Levy-Mozziconacci A, Lacombe D, Leheup B, Wernert F, Rouault F, Philip N
Centre de génétique médicale et Inserm U242, hôpital d'enfants de la Timone, Marseille, France.
Arch Pediatr. 1996 Aug;3(8):761-8. doi: 10.1016/0929-693x(96)82157-9.
Most of the children with Di George syndrome and 60% of patients with velocardiofacial syndrome exhibit a microdeletion within chromosome 22q11. The phenotypic expression of this chromosomal abnormality is highly variable.
Forty-nine children, 0 to 15 years of age, were demonstrated as carriers of a 22q11 microdeletion. The main referral diagnoses were: Di George syndrome (19 cases), velocardiofacial syndrome (14 cases); congenital heart defect with dysmorphism (9 cases); hypoparathyroidism (2 cases). The microdeletion was detected by fluorescent in situ hybridization with probes specific of the 22q11 region.
Facial dysmorphism was the only constant feature. A congenital heart defect was present in 84% of cases. Significant hypocalcemia was documented in 51% of cases and thymic hypo or agenesis in 83%. Significant immune deficiency was documented in nine cases. The most frequent associated defects were urinary tract malformations (8 cases). A cleft palate was present in height enfants but velopharyngeal insufficiency was almost constant. Two-thirds of children had psychomotor delay, and five children exhibited behavioral problems. Of the 35 couples of parents tested, eight mothers were found to be carriers of the deletion.
For the pediatrician, it is essential to know the variability of the clinical picture. The long-term prognosis is conditioned by the possibility of mental retardation and learning disabilities. Parents should be tested for the presence of the deletion. The occurrence of the microdeletion in asymptomatic relatives raises difficult problems in genetic counselling.
大多数患有迪乔治综合征的儿童以及60%的腭心面综合征患者在22号染色体q11区域存在微缺失。这种染色体异常的表型表达高度可变。
49名0至15岁的儿童被证实为22q11微缺失的携带者。主要转诊诊断为：迪乔治综合征（19例）、腭心面综合征（14例）；先天性心脏缺陷伴畸形（9例）；甲状旁腺功能减退（2例）。通过使用22q11区域特异性探针的荧光原位杂交检测到微缺失。
面部畸形是唯一持续存在的特征。84%的病例存在先天性心脏缺陷。51%的病例记录有明显低钙血症，83%有胸腺发育不全或无胸腺。9例记录有明显免疫缺陷。最常见的相关缺陷是泌尿系统畸形（8例）。8名儿童有腭裂，但几乎都存在腭咽闭合不全。三分之二的儿童有精神运动发育迟缓，5名儿童有行为问题。在接受检测的35对父母中，发现8名母亲是缺失携带者。
对于儿科医生来说，了解临床表现的变异性至关重要。长期预后取决于智力迟钝和学习障碍的可能性。应对父母进行缺失检测。无症状亲属中微缺失的出现给遗传咨询带来了难题。
