Genetic Testing in Neonates and Children

Study Notes

Screening aims to identify congenital abnormalities, developmental delays, and dysmorphism in newborns and children.
Congenital abnormalities are conditions present at birth that deviate from standard development.

Limb Anomalies (Dysmelya): Includes conditions such as amelia, ectrodactyly, phocomelia, polydactyly, syndactyly, and achondroplasia.
Heart Anomalies: Common issues include patent ductus arteriosus, atrial septal defect, ventricular septal defect, and tetralogy of Fallot.
Nervous System Anomalies: Conditions like neural tube defects, Arnold-Chiari malformation, macrocephaly, and polymicrogyria.
Gastrointestinal Anomalies: Encompass various forms of stenosis, atresia, and imperforate anus.

Idiopathic: Unknown causes account for the majority of congenital abnormalities.
Genetic and Environmental Factors: Conditions like spina bifida and cleft lip may arise from genetic predisposition combined with environmental toxins during pregnancy.
First Trimester Conditions: Certain diseases during the first nine weeks of pregnancy can lead to congenital defects.
Inherited Causes: Chromosomal abnormalities passed from parents can contribute to congenital conditions.

Neural Tube Defect: Maternal serum AFP and ultrasound (USG) recommended for screening.
Phenylketonuria: Diagnosed through blood and urine tests in neonates.
Congenital Hypothyroidism: Testing involves measuring thyroxine (T4) or thyroid-stimulating hormone (TSH) levels.
Maple Syrup Urine Disease: Diagnosis via serum levels of branched-chain amino acids.
Galactosemia: Screening performed through urine or serum assessment for galactose.
Cystic Fibrosis: Prenatal DNA testing identifies carriers; neonatal diagnosis checks for high sweat chloride levels.
Trisomy Conditions: Prenatal testing methods include amniocentesis, chorionic villus sampling (CVS), and triple marker tests.

Refers to delays in physical, cognitive, behavioral, emotional, or social development compared to normative milestones.

Genetic Factors: Includes genetic or chromosomal abnormalities.
Environmental Factors: Exposure to harmful agents, poor maternal nutrition, and infections during pregnancy can increase risk.

Behavioral Indicators:
- Difficulty maintaining attention or prolonged focus on activities compared to peers.
- Preference for unusual objects over social interaction.
- Limited eye contact and excessive frustration with simple tasks.
- Aggressive behavior, stubbornness, and frequent violent actions.
- Repetitive behaviors such as rocking, talking to oneself, or staring into space.