PDF(Pubmed)
Abstract：
Trisomy 18 is a chromosomal disease, caused by the presence of a supernumerary chromosome 18. Mortality among infants with trisomy 18 is high, secondary to lethal malformations associated with this syndrome. The purpose of this study was to describe the clinical and cytogenetic features of these patients, as well as the role of genetic counselling. We conducted a cross-sectional descriptive study over a 5-year period, from July 2015 to April 2019. The study involved, patients followed up in the Department of Medical Genetics at the University Hospital Center Ibn Rochd of Casablanca, having abnormalities suggestive of trisomy 18, then confirmed by cytogenetic study. The study enrolled 5 patients, 3 girls and 2 boys (female predominance; sex-ratio = 0,67) with clinically suspected Edward\'s syndrome, then confirmed by cytogenetic study. The mean age at diagnosis was 37.40 ± 23.98 days (9 days-2 months). Trisomy 18 was clinically suspected in two cases based on facial dysmorphism and malformative syndrome, a recognizable pattern of chromosomal abnormality. Two patients were hospitalized in the intensive care unit for decompensated heart failure associated with congenital heart disease, while one patient had neonatal respiratory distress associated with polymalformative syndrome at diagnosis. Cytogenetic study confirmed the diagnosis of free and homogeneous trisomy 18 in five patients, then genetic counselling was performed. The prevalence of trisomy 18 is variable. Global prevalence is estimated at 1/6000 live births, females are mostly affected. The diagnosis of trisomy 18 should be suspected at birth in newborns with typical craniofacial dysmorphism, arms lifted in supplication and permanent flexion of the fingers, the index finger overlapping the 3rd finger, the little finger overlapping the 4th finger. There are several malformations associated with trisomy 18. This syndrome should be also suspected in the antenatal period in patients with abnormalities on obstetric ultrasound. Moreover, survival is low and only one in 10 newborns reach the first year of life.
摘要：
18三体是一种染色体疾病,由多余的18号染色体的存在引起的。18三体婴儿的死亡率很高，继发于与该综合征相关的致命畸形。这项研究的目的是描述这些患者的临床和细胞遗传学特征，以及遗传咨询的作用。我们进行了为期5年的横断面描述性研究，从2015年7月到2019年4月。这项研究涉及,患者在卡萨布兰卡大学医院中心伊本·罗赫德的医学遗传学系随访，有异常提示18三体，然后通过细胞遗传学研究证实。该研究招募了5名患者，3名女孩和2名男孩（女性占主导地位；性别比=0.67），临床怀疑爱德华综合征，然后通过细胞遗传学研究证实。诊断时的平均年龄为37.40±23.98天(9天-2个月)。根据面部畸形和畸形综合征，有2例临床怀疑18三体，染色体异常的可识别模式。两名患者因先天性心脏病相关的失代偿性心力衰竭在重症监护室住院，而1例患者在诊断时出现新生儿呼吸窘迫伴多形性综合征。细胞遗传学研究证实了5例患者的游离和同质18三体的诊断，然后进行遗传咨询。18三体的患病率是可变的。全球患病率估计为1/6000活产，女性大多受到影响。在具有典型颅面畸形的新生儿出生时应怀疑18三体的诊断，手臂在恳求和手指永久弯曲时抬起，食指与第三根手指重叠，小手指与第四根手指重叠。有几种畸形与18三体有关。对于产科超声检查异常的患者，在产前也应怀疑该综合征。此外，存活率很低，只有十分之一的新生儿达到生命的第一年。
