Department of Medical Genetics, University of Campinas (UNICAMP), Campinas, SP, Brazil.
J Appl Genet. 2010;51(2):219-21. doi: 10.1007/BF03195732.
Midline facial defects with hypertelorism (MFDH) are mainly characterized by ocular hypertelorism and bifid nose. They are often associated with structural and functional anomalies of the central nervous system similar to those found in 22q11.2 deletion syndromes. In addition, there are some isolated reports of MFDH and 22q11.2 deletion. These findings suggest that MFDH may be part of the spectrum of 22q11.2 deletion syndromes. To test this hypothesis, 10 individuals with MFDH were analyzed by fluorescent in situ hybridization (FISH), but no 22q11.2 deletion was detected. In view of this result, the TBX1 gene located within the 22q11.2 candidate region was screened. A new sequence variant (1132GA) was identified in one patient. This variant was not found in 110 control individuals genotyped. Considering the rarity of this condition and results of this study, the involvement of the 22q11.2 chromosomal region in the pathogenesis of MFDH could not be excluded.
中线面部缺损伴眼距过宽（MFDH）主要表现为眼球距过宽和鼻分叉。它们常与 22q11.2 缺失综合征中发现的类似的中枢神经系统结构和功能异常相关。此外，也有一些 MFDH 和 22q11.2 缺失的孤立报道。这些发现表明 MFDH 可能是 22q11.2 缺失综合征谱的一部分。为了验证这一假设，对 10 名 MFDH 患者进行了荧光原位杂交（FISH）分析，但未检测到 22q11.2 缺失。鉴于这一结果，对位于 22q11.2 候选区域内的 TBX1 基因进行了筛选。在一名患者中发现了一个新的序列变异（1132GA）。该变异在 110 名经基因分型的对照个体中未发现。考虑到这种情况的罕见性和本研究的结果，不能排除 22q11.2 染色体区域参与 MFDH 的发病机制。
