Courtens W, Speleman F, Messiaen L, Bormans J, Van Roy N, Vamos E
Department of Medical Genetics, Brugmann University Hospital, Brussels, Belgium.
Am J Med Genet. 1997 Sep 5;71(4):479-85.
A boy presented at 5 weeks with a syndrome of pre- and postnatal growth retardation, microcephaly, muscular hypotonia, and facial anomalies resembling those seen in Seckel syndrome or microcephalic primordial dwarfism I. Analysis of prometaphase chromosomes, fluorescent in situ hybridization (FISH), and molecular studies showed the presence of a de novo chromosome 2 deletion that could be defined as del(2)(q33.3q34)pat. Parental chromosomes were normal, except for the presence of a paternal supernumerary marker identified by FISH as der(15). On follow-up of the patient during the next months length development appeared normal and the diagnosis of Seckel syndrome was withdrawn. Clinical findings of previously published cases with interstitial deletion of at least 2q33.3-q34, the deletion present in the propositus, are reviewed and include pre- and postnatal growth retardation, psychomotor retardation, microcephaly, micrognathia, and abnormal/low-set ears; findings also present in the propositus. These findings resemble those described in the Seckel syndrome. Noteworthy is the finding that 2/3 of the 60 reviewed cases originally reported as having Seckel syndrome apparently belong to a heterogeneous group of low birth weight microcephalic dwarfism I yet to be clearly defined. In these patients no chromosome 2q deletion has been reported so far. Retrospective analysis could show if a subgroup of these patients carry submicroscopic deletions at 2q33.3-q34. Alternatively, molecular analysis of this region may be warranted in newly diagnosed patients with Seckel syndrome-like manifestations.
一名5周大的男童表现出产前和产后生长迟缓、小头畸形、肌张力减退以及面部异常，这些表现与Seckel综合征或I型小头原始侏儒症相似。对其前中期染色体进行分析、荧光原位杂交（FISH）以及分子研究显示存在一条新生的2号染色体缺失，可定义为del(2)(q33.3q34)pat。除了通过FISH鉴定出父亲有一条额外的标记染色体der(15)外，父母的染色体均正常。在接下来的几个月对该患者进行随访时，其身高发育正常，Seckel综合征的诊断被撤销。对先前发表的至少存在2q33.3 - q34间质性缺失（先证者所具有的缺失）病例的临床发现进行了回顾，包括产前和产后生长迟缓、精神运动发育迟缓、小头畸形、小颌畸形以及耳朵异常/低位；这些发现也出现在先证者身上。这些发现与Seckel综合征中所描述的相似。值得注意的是，在60例最初报告为患有Seckel综合征的回顾病例中，有2/3显然属于一个尚未明确界定的低出生体重小头侏儒症I型的异质性群体。到目前为止，在这些患者中尚未报告有2号染色体q缺失。回顾性分析可以显示这些患者中是否有一个亚组在2q33.3 - q34存在亚显微缺失。或者，对于新诊断的有Seckel综合征样表现的患者，可能有必要对该区域进行分子分析。
