A newborn girl is examined in the delivery room immediately after induced vaginal delivery for fetal growth restriction. She was born to a 40-year-old woman with no significant medical history. In addition to fetal growth restriction, a prenatal ultrasound demonstrated a ventricular septal defect. Her parents declined additional prenatal testing. The patient's weight and head circumference are <5th percentile. Examination shows hypertonia and closed fists, with the second digit overlapping the third and the fifth overlapping the fourth. Based on this patient's presumed chromosomal abnormality, which of the following additional physical findings is most likely to be present on examination?

A. Cat-like cry

B. Cutis aplasia

C. Micrognathia

D. Microphthalmia

E. Transverse palmar crease

F. Webbed neck

Trisomy 18 (Extra chromosome 18) 

⬇️

🧠 Abnormal Gene Expression

⬇️

Interference with normal fetal development

⬇️

Multiple System Involvement

 1. Fetal Growth Restriction (FGR)
Placental abnormalities
⬇️
Reduced nutrient and oxygen delivery to the fetus
⬇️
🧠 Inadequate fetal growth
⬇️
Fetal Growth Restriction

2. Ventricular Septal Defect (VSD)
Impaired cardiac development from abnormal gene expression
⬇️
Incomplete formation of ventricular septum
⬇️
Blood shunting between left and right ventricles
⬇️
🧠 Oxygen-poor blood mixing with oxygen-rich blood
⬇️
Ventricular Septal Defect (VSD)

3. Hypertonia
Abnormal brain development
⬇️
Disruption in motor control centers
⬇️
🧠 Increased muscle tone
⬇️
Hypertonia (increased muscle stiffness and resistance)

4. Overlapping Fingers
Impaired limb development from chromosomal abnormality
⬇️
Interference in proper hand formation
⬇️
🧠 Tendon and bone malpositioning
⬇️
Overlapping Digits (second overlaps third, fifth overlaps fourth)

5. Micrognathia
Chromosomal influence on craniofacial growth
⬇️
Insufficient jaw development
⬇️
🧠 Reduced mandibular size
⬇️
Micrognathia (small jaw)

6. Neurological Impairment & Intellectual Disability
Brain developmental delays
⬇️
Abnormal cortical and subcortical growth
⬇️
🧠 Cognitive and motor deficits
⬇️
Intellectual Disability

7. Short Life Expectancy
Multiple congenital malformations (cardiac, craniofacial, musculoskeletal)
⬇️
🧠 High vulnerability to organ failure and infections
⬇️
Reduced quality of life and survivability
⬇️
Life expectancy <1 year

Explanation of Other Answers

Cat-like cry (A), Cutis aplasia (B), and Microphthalmia (D) are all more closely associated with cri-du-chat syndrome and trisomy 13 rather than trisomy 18.

Transverse palmar crease (E) is a hallmark of Down syndrome, and Webbed neck (F) is associated with Turner syndrome, not Trisomy 18.

Flashcards

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