http://www.revistadechimie.ro REV.CHIM.(Bucharest)♦70♦ No. 7 ♦2019 2574 *email: crenguta.albu@yahoo.com All authors contributed equally to this article Early Prenatal Diagnosis of an Extremely Rare Association of Down Syndrome and Transposition of the Great Vessels CRISTINA CRENGUTA ALBU 1 *, DINU-FLORIN ALBU 2 , STEFAN-DIMITRIE ALBU 3 , ANCA PATRASCU 4 , ANA-ROXANA MUSAT 5 , ALEXANDRU MARIAN GOGANAU 6 1 University of Medicine and Pharmacy Carol Davila, Department of Genetics, 37 Dionisie Lupu Str., 020021, Bucharest, Romania 2 University of Medicine and Pharmacy Carol Davila, Department of Obstetrics and Gynecology, 37 Dionisie Lupu Str., 020021, Bucharest, Romania 3 University of Medicine and Pharmacy Carol Davila, Faculty of Dental Medicine, 37 Dionisie Lupu Str., 020021, Bucharest, Romania 4 University of Medicine and Pharmacy of Craiova, Department of Obstetrics and Gynecology, 2 Petru Rares Str., 200349, Craiova, Romania 5 Genetic Lab, 9 Drossu Nicolae Str., 012071, Bucharest, Romania 6 University of Medicine and Pharmacy of Craiova, Department of General Surgery, 2 Petru Rares Str., 200349, Craiova, Romania Every year, an estimated 7.9 million infants (6% of worldwide births) are born with serious birth defects [1]. Congenital cardiovascular defects make up one of the largest groups of severe congenital malformations [2].The incidence of congenital heart defects in different studies varies from about 4/1,000 to 50/1,000 live births [3]. Congenital heart disease is frequently described in patients with Down syndrome and is the main cause of death in this population during the first two years of life [4]. Trisomy 21 with cardiovascular malformations have a maternal age-adjusted regional prevalence of 4.33/10,000 for the white population and 3.70/10,000 for the nonwhite population [5]. Prenatal diagnosis of congenital heart disease is important for proper perinatal and neonatal management, as congenital cardiac malformations occurs in approximately eight of 1000 live births [6]. We present an extremely rare case of early prenatal diagnosis and management of a fetus with trisomy 21 associated with the transposition of the great vessels, one of the most mysterious congenital cardiac malformations. Keywords: prenatal diagnosis, congenital heart defects, transposition of the great vessels, trisomy 21, ultrasound, genetic conseling. Down’s syndrome is a genetic condition in which a person has 47 chromosomes instead of 46, with an additional replica of chromosome number 21 [7]. Down syndrome, also known as trisomy 21, is the most common genetic disorder in newborns, with a frequency of 1:1000 livebirths [8]. This particular trisomy is frequently associated with a varied combination of morphological and structural birth defects like congenital mental disability, hypotonia, characteristic body features, heart defects, and other systemic congenital malformations [9]. The association between Down syndrome and congenital heart disease has been well established since 1950, when the incidence and the type of congenital heart malformations present in newborns and infants with Down syndrome was thoroughly described [10]. Annually in the European Union, 36 000 children are live born with congenital heart disease and 3000 who are diagnosed with congenital heart disease die as a terminations of pregnancy for fetal anomaly, late fetal death, or early neonatal death [11]. Congenital heart defects reduce survival in Down syndrome patients by 72% [12]. Some forms of congenital heart disease can potentially be prenatal detected in utero, especially the severe ones with considerable fetal and postnatal morbidity and mortality [13]. So, the prenatal ultrasound screening and genetic testing are absolutely necessary for the early detection of congenital fetal abnormalities [14]. During prenatal ultrasound examinations it is important to examine the fetal face and skull because abnormalities of these structures may indicate the presence of other, more subtle anomalies like congenital heart defects, syndromes, chromosomal abnormalities trisomy 21, or even rarer conditions, such as infections, metabolic disorders [15]. Early prenatal diagnosis and treatment of congenital heart disease is of prime importance to improve the quality of life of children with Down syndrome [12]. The atrioventricular canal is the classic congenital heart anomaly in Down syndrome [16]. The transposition of the great vessels was first described by Mathew Baillie in 1797, in the second edition of the book The Morbid Anatomy of Some of the Most Important Parts of the Human Body [17, 18]. Transposition of the great vessels is a group of congenital cardiac malformations involving an abnormal spatial arrangement of any of the great vessels [19]. The incidence is estimated at 1 in 3,500-5,000 live births, with a male-to-female ratio 1.5 to 3.2:1 [18]. In Europe, it is the fourth most common type of major cardiac defect, representing 5% of all congenital heart disease [20, 21]. Also, transposition of the great vessels is one of the most severe cyanotic heart defect, an one of the most mysterious congenital heart disease, with is still unknown aetiology, very rarely associated with genetic syndromes, such as Turner, Noonan, Williams or Marfan syndromes, and in Down syndrome, it is virtually absent [18, 21]. Experimental part A 39-years-old, healthy woman, pregnant for the first time comes to our clinic for an ultrasound investigation as part of the routine pregnancy control.