellectual disability, developmental delay, and characteristic facial appearance. The 2p24 region has been reported to be associated with NTDs. Here, we report the cases of 2 siblings with trisomy 2p24.3-pter and monosomy 5p14.3-pter caused by the paternal translocation t(2; 5)(p24.3;p14.3). Of the two siblings, the elder sister had spina bifida. We determined the nucleotide sequences of the chromosomal breakpoints and found that the sizes of trisomy 2p and monosomy 5p segments were 18.77 and 17.89 Mb, respectively. NTDs were present in four of seven previously reported patients with trisomy 2p and monosomy 5p as well as in one of the two patients examined in the present study. Although the monosomy 5p of the nine patients were similar in size, the two patients reported here had the smallest size of trisomy 2p. When the clinical features of the nine patients were compared to the present two patients, the elder sister had postaxial polydactyly of the left foot in addition to the characteristic facial appearance and spina bifida, indicating that these features were associated with trisomy 2p24.3-pter. To our knowledge, this is the first study on spina bifida to determine the nucleotide sequences of breakpoints for trisomy 2p24.3-pter and monosomy 5p14.3-pter. Increased gene dosages of dosage-sensitive genes or genes at the trisomy segment (2p24.3) of the presented patients could be associated with NTDs of patients with trisomy 2p.