Department of Clinical Genetics, National Research Centre, Cairo, Egypt.
JAMA Ophthalmol. 2013 Aug;131(8):1057-66. doi: 10.1001/jamaophthalmol.2013.644.
The study establishes the importance of genetic background for the expression of Down syndrome phenotype.
To define the ocular manifestations of Down syndrome in infants and children in Cairo, Egypt, a historically isolated region, and compare them with systemic features and with findings in other geographic groups.
We prospectively studied the ocular status and systemic features of 90 infants and children with Down syndrome and monitored all patients for 3 years. The complete ophthalmic examinations were performed along with ultrasonography, if media opacities were evident. Thyroid and cardiac status were assessed. An extensive literature search for comparison was performed.
Outpatient clinical genetics department at the National Research Centre in Cairo, Egypt.
Ocular and systemic manifestations of Down syndrome in infants and children in Cairo, and comparison of these features with patients with this anomaly from other geographic regions and ethnic populations.
Fifty-two infants or children (58%) had at least 1 abnormal ocular finding identified at the first visit. Significant refractive errors (in 37 [41%] patients) were the most common. Nasolacrimal duct obstruction, blepharoconjuctivitis, or conjunctivitis was found in 18 (20%), strabismus in 13 (14%), cataract in 5 (6%), nystagmus in 3 (3%), and optic nerve dysplasia in 2 (2%). Brushfield spots were not found. Additional ocular features developed over time. Thirty-six patients (40%) had congenital heart defects, and many (31 [86%]) had associated ocular disorders; a statistically significant correlation with myopia was established. Chromosomal translocations were high. The phenotype in Cairo was distinct.
More than half of infants and children with Down syndrome in Cairo had ophthalmic abnormalities; myopia was correlated with congenital heart defects. Comparison of the specific ocular features in our population with those in previous worldwide studies shows differences that may be related to overexpression or polymorphisms of key, modifying genes or other mutations in this historically isolated region along the Nile River. Down syndrome is more common in the highly consanguineous and multiparous Middle Eastern populations, and our Cairo findings underscore regional differences.
该研究确立了遗传背景对唐氏综合征表型表达的重要性。
确定埃及开罗历史上孤立地区婴儿和儿童唐氏综合征的眼部表现，并将其与全身特征和其他地理群体的发现进行比较。
我们前瞻性地研究了 90 名唐氏综合征婴儿和儿童的眼部状况和全身特征，并对所有患者进行了 3 年的监测。如果发现眼部有混浊，我们会进行完整的眼科检查，包括超声检查。评估甲状腺和心脏状况。我们还进行了广泛的文献搜索以进行比较。
埃及开罗国家研究中心的门诊临床遗传学系。
开罗婴儿和儿童唐氏综合征的眼部和全身表现，并将这些特征与来自其他地理区域和种族人群的此类异常患者进行比较。
在首次就诊时，52 名婴儿或儿童（58%）至少有 1 种异常眼部发现。最常见的是明显的屈光不正（37 例[41%]）。鼻泪管阻塞、睑结膜炎或结膜炎 18 例（20%），斜视 13 例（14%），白内障 5 例（6%），眼球震颤 3 例（3%），视神经发育不良 2 例（2%）。未发现Brushfield 斑。随着时间的推移，还出现了其他眼部特征。36 名患者（40%）患有先天性心脏病，许多（31[86%]）伴有眼部疾病；与近视有统计学显著相关性。染色体易位率较高。开罗的表型是独特的。
开罗的唐氏综合征婴儿和儿童中有一半以上有眼部异常；近视与先天性心脏病有关。将我们人群的特定眼部特征与以前的全球研究进行比较表明，这些差异可能与关键修饰基因的过度表达或多态性有关，或者与尼罗河流域这个历史上孤立的地区的其他突变有关。唐氏综合征在高度近亲结婚和多产的中东人群中更为常见，我们在开罗的发现强调了地区差异。
