Abstract Sirenomelia is characterized by a single lower limb, bilateral renal agenesis, and single umbilical artery contiguous with the aorta. Internal and/or external genitalia anomalies as well as oligo/anhydramnios may…

Abstract Trisomy 21 (Down syndrome) is the most common autosomal trisomy in newborns, and is strongly associated with increasing maternal age. Trisomy 21 results most commonly from maternal meiotic nondisjunction….

Abstract Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive disorder caused by mutations in the gene encoding the 7-dehydrocholesterol reductase (7-DHC) resulting in decreased or absent function of this enzyme responsible…

Abstract Trisomy 18 (Edwards syndrome) is the second most common autosomal trisomy in newborns. More than 90% of cases are the result of maternal nondisjunction of chromosome 18. Fetuses with…

Abstract Chromosome abnormalities can be the cause of early pregnancy loss, fetal malformations, and stillbirth. Triploidy is one such chromosome abnormality that leads to a complete extra set of chromosomes….

Abstract Trisomy 13 (Patau syndrome) is the third most common autosomal trisomy in newborns. It results from an extra chromosome 13 secondary to nondisjunction or translocation. In the United States,…

Abstract VACTERL ( v ertebral, a nal, c ardiac, t racheal, e sophageal, r enal, and l imb anomalies) association is a nonrandom association of congenital malformations. Associated findings of…

Abstract Noonan syndrome is a disorder characterized by specific facial dysmorphisms, cardiovascular defects, short stature, and variable developmental delay. Noonan syndrome should be suspected prenatally in any fetus with cystic…

Abstract Poland sequence refers to a congenital unilateral absence of the sternal costal portion of the pectoralis major muscle and ipsilateral upper limb anomalies. The incidence of Poland sequence is…