Ginocchio Virginia M, De Brasi Daniele, Genesio Rita, Ciccone Roberto, Gimelli Stefania, Fimiani Francesco, de Berardinis Teresa, Nitsch Lucio, Banfi Sandro, Magli Adriano, Della Casa Roberto
Department of Pediatrics, Federico II University, Naples, Italy.
Eur J Med Genet. 2008 Nov-Dec;51(6):658-65. doi: 10.1016/j.ejmg.2008.07.011. Epub 2008 Aug 13.
About 20% of cases with 7q deletion syndrome is associated with holoprosencephaly (HPE), due to deletion of the Sonic Hedgehog (SHH) gene (mapping to 7q36). The occurrence of severe forms of holoprosencephaly is higher in cases of 7q deletion associated with partial trisomies involving different parts of the genomes than in patients with pure 7q deletion. All cases of 7q deletion associated with 3p duplication reported to date have been associated with severe forms of holoprosencephaly, and a gene(s) on distal 3p has (have) been hypothesized to be responsible for HPE phenotype when in triple dose. Here we describe a patient with unbalanced 3p;7q translocation, showing 7q deletion (including SHH gene) and 3p duplication (complete karyotype was 46,XY,der(7)t(3;7)(p26.3;q36.1)), presenting with a relatively mild phenotype, consisting of microphthalmia and microcephaly, without cerebral anomalies typical of holoprosencephaly. Possible involvement of some genes on 3p in determining such a mild phenotype is discussed.
约20%的7q缺失综合征病例与全前脑畸形（HPE）相关，这是由于音猬因子（SHH）基因缺失（定位于7q36）所致。与涉及基因组不同部分的部分三体相关的7q缺失病例中，严重形式的全前脑畸形的发生率高于单纯7q缺失患者。迄今为止报道的所有与3p重复相关的7q缺失病例均与严重形式的全前脑畸形相关，并且有人推测，远端3p上的一个或多个基因在三倍剂量时会导致HPE表型。在此，我们描述了一名患有不平衡3p;7q易位的患者，表现为7q缺失（包括SHH基因）和3p重复（完整核型为46,XY,der(7)t(3;7)(p26.3;q36.1)），其表现出相对较轻的表型，包括小眼畸形和小头畸形，无全前脑畸形典型的脑异常。本文讨论了3p上某些基因在决定这种轻度表型中的可能作用。
