Evaluation and Risk Assessment of Congenital Anomalies in Neonates

Abstract

Congenital anomalies (CA) are a large heterogeneous group of disorders of abnormal morphogenesis or biochemistry which present at birth and carry widely variable implications for morbidity and mortality. They are the leading cause of infant mortality in the USA, with an incidence of 3-4% of all births. CA are the fourth leading cause of neonatal mortality worldwide, with an estimated 295,000 deaths annually. The enormous variability in the clinical presentation in terms of severity, time of occurrence, course, complications, management, and outcomes makes the evaluation of CA complicated, highly specific, and individualized. The anomalies can impart tremendous physical, social, and emotional distress on the patient with massive emotional, social, financial, and medical implications for the family and society. The diagnosis may remain elusive despite rigorous, elaborate, and extensive investigations in many cases. While the enormous strides in genetic testing and gene modification therapy have an encouraging impact on the diagnosis and treatment, the risk assessment of recurrence in the family and population of CA remains obscure in most cases due to the lack of information and referable evidence.

Keywords: congenital anomalies; genetics; infant mortality; morphogenesis; phenotype; risk assessment.

Figure 1

Metatarsus adductus as an example of deformation due to intrauterine positioning or space constraints.

Figure 2

Amputation of digits with a constricting amniotic band as an example of disruption.

Figure 3

Examples of aneuploidy with Trisomy 21 showing an extra chromosome 21 (left) and Turner’s syndrome with missing genes from the short arm of the X chromosome (right).

Figure 4

Common structural chromosomal anomalies resulting in abnormal genotype.