Subtelomeric FISH uncovers trisomy 14q32: lessons for imprinted regions, cryptic rearrangements and variant acrocentric short arms.
Subtelomeric FISH uncovers trisomy 14q32: lessons for imprinted regions, cryptic rearrangements and variant acrocentric short arms.
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DOI：
10.1002/ajmg.10703
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发表时间：
2002-09
期刊：
影响因子：
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通讯作者：
V. Sutton;K. J. Coveler;S. Lalani;C. Kashork;L. Shaffer
中科院分区：
文献类型：
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作者：
V. Sutton;K. J. Coveler;S. Lalani;C. Kashork;L. Shaffer
最近发展的一套染色体特异性，亚端粒探针已被证明在诊断和复发风险咨询患者和家庭与智力迟钝和进一步表征已知的染色体异常有用。隐匿的亚端粒重排可能占特发性中重度智力迟钝病例的7.5%。我们介绍了亚端粒荧光原位杂交（FISH）检测14q三体的分子细胞遗传学研究。我们的患者是一名3岁女孩，患有生长发育迟缓，髓膜脑膜膨出，胼胝体部分发育不全，远端畸形，口斜，耳单纯性，下颌骨小，先天性心脏病（心房和室间隔缺损伴主动脉下圆锥）。g带染色体分析明显正常。一组基于fish的亚端粒区域特异性探针显示该儿童存在14q三体。亲本FISH研究证实，母亲是14号染色体远端长臂和22号染色体短臂之间半隐性易位的平衡携带者。FISH分析使用两个含有印迹基因MEG3和DLK1的BAC克隆，这些基因定位于14q32，确定我们的患者有两个这些基因的母系拷贝。因为孩子没有母亲UPD 14综合征的特征，这个病例表明，是父亲表达基因的缺失，而不是母亲表达基因的过度表达，导致了母亲UPD 14表型。
The recent development of a set of chromosome-specific, subtelomeric probes has proved useful in diagnosis and recurrence risk counseling of patients and families with mental retardation and in further characterization of known chromosomal abnormalities. Cases of cryptic, subtelomeric rearrangements may account for up to 7.5% of cases of idiopathic moderate-severe mental retardation. We present the molecular cytogenetic studies of trisomy 14q detected by subtelomeric fluorescence in situ hybridization (FISH). Our patient is a 3-year-old girl with growth and developmental delay, myelomeningocele, partial agenesis of the corpus callosum, hypertelorism, tented mouth, simple ears, small mandible, and congenital heart disease (atrial and ventricular septal defects with subaortic conus). G-banded chromosome analysis was apparently normal. A set of FISH-based, subtelomeric, region-specific probes revealed trisomy for 14q in the child. Parental FISH studies established that the mother is a balanced carrier for a half-cryptic translocation between the distal long arm of chromosome 14 and the short arm of chromosome 22. FISH analysis using two BAC clones that contain the imprinted genes MEG3 and DLK1, which localize to 14q32, established that our patient has two maternal copies of these genes. Because the child does not have features of the maternal UPD 14 syndrome, this case suggests that it is absence of expression of a paternally expressed gene, rather than overexpression of a maternally expressed gene, that is responsible for the maternal UPD 14 phenotype.